An experimental satellite has mapped the scale of GPS jamming across Europe and the Middle East from space for the first time.

The data surprised the team behind the project and indicated that satellites orbiting far from Earth aren't the only ones that experience degradation of their positioning, navigation and timing (PNT) signals, which could affect their performance and the safety of their operations.

The new measurements were made by Pulsar-0, the first satellite of the novel Pulsar navigation constellation developed by California-based Xona Space Systems. The experimental satellite orbits 310 miles (500 kilometers) above Earth, testing Xona's technology before the company begins deploying its navigation constellation of 300 spacecraft in low Earth orbit (LEO) later this year.

The purpose of the Pulsar constellation is to provide a more resilient PNT service compared to the United State's GPS network and other global navigation satellite systems (GNSS), such as Europe's Galileo or China's Beidou. The PNT signals distributed by GNSS satellites underpin many systems that our civilization relies on in everyday life, including the operation of power grids, finance operations and oil drilling.

But because GNSS satellites orbit quite far from Earth — at altitudes abve 12,000 miles (19,000 km) — the signal that ground-based receivers detect is weak and can be easily jammed.

GNSS jamming (the overpowering of GNSS signals with noise) and spoofing (which involves overriding the original signals with false ones carrying incorrect coordinates), have become almost a global emergency over the past five years.

For example, Russian jammers have been disrupting GNSS signals along Russia's western borders, officially to protect the country from Ukrainian drone attacks. Every month, this interference affects tens of thousands of flights that cruise over the region. The warring parties in the Middle East, too, use jamming and spoofing to deflect drone attacks and hide the positions of illegal ships at sea.

Xona's satellites will use a similar signal, but one that's 100 times stronger, to offer greater resiliency against such deliberate interference. But the Pulsar-0 spacecraft also carries a GPS receiver to make sure the two systems will be able to work together. When the Xona team first turned on that receiver a few months after Pulsar-0's launch last year, they were shocked by the scale of signal degradation the receiver was reporting above Europe and parts of the Middle East.

"When we fly over North America, for example, we see a beautiful signal all the time," Kaz Gunning, Xona's co-founder, told Space.com. "But as soon as we started doing any operations above Europe, we noticed that there was really something going on there. We thought we were going to see some jamming, but it's quite a bit more than we expected."

In the hardest-hit areas, the strength of the GPS signals at the satellite's altitude dropped from the regular 40 decibels to as little as 10 decibels.

Gunning says that, due to the altitude of the Pulsar-0 satellite, the map may not truthfully reflect where jamming is worst for users on the ground. The data, however, revealed that satellites in heavily used LEO suffer from some degree of GPS signal disruption all the way from France in the west to the borders of Pakistan in the east.

The measurements mean that satellites in LEO are not out of the reach of ground-based jammers, and that the PNT signals those satellites need to time-sync their operations and determine their position in space can't always be relied upon.

"You lose the GPS capability as soon as you pass over these regions," said Gunning. "That may be a problem for imaging satellites that are trying to position themselves to take images of a certain region. You can't do altitude determination, you can't do the positioning without the GPS signal. You can't even accurately point at your telecommand antenna on the ground. That's generally going to disrupt satellite operations."

Satellite constellations such as SpaceX Starlink also rely on GPS to avoid collisions with other spacecraft.

It's not just deliberate jamming and spoofing that can wreak havoc with the precious PNT signal. Severe solar storms, too, can cause serious disruptions. The Gannon superstorm in May 2024, for example, distorted the GNSS signal so much that precision farming machinery in parts of the U.S. couldn't operate for days. Technologists are therefore racing to find backup solutions to transmit the PNT signal to everyone who needs it whenever GNSS is down.

Xona hopes that the Pulsar constellation, once up and running, will make the lives of those dependent on GNSS much easier.

Gunning says that, with the superior strength of the PNT signal transmitted by the company's planned LEO constellation, existing jammers would only be able to affect about 5% of the area they can currently disrupt.

"The effect of the jamming is going to be reduced to a smaller radius," Gunning said. "The degradation area will go down, and the full lock-out radius will also go down."

Xona plans to launch a batch of six satellites in October and begin ramping up production shortly thereafter. The company raised $170 million in a "Series C" funding round this March and hopes to begin delivering basic service in early 2027.

"We expect early customers in timekeeping to begin utilizing Pulsar at the end of this year with intermittent coverage," Max Eunice, Xona's head of communications, told Space.com. "Pulsar's capability will increase with every subsequent launch, unlocking new advantages for new customer segments as our constellation fills out."

The U.S. military is looking into putting "orbital warehouses" into orbit around Earth where fuel and other materials could be stored for easy pickup by future spacecraft on satellite servicing missions.

A new U.S. military challenge aims to "accelerate operational logistics" to help the U.S. Space Force keep its satellites active and respond in a timely fashion to threats. The challenge was created amid repeated warnings that China and Russia are actively maneuvering their own satellites close to U.S. spacecraft in orbit and launching new types of orbital weaponry.

"An orbital warehouse will have the same functionality as a terrestrial warehouse: to receive, store, inspect, and cross-load supplies, while offering protection of those supplies from the environment," a Space Systems Command (SSC) spokesperson told Space.com via email. "The orbital transfer vehicles would transport the supplies to and from the orbital warehouse, or other location of interest."

The challenge, led by the SSC and SpaceWERX (the Space Force's innovation arm), is asking companies to offer fundable ideas for orbital warehouses and orbital "transfer vehicles" that can haul fuel and supplies to and from these depots, as well insight on the best orbits in which to put the depots and vehicles, and how to manage fuel and reusability for longer-term missions. A call-out this summer will offer more details.

There's no timeline available on when these orbital warehouses (or other assets) will be operationally ready, although the SSC spokesperson added that the work is linked with the new "Objective Force 2040" planning document released in April by the Space Force, defining where the branch of the U.S. military hopes to be in the next 15 years.

SSC stated that the capabilities it is looking for include in-space servicing, propulsion, orbital mechanics, robotics, autonomy, metrology (measurement tools), materials and cryogenics, ground-to-space logistics, and mission analysis.

Planning is already underway for two funded on-orbit demonstrations in 2027 to help inform the requirements of the challenge.

"Starfish Space will build and launch the US-Otter 1, which will demonstrate rendezvous and proximity operations and docking with a client vehicle in near geosynchronous orbit," the SSC spokesperson said in an email. (Geosynchronous orbit is 22,236 miles or 35,786 kilometers, above our planet, and allows a spacecraft to remain above a fixed location on Earth.)

Additionally, Astroscale U.S. plans to build and launch its Provisioner spacecraft (previously known as Astroscale Prototype Servicer–Refueler, or APS-R) in partnership with the Air Force Research Laboratory (AFRL), the Defense Innovation Unit (DIU), and two directorates of SSC. The demonstration will use fuel from DIU, stored on a commercial Orbit Fab depot. Provisioner would then be used to refuel satellites owned by the government: AFRL Tetra-5, and so-far undisclosed SDA satellites.

SSC, the spokesperson stated, fully expects warehouses will be key to future missions using capabilities like those demonstrated by Astroscale U.S. (the American subsidiary of Tokyo-based Astroscale) and Starfish Space.

A broad sweep of entities can participate in the challenge: anything from startups and small businesses, to larger companies, academia and research labs.

Editor's note: This story was updated at 12:45 p.m. ET on June 15 to clarify that Astroscale U.S. (rather than Astroscale) is involved in this project, and that the company's spacecraft is now known as Provisioner.

Did you ever see an Iridium flare? For two decades until 2019, these communication satellites would become dazzlingly bright for a second or so in the night sky. I used to see them by accident before discovering that some websites and apps could forecast precisely when and where they would occur. I got so obsessed with Iridium flares that I would build my stargazing sessions around them. Eventually, I started trying to take night sky images just as they flared. Why? In a long exposure, the flare produced a diamond-shaped light. It was beautiful. I carried on doing the same for the International Space Station (ISS), capturing it racing across the night sky, again to a tight pre-determined schedule.

Then SpaceX came along. After launching the non-flaring replacements for Iridium in May 2019, SpaceX began launching its Starlink satellites into low Earth orbit. There were complaints about their brightness from astrophotographers, who saw their streaks in long exposure photos, but for stargazers, they were initially a delight. Each time SpaceX launched a batch of satellites into orbit on a Falcon 9 rocket, a string of moving lights could be seen in the night sky. It got called a "train" by some because it resembled a freight train racing through the sky. To me, it looked like an alien invasion. During COVID-19, glimpsing Starlink trains was something new to do (I spent hours on Heavens Above). Now it's something to actively avoid.

About 11,000 Starlinks later, that seems naive. Sure, there are now 12 million people worldwide who use Starlink internet access. I hope most of them are in previously off-grid communities in Africa, which was said to be one of Starlink's major selling points.

Look up soon after sunset, and Starlinks and other satellites are everywhere. As primarily a naked-eye stargazer and binocular astronomer, it doesn't particularly bother me, but for astrophotographers and both visual and radio astronomers, the mega-constellation era is a tragedy. Being photobombed by satellite streaks in images is a big problem, but so is radio interference in low Earth orbit. Astrophotographers can stack images and use software to remove trails (as if post-processing wasn't already time-consuming enough), but for astronomers, mega-constellations can hugely affect spectroscopic data and wide-field surveys, such as the Rubin Observatory.

Within a few years, there's likely to be about 40,000 Starlinks, but with Amazon and other companies preparing rival mega-constellations, a phase of hyper-expansion is about to begin. It's going to get a lot, lot worse. As with Iridium satellites, mega-constellations of satellites will eventually de-orbit, burn up and disappear from the night sky, though probably not en masse in our lifetimes.

When to see satellites

The best time to fully appreciate just how dominant satellites are becoming in the night sky is during summer in the twilight hour immediately following sunset or before sunrise. At this time of year, the sun may have dipped below your horizon, but it's not far below, so its light still shines on satellites far above you.

By the middle of the night, the sun is farther below the horizon. Satellites therefore pass through Earth's deep shadow and don't get lit by the sun, making them more or less invisible.

Stargazer's corner: June 12-18, 2026

Here comes a beautiful week for being outside looking west as twilight unfolds after sunset. That's because the moon reaches its new phase on Sunday, June 14, which means dark skies (albeit during short nights in the Northern Hemisphere's mid-latitudes) and a crescent moon after sunset. On June 15, you'll see a young waxing crescent with Venus, Jupiter and Mercury, with the latter as high as it gets. On June 17, the crescent passes close to Venus and the Beehive Cluster. These moments are short-lived, but they reward those willing to step outside at just the right time.

Constellation of the week: Lyra

Lyra is small (and said to resemble a harp), but it commands attention because of Vega, one of the brightest stars in the night sky. About 25 light-years away, it's one of the most studied stars and serves as a standard yardstick to measure the apparent magnitude (brightness) of other stars. It's also the brightest in the famous Summer Triangle asterism, now obvious in the east after dark.

In the cult movie Contact (1997), astronomers discover an extraterrestrial signal emanating from Vega. In reality, a recent image from the Hubble Space Telescope of a 100-billion-mile-wide disk of dust around Vega revealed no directly visible large planets.

My latest stargazing obsession: the ISS

At this time of year, true darkness is in short supply, especially at mid-northern latitudes. But twilight has its own advantages. Every 90 minutes or so, the International Space Station buzzes around Earth, but as Earth revolves beneath it, it appears to take a different trajectory. Using NASA's Spot The Station app (and many other stargazing apps), it's possible to see the dates and exact times of passes over your location over the next week or two. The app also has an augmented reality mode that lets you point your phone at the night sky to see where the ISS will appear in the west. When you see it, it will cross the sky and disappear into Earth's shadow to the east, taking between one and six minutes. Since the ISS is always brightest during twilight and the Milky Way becomes visible as twilight ends, it's a narrow window, but it is sometimes possible to image both together. If you're patient, seeing the ISS can add an extra dimension to stargazing.

SpaceX CEO Elon Musk outlined more details for his company’s planned data centers in space ahead of a widely anticipated IPO on Friday (June 12) expected to make him a trillionaire.

A new half-hour video offers a typical Elon Musk fireside chat about where the billionaire founder of SpaceX wants to be taking his technology next. In the video posted on X on Monday (June 8), Musk described launching AI satellites, with "a lot of solar cells", as well as radiators and high-speed optical (laser) links for communication. SpaceX also expects to launch an AI-satellite-focused production facility by the end of next year, to be "operating at some reasonable volume," Musk said. "So, if anybody wants to work on AI satellites, this is kind of going to become the hub of that."

The common pitch among these companies is that space is necessary to generate AI capabilities because data centers on Earth are running out of physical space to host them, as well as lacking community support out of concerns about significant power and water usage by these big computing hubs. The challenge is that orbital data centers are mostly notional, and not actually demonstrated by operating tech — at least yet. But SpaceX is confident it can develop the necessary technologies to make an AI data center constellation a reality.

The next generation of Starlink satellites SpaceX is developing already possess a lot of the tech needed to advance to AI centers, according to Musk. "A lot of this technology, we've already made for the Starlink V3 satellites," he said. "Basically, we don't think this is a super-hard problem, compared to things we already do."

Musk described "racks of compute" (referring to the banks of computer chips on each satellite) that would connect with each other through laser links between the AI satellites, as well as with Starlinks. The data could be sent to the ground using antennas, or laser links at "not a particularly high latency" (meaning, high speed).

Each AI satellite, Musk said, would generate 150 kW of power at peak, and 120 kW consistently, and would launch aboard SpaceX's heavy-lift Super Heavy and Starship vehicles the company is still testing out every few months for eventual mission operations.

The SpaceX CEO also appeared to wave off concerns about overcrowding low Earth orbit, even after numerous reports have emerged about Starlink satellites having to maneuver away from each other or from other spacecraft. (SpaceX's Starlink constellation is currently at 10,000-plus operational members, according to analyst Jonathan McDowell.)

"There's a lot of space up there, and so even when you're talking thousands, or even — you know — up to a million satellites, yeah, you got plenty of room to move around up there. Space is really big, so it's not like space is going to get crowded," Musk said in the video.

Pointing to the growth of Starlink, Musk said SpaceX is uniquely positioned to be the company delivering on orbital data centers. "We've got a pretty good idea of how to operate, just really large constellations, and do it safely now, right? We are the only operator that has any experience of that scale."

Musk periodically offers these sorts of chats for Starship and the company's Mars plans, often (as with this video) mixing in musings about where he sees "civilization" and "humanity" going next. But lately, there’s been financial incentive to add AI into the planning for SpaceX.

When the IPO drops, SpaceX plans to list its shares at $135 apiece for a value of more than $1.75 trillion — and it is heavily betting on its company xAI, and orbital data centers in space to generate AI capabilities, in its pitch to investors.

SpaceX is also in a race to attract attention from space investors, who are watching other orbital data center plans from entities ranging from big players like Google and Blue Origin and Microsoft, to smaller companies like Cowboy Space Corp. (formerly Aetherflux) and Starcloud.

Correction 6/12: The SpaceX IPO was announced on Friday (June 12) not Thursday (June 11).

The U.S Space Force has awarded SpaceX $4.16 billion to help the military track airborne targets using satellites.

The massive contract is under the Space-Based Airborne Moving Target Indicator (SB-AMTI) program, which will add space systems to the U.S. military's tracking capabilities. SpaceX is the first of nine companies that Space Force has disclosed for the SB-AMTI vendor pool. The other eight companies have yet to be publicly announced.

Space Force announced the SpaceX contract on May 29, stating that the award is for a satellite constellation that can "track and target airborne threats globally." The idea is that satellites can help with tracking in places where it could be dangerous for aircraft, which the military has long used for airborne tracking capabilities. The service aims to get an SB-AMTI satellite constellation up and running by 2028.

"By focusing these capabilities to the space domain, we are providing the Joint Force with sustained battlespace awareness of contested airspace," USSF Col. Ryan Frazier, acting Space Force portfolio acquisition executive for SBST, said in a statement. "We are beginning development and integration efforts immediately to meet the program's rapid deployment milestones and address emerging national security requirements."

Space Force described the SB-AMTI architecture as a "complex system-of-systems," which will integrate space-based sensors with fast, secure communication, as well as data processing technologies on the ground.

It says that this program reflects "a rapid and strategic shift" toward a deeper collaboration between the contractors, research labs, and agencies that are collectively known as the government space industrial base.

"Our mission is to deliver a resilient sensing layer that ensures our joint warfighters maintain a decisive information advantage in the air domain — especially in a denied or contested environment," USSF Col. Frazier said in a separate statement on April 27. Denied or contested environments refer to airspace in which the U.S. military might face anti-aircraft attacks or other forces' aircraft.

Future sensors

SpaceX's satellites won't replace the current airplanes that the military uses to track moving targets. Right now, the two methods are meant to compliment each other.

In the announcement, the Space Force highlighted the need to track airborne targets from space due to "continued challenges as adversaries develop increasingly sophisticated anti-access/area-denial (A2/AD) systems."

A2/AD systems are used to prevent adversaries from entering a specific airspace. If the military moves some airborne target sensing to orbit, then it could reduce the risk to military aircraft that traditionally serve this function in contested regions.

"We are providing continuous oversight where traditional sensors cannot reach to protect their freedom of maneuver," USSF Col. Frazier said in the April 27 statement.

The Golden Dome missile defense system is one of the Trump Administration's keystone military initiatives, and these satellites would be expected to help track missiles for the Golden Dome, Reuters reports.

Space Force anticipates that it will issue more awards in the coming year, which will help to expand its diversity of vendors.

A new report stresses the strategic and security implications of placing mass drivers on the moon  — essentially electromagnetic catapults   — by arguing that these launchers could serve as valuable first strike weapons systems.

According to the theory behind them, these mass drivers could use powerful magnetic fields to throw satellites and other probes into space without the need for costly and heavy chemical propellants. Putting railguns on the moon isn't a new idea, and was most recently proposed by SpaceX as a means of launching thousands of AI data center satellites into deep space.

But according to a new report, these mass drivers are inherently dual use, meaning they can be used for both civilian and military purposes; while it's true they could help launch peaceful satellites, being large electrically-driven cannons, they could also potentially launch weapons from the moon. "This duality places mass drivers in a uniquely sensitive strategic position," the new report states. "While mass drivers can bootstrap an off-world economy, they carry an equally potent and unsettling military capability: the ability to operate as an unassailable, undetectable first-strike platform."

Written by Andre Sonntag, an independent space power and policy analyst focused on cislunar security, strategy, and near-term space conflict, the special report titled "Strategic Implications of Lunar Mass Drivers as a Dual-use Technology" was published by the American Foreign Policy Council.

It points out that the U.S. faces a narrowing window "to shape the strategic environment of the lunar frontier" and argues that developing and deploying these mass drivers will be a key factor in the spacefaring superpowers' efforts to control cislunar space.

Space colonies, solar power satellites

The idea of lunar-launched payloads dates back to the 1970s and the work of Princeton professor and space visionary, the late Gerard O'Neill.

Mass drivers are based on the coilgun design, adapted to accelerate a non-magnetic object. One application O'Neill proposed for mass drivers: toss baseball-sized chunks of ore mined from the moon's surface into space. Once in space, the lunar-lobbed ore could be used as raw material for building space colonies and solar power satellites.

O'Neill worked at MIT on mass drivers, teaming up with Henry Kolm and a group of student volunteers to build their first mass driver prototype. Backed by grants from the Space Studies Institute, follow-on prototypes improved on the mass driver concept, showing that a mass driver only 520 feet (160 meters) long could launch material off the surface of the moon.

'Unparalleled source of space power'

That launch capability, the new report argues, means these mass drivers could be "an unparalleled source of space power" that other launch systems will not be able to compete with. "For these reasons, the United States must take measurable steps towards practical development of lunar mass drivers as soon as possible," the report recommends.

If the United States does not invest in these technologies, Sonntag writes, its competitors will then be able to field them first and potentially control cislunar space. But it could be some years before the technology is ready to launch anything of significant mass.

"No mass driver architecture is currently mature enough for an immediately scalable, industrial application," Sonntag told Space.com by email. "The primary issue, regardless of architecture, is that with regards to scaling."

Current mass drivers can only launch small payloads, Sonntag said, and there are still logistical and technological barriers to scaling the concept up for larger spacecraft. But with the right investment and know-how, it might soon be possible, Sonntag said.

The report doesn't call out any companies specifically, but the idea has already been proposed by some of the biggest names in the space industry.

SpaceX CEO Elon Musk, never short of catapulting visionary quests forward, advised newly acquired xAI workers in February that he sees a need for a factory on the moon that could use on-site lunar resources to manufacture artificial intelligence (AI) data center satellites. To churn out thousands of those spacecraft each year, Musk called for a colossal catapult to be built on the lunar surface.

But many specifics of the company's concept remain unclear. "While we do not know the details of the SpaceX mass driver, they should have the resources and workforce to develop such systems," Sonntag said.

And other companies are developing their own mass driver plans, Sonntag said. "Apart from SpaceX, companies like Auriga Space and Electromagnetic Launch Inc have been working to develop the technologies for other practical mass drivers. However they are much smaller companies that would be greatly enabled by additional funding."

With that funding secured, "a commercially relevant system could be ready by the mid 2030s," he added.

First-strike platform

Mass drivers on the moon would operate largely outside existing early warning and attribution architectures, thereby complicating detection and response by existing early warning systems.

Weaponized mass driver payloads, the report suggests, could likely fall into one of three categories:

1. Kinetic Energy Impactor (KEI) - inert projectiles designed to slam into targets at high speeds
2. Satellite & Anti-Satellite (SAT/ASAT) - spacecraft or satellites designed to destroy, disrupt or degrade other spacecraft
3. Nuclear Reentry Vehicle (RV) - payloads similar to those found on intercontinental ballistic missiles designed to deliver nuclear warheads from space

A lunar mass driver could also be used to rapidly launch space-based missile defense systems such as those envisioned by the Trump administration's recent Golden Dome concept.

High throughput logistics chain

The newly-released study points out that the United Nations Outer Space Treaty prohibits military installations on celestial bodies as well as the deployment of nuclear weapons in space.

But even with the treaty, regulating any dual-use technologies is difficult. "As mass drivers are mixed use and would be primarily for civilian applications, this would heavily obfuscate the exact purpose of any system as to whether it is a military installation," the report observes.

There are recent developments in the People's Republic of China (PRC) that view mass drivers and related technologies as central to lunar industrialization and long-term space development. Chinese scientists recently suggested putting a magnetic launcher on the lunar surface in order to launch payloads into space or send resources back towards Earth, according to Sonntag's report.

"Researchers have claimed that the system could operate at roughly 10% of the cost of conventional rockets while supporting frequent, automated launches to Lunar orbit or Earth return trajectories," the report states.

Integrated with China's International Lunar Research Station plans, and broader industrialization plans by that country, mass driver capabilities would enable a sustained, high throughput logistics chain between the moon and Earth, Sonntag's report adds.

Meanwhile, as experts and governmental leaders in the United States continue to sound the alarm on how tight the race against China to establish a presence on the moon is becoming the new American Foreign Policy Council (AFPC) report stresses that the U.S. can and must shape the rules of the cislunar frontier by acting first, setting precedence before anyone else can establish their own norms.

"The United States, via the Artemis Program, should pursue an aggressive campaign to establish a distributed permanent presence at certain locations of the lunar south pole and equatorial regions," argues the report. "Having an established presence would give the United States de facto control of these strategic locations."

NASA's Artemis Accords and Artemis program of lunar exploration aim to do the same thing, along with a collation of more than 66 nations who have signed along to help establish those norms  — but with an emphasis on establishing "safe, peaceful, and prosperous future in space for all of humanity to enjoy."

DARPA is at last ready to test fueling up satellites in faraway Earth orbits, to keep those machines working a little bit longer.

DARPA's (Defense Advanced Research Projects Agency) long-delayed Robotic Servicing of Geosynchronous Satellite (RSGS) demonstrator is slated to launch as soon as this summer, the U.S. military's research and development group stated in a statement on Wednesday (May 20). And as the name suggests, robots will form an integral part of the spacecraft's work.

The heart of the mission will be a "highly dexterous robotic servicing suite", DARPA stated, that should be able to jump in on several critical tasks to help satellites needing a boost: "on-orbit upgrades, inspections, anomaly resolution, and satellite relocation."

What's more, DARPA aims to up the ambition by tackling this work far away from our planet. The program aims to service satellites in geosynchronous orbit (GEO), which is roughly 22,236 miles (35,786 kilometers) above the Earth.

These satellites, orbiting at about 90 times higher than the International Space Station (at 250 miles or 400 km), are positioned in a sweet spot allowing the speed of their orbit to match the rotation of the Earth. The satellites' positioning allows them to get a consistent view of one patch of planet, which is helpful for providing reliable telecommunications—or for performing long-term climate or defense monitoring.

But at such a distant perch from Earth, satellites in GEO typically have few options when they run out of fuel besides simply being maneuvered out of the way, for a new satellite to take their place. With space junk rising (along with collision risk between satellites), that's where DARPA and its partners on the mission aim to make a difference.

RSGS was originally announced in 2017, but has had delays for various reasons, according to Breaking Defense. The original contractor, then known as Maxar Technologies, left the project in 2019, then the pandemic interrupted the industry's supply chain distribution.

Newer prime contractor SpaceLogistics (a Northrop Grumman subsidiary) also had challenges integrating the DARPA payload on their spacecraft, the report said. But DARPA emphasized RSGS is at last ready to fly. Assuming an on-time launch, RSGS will begin work in 2027 after a 10-month journey to geosynchronous orbit using electric propulsion.

Other participants in RSGS include NASA and the U.S. Naval Research Laboratory. Working together with its partners, DARPA wants to ensure their robotic servicer is able "to adapt to a variety of on-orbit missions and conditions" with safety and efficiency in mind, according to DARPA materials.

The eventual goal is for DARPA to support a servicing spacecraft that could work for years in orbit, potentially helping out spacecraft dozens of times. What's more, the agency emphasized, the maintenance will go beyond refueling the spacecraft.

"Even fully functional satellites often have their operational lives cut short simply because they carry obsolete payloads — a frustrating situation for owners of assets worth hundreds of millions of dollars. With no support once in orbit, GEO satellites are equipped with redundant systems and maximum fuel capacity, which increases their complexity, weight, and expense," DARPA stated.

The overall approach, therefore, includes installing new payloads on the spacecraft along with doing preventative maintenance: orbit adjustments, fixing up mechanical problems, and doing inspections to address any other anomalies that may come up.

A typical geostationary satellite lasts about 15 years, according to IEEE. That is a very long time compared to say, a SpaceX Starlink in low Earth orbit or LEO (which might last five years.) But the rapid refresh rate of Starlink and other LEO satellites also ensures the tech will not get old, and that the satellites can be replaced frequently and at low cost. That's not the case in GEO.

DARPA and its partners will need to prove that they can service a geostationary satellite, which costs hundreds of millions of dollars to launch, at an affordable and rapid pace. They also are competing in a quickly growing field of other companies looking at space servicing, ranging from Astroscale to Thales Alenia Space. But the agency not only frames their approach as possible, says that the RSGS program will create a new approach to satellite operations altogether.

"By transitioning from a paradigm of disposable space assets to one of sustainable, upgradable, and resilient satellites, RSGS aims to fundamentally alter space operations for both the public and private sectors," officials wrote of the mission in a separate statement. "With launch on the horizon, the RSGS program is poised to pave the way for a more resilient and sustainable infrastructure in space."

On the morning of Jan. 8, 2025, a red dot popped up on NASA's Fire Information for Resource Management System. It was the first sign of what would become one of California's worst wildfires in history, going on to claim a dozen lives and burn down thousands of homes in the Palisades. All the while, the Aqua satellite was orbiting above, scanning the planet and beaming data down to ground stations in Alaska and Svalbard.

This satellite carries infrared sensors that capture changes on Earth impossible to see with the human eye, making it vital for coordinating emergency responders during natural disasters. Upon detection, NASA converts Aqua's infrared wave data into GPS coordinates, allowing officials to plot the spread of fire as points on a map. These coordinates make up what's known as the Moderate Resolution Imaging Spectroradiometer (MODIS), an instrument that spots fires on the Earth’s surface. This process often alerts emergency services faster than 911 calls from the ground.

But now, scientists are starting to find surprising gaps in that data. Logs maintained by NASA show multiple occasions where fire-tracking datasets reported errors. Why? Incoming space debris.

Missing data is a problem for scientists trying to explain the Earth's climate to politicians and business leaders who make decisions on what to do about climate change. While the data loss is currently small, scientists say the problem will only get worse over time as space debris increases.

But Aqua isn't alone. It's one of three main satellites that make up the core of the Earth Observing System (EOS), a constellation that coordinates orbit to measure the land, ocean and atmosphere simultaneously.

The EOS fleet has allowed us to understand how aerosols affect cloud formation, map the deforestation of the Amazon, and discover how the Earth's oceans have darkened thanks to phytoplankton blooms. And indeed, all three satellites — Aqua, Terra and Aura — are at risk from space junk. Starting in 2005, the EOS fleet swerved to avoid space debris on at least 32 occasions. The maneuvers may have left corrupted climate data in several of those instances, according to data logged by the Land Data Products Evaluations Assessment. Even beyond data, there is also the loss of precious fuel.

"Even without collisions, space debris has an economic cost," Andrew Bonwick, vice president at Relm Insurance, which offers satellite insurance and has to price in the risk of collision, told Space.com. "Each time a satellite has to maneuver to avoid a potential collision, it uses fuel which is a finite and precious resource."

"Things will get worse before they get better," said the NASA scientists in the 2018 report that assessed debris maneuvers. The report found that the risk of a collision between an EOS satellite and a piece of orbital debris is increasing.

In its heyday, Aqua flew around 438 miles (705 kilometers) above the surface of the Earth, moving from the North Pole to the South Pole in an ellipse 14 times a day, scanning the entire planet. The satellite sits in sun-synchronous orbit, capturing the light waves emitted from the Earth's surface.

Along that journey, Aqua has survived a battery short-circuiting, a solar panel thermistor failure, and lost 23 of its solar cell strings. But thanks to careful fuel management, the satellite has lasted 18 years longer than originally designed.

"If we knew we were going to have a spacecraft and instruments that would last 20 years, we might have put more fuel in it so that it would last even longer," said Aqua Project scientist Claire Parkinson in 2022.

Climate satellites like Aqua are more at risk from debris because they have to fly close to the planet to capture their data. Low Earth Orbit (LEO) has the highest amount of space junk, trapped there by the Earth's gravity and travelling at faster speeds than the upper atmosphere.

In 2005, the European Space Agency (ESA) was tracking about 16,000 pieces of debris. By 2026, that number had increased to more than 44,000, an increase of about 180%.

The vast majority of space debris is too small to be tracked, with ESA estimating that more than a million small pieces are unaccounted for. Even a speck of paint can be enough to wreck a satellite.

Space junk is created when satellites break up in orbit, either because of collisions or anti-satellite tests such as those carried out by China and Russia. On April 28, two Russian spacecraft passed within 10 feet (3 meters) of each other.

But space junk avoidance isn't the main reason satellites use fuel. If left alone, Aqua would eventually drift off course. Gravity from passing mountains and ocean bulges slowly pulls the satellite out of orbit, while solar radiation changes its spin, corrupting its data.

For that reason, scientists constantly have to correct satellite trajectories to avoid spacecraft crashing into other spacecraft or even just random bits of space junk. While it's true that spending fuel shortens the life of a satellite, avoiding space debris is usually worth it. Most of Aqua's fuel was used on orbital-course corrections.

"For applications where satellites are tasked to provide detailed imagery of particular areas, the job may just not get done, especially where the imagery is time critical or depends on frequent revisits," says Bonwick.

Now, Aqua is reaching the end of its life span. It's set to be switched off this year after traversing the skies for almost a quarter-century, leaving behind a legacy for future climate scientists. Less than 66 pounds (30 kilograms) of fuel remains, held in reserve for the time Aqua is lowered into the atmosphere and safely burned up. Until then, the satellite continues its orbit, like a car in neutral rolling down a hill.

After it's switched off in the fall, Aqua will no longer have enough fuel to dodge incoming space junk. The risk of collision for U.S. government satellites is supposed to be 1 in 1,000, but the risk increases once fuel runs out.

In 2007, when China destroyed one of its own satellites, multiple satellites had to maneuver to avoid space debris, raising concerns about the possibility of Kessler Syndrome, where satellite collisions begin to cascade, like dominoes.

There have been four confirmed space collisions, according to the ESA, but only one involving a climate satellite: An incident in 2021 when a piece of debris from a Russian Zenit-2 rocket hit China's Yunhai-1 02 meteorological satellite.

The danger is increasing, with ESA estimating a 20% rise in collision risk since 2024. Because of the increased risk, satellites have become almost uninsurable, meaning NGOs and government agencies are increasingly bearing the cost of threats to climate satellites.

MethaneSAT, a satellite designed to capture methane emissions to help better understand the greenhouse gas, stopped transmitting data in 2025 only fifteen months into its life cycle. After high solar activity, the satellite suddenly shut down. Investigators couldn't agree why.

Two years before that, the first satellite from London-based SatVu, HOTSAT-1, went into orbit for Earth observation. But only months after releasing its first images, the satellite’s infrared camera went dead. "If that satellite had not been insured, that would have killed the whole company," says Bonwick. "It's not just balance sheet protection, it's survival."

The MODIS fire-tracking dataset is set to continue until Aqua and its partner satellite Terra are turned off. NASA, which responded to an initial email from Space.com but has yet to answer specific questions concerning the issue, is continuing its fire detection capabilities through the Visible Infrared Imaging Radiometer Suite (VIIRS), a database that survives on multiple NASA satellites.

But with the space agency suffering from government cuts, private firms are now filling the gap. Google has published plans to launch a constellation of satellites specifically for fire detection, which promises to capture even smaller fires at greater resolution than before.

On May 4, Aqua celebrated its 24th birthday. It will probably be its last. It completed more than 126,000 orbits of the Earth, and enabled at least 30,000 scientific publications.

The satellite leaves behind one of the longest single-satellite climate data records ever compiled. Its contributions to climate science will be hard to replace.

Update 5/21: Bonwick's comment regarding satellite insurance possibly killing a company was in reference to the HOTSAT-1 satellite from London-based SatVu.

Vast isn't just about private space stations anymore.

The California startup, which is developing the "Haven" series of private space stations, announced today (May 19) that it will build and sell satellites as well.

The new Vast Satellite line will consist of "high-power satellite buses built for operators across communications, Earth observation, national security and orbital data center satellite constellations," the company said in a statement today.

Vast Satellite will leverage technology that the company has already demonstrated in space, on a test flight called Haven Demo.

Haven Demo launched to low Earth orbit (LEO) aboard a SpaceX Falcon 9 rocket this past November, charged with verifying the performance of systems that will be key to the Haven orbital outposts — propulsion, power and avionics, for example. Everything went well, according to Vast, and the demonstrator performed a controlled deorbit into Earth's atmosphere in February.

Haven Demo turned out to be a pathfinder for Vast Satellite as well, because Vast builds its core systems in house and will use them for the newly announced spacecraft buses, too.

"We believe Vast is uniquely positioned to compete in the high-power satellite market through the combination of our world-class engineering team, large-scale manufacturing capabilities and the on-orbit success of Haven Demo," Vast CEO Max Haot said in the same statement.

"Customers can benefit from our experience designing, building and operating flight-proven large-scale spacecraft while gaining access to highly capable, flexible spacecraft platforms backed by operational expertise," he added.

And Vast already has a customer — a confidential one that has committed to buy four satellites, with an option to purchase 200 more, according to the statement.

The first offering in the Vast Satellite line will be a 15 kilowatt-class bus "designed to support a wide array of power-intensive missions through flexible configurations," Vast wrote in the statement.

That bus will weigh about 1,540 pounds (700 kilograms) unfueled and be capable of carrying more than 770 pounds (350 kg) of payload. It's designed to operate for five years in LEO, though other orbits will be possible in the future. Vast plans to launch a batch of these spacecraft — 10 of them — to orbit for the first time in late 2027.

Meanwhile, the company continues to work on its Haven project, which aims to have the multimodule Haven-2 space station up and running by the time the International Space Station retires in the early 2030s.

The company plans to launch a pathfinder called Haven-1 in 2027. If all goes well, Haven 2's first module will lift off in 2028, with additional modules going up every six months thereafter for the next four years.

Space industry aficionados have big plans. They talk about the not so distant future when hundreds of thousands or even millions of satellites orbit planet Earth, beaming the internet to the unconnected, processing data in orbital computer centers, generating solar power and more. But this ambitious vision, which many in the sector think will become reality sooner or later, worries atmospheric researchers.

Studies show that since the beginning of the mega-constellation era in 2020, concentrations of potentially dangerous high-altitude air pollution stemming from satellite launches and re-entries has significantly increased. Based on estimates described by researchers as "conservative", the global space sector will have released by 2030 more climate-altering chemicals into the atmosphere than the entire United Kingdom. If the growth envisioned by the space industry leaders comes to pass, this air pollution, mostly concentrated in higher layers of the atmosphere, will at some point begin altering Earth's climate, Eloise Marais, a professor of atmospheric chemistry and air quality at University College London, told Space.com.

"The space industry pollution is like a small-scale, unregulated geoengineering experiment that could have many unintended and serious environmental consequences," she said.

Geoengineering is a term describing a number of possible interventions that could reverse the rise in global temperatures caused by the increasing concentrations of greenhouse gases in the atmosphere. One of the most commonly discussed geoengineering methods is the Stratospheric Aerosol Injection, which entails releasing large amounts of light-reflecting particles into the stratosphere, the second layer of Earth's atmosphere, to reduce the amount of heat reaching the planet. The idea is being studied by scientists, who warn that impacts may be unpredictable, including changes in rain patterns, draughts and unforeseen weather changes.

Marais is one of those scientists, leading a team that is studying the effects of satellite-related air pollution. Their latest study found that by 2029, air pollution from megaconstellation satellite launches — such as Starlink, Amazon Leo or Chinese projects Guowang and Quianfan — will account for more than 40 percent of all pollution generated by the space sector.

Megaconstellations — most commonly used to beam internet to users in remote areas from near Earth space — are a quickly growing trend. They rely on satellites with limited life-spans which get replaced about every five years with more modern and powerful technology. The frequent replacements mean a more frequent launching and a more frequent deorbiting compared to old-school missions designed with longer missions in mind. That in turn, means more air pollution inserted into the otherwise pristine upper layers of Earth's atmosphere.

"Most mega-constellation launches today are burning kerosine fuel, because they usually rely on Falcon 9 rockets, which are producing black carbon," Marais said. "This black carbon is being released into the higher layers of the atmosphere where it stays for 2.5 to 3 years. Because of that, that black carbon has about 540 times bigger climate effect than black carbon that's released from surface sources like ships, cars and power plants."

The researchers estimate the impact of air pollution from rocket launches by calculating the amounts of pollution likely to arise from expected satellite launches and re-entries in a given period. While satellite launches mostly produce black carbon, which has a potential to warm the upper atmosphere, satellite re-entries generate aluminum oxides, which can damage the ozone layer. The team then runs climate models that show the expected impact of the pollutants on the planet.

"The model can very nicely tell us how much ozone is going to be destroyed from this pollution and how much the climate is going to be altered from this pollution," said Marais.

Marais added the latest modelling was based on "conservative" numbers as the actual growth in satellite numbers has been consistently outstripping the researchers expectations.

Currently, over 15,000 operational satellites orbit the planet, according to the European Space Agency. That is three times more than circled Earth in 2020. The increase is mostly down to SpaceX's Starlink megaconstellation, which currently consists of more than 10,000 satellites.

New contenders, including Amazon LEO and Chinese operators Guawang and Qianfan, are in the process of building up their own fleets. By 2030, some 100,000 satellites may orbit the planet, with further steep growth expected in the coming decades.

Marais warns about an unregulated growth in satellite launches. The particles released into the upper layers of Earth's are at some point likely to reach concentrations, which will have an effect on Earth's climate.

Marais said that although by 2029 concentrations of pollutants from satellite launches and re-entries will amount to only about one hundredth of the quantity required for geoengineering interventions, the continued accumulation of the pollutant resulting from increased satellite deployments raises concerns.

"We need to be taking it far more seriously in terms of regulating the pollution that's coming from launches and reentries," said Marais. "There also needs to be far more funding funneled into research to study this because we can't keep up with the space industry."

The study was published on Thursday, May 13, in the journal Earth's Future.

Earth watched on as a communications satellite deployed its big reflector more than 22,000 miles (35,400 kilometers) away.

The satellite, ViaSat-3 F2, just deployed its large reflector after launching last November. In an image shared by the company Viasat on social media, you can see the striking results of this maneuver in space.

What is it?

ViaSat-3 F2 launched to space on Nov. 13, 2025 atop a United Launch Alliance Atlas V rocket. In the first few months after that, the telecommunications satellite made its way to geostationary orbit, which lies exactly 22,236 miles (35,786 km) above Earth. This is much farther away than low Earth orbit where the International Space Station lives, which extends to 1,200 miles (2,000 km) above Earth.

As seen in this new image, the satellite has now not only reached geosynchronous orbit, but it has fully deployed its large reflector. This step is critical to the satellite's success, as the reflector will improve its overall broadband capacity, according to recent reports.

"Exciting progress for our ViaSat-3 program, as we focus on advancing in-orbit testing of our ultra-high capacity satellite," the company wrotein its post.

Why is it incredible?

The ViaSat-3 F2 satellite is a 13,000-pound (5,900-kilogram) communications satellite designed to provide high-speed satellite internet across the Americas from space.

According to Viasat, each of the ViaSat-3 satellites (three of which have launched to date) is made "to be capable of rapidly shifting capacity throughout its coverage area to deliver bandwidth where and when it’s needed most."

We might sometimes take our connectivity here on Earth for granted. From almost anywhere, we can be instantly connected to our friends and family all around the world. This image is a captivating visual of the technology behind that connection coming to life.

President Trump's Golden Dome may end up being quite a bit more expensive than originally thought.

A new report by the nonpartisan Congressional Budget Office (CBO) estimates it will cost about $1.2 trillion to deploy the Golden Dome missile defense system and operate it for 20 years.

That's more than double the CBO estimate from last year, which was $542 billion, and about seven times higher than the number cited by the White House when it announced the project in May 2025 ($175 billion).

The Golden Dome for America (GDA) is an envisioned shield that will protect the United States against ballistic and hypersonic missiles and other aerial threats. It will feature advanced missile-tracking satellites as well as space-based interceptors — satellites capable of shooting down missiles headed toward the U.S., which the Space Force wants to be ready by 2028.

Those broad strokes are basically all we know, however; details of the architecture have not been released. So, the CBO had to get creative in its newly announced cost estimate, filling in gaps in the 2025 executive order that called for Golden Dome's creation.

The agency did that, then crunched the numbers.

"A national missile defense system possessing capabilities broadly consistent with those outlined in the executive order would cost about $1.2 trillion to develop, deploy, and operate for 20 years, CBO estimates," the 12-page report reads.

That notional system features four interceptor layers, one of which is space-based.

"The NMD system also includes additional sensors, communication systems and battle management systems to coordinate collective action among the layers," the report reads. "The layered structure of the overall system would provide the capacity to simultaneously engage multiple missiles launched by an adversary. Each layer would be able to operate independently if interaction with national command and control was disrupted."

The vast majority of the $1.2 trillion price tag (about $1 trillion) would go toward acquisition costs — the money needed to develop, build and deploy the components of the interceptor and tracking layers, as well as conduct research into the system's performance and how to improve it.

"The most expensive component is the space-based interceptor layer, which accounts for about 70 percent of acquisition costs and 60 percent of total costs," the CBO report states.

That layer, in the CBO's notional Golden Dome, consists of 7,800 satellites in a near-polar low Earth orbit — enough spacecraft "to engage a raid of 10 nearly simultaneously launched ICBMs [intercontinental ballistic missiles] during their boost phase. The ability to launch up to 10 ICBMs in rapid succession is considered representative of the capabilities of a regional adversary," the report reads.

A "regional adversary" is one with limited capabilities — North Korea, for example. The report also discusses "peer or near-peer adversaries" — nations close to the United States militarily, such as China and Russia.

The report notes that its overall cost estimate of $1.2 trillion is significantly higher than one given recently by Department of Defense (DoD) officials — $185 billion over the next 10 years.

"That difference suggests either that GDA's objective architecture is more limited than CBO's notional NMD system or that DoD expects significant funding from other accounts to contribute to GDA (or both)," the report states. "For example, procurement of interceptors might be funded directly through the services' missile procurement accounts instead of the GDA fund."

The pricey notional system that CBO came up with would be able to "fully engage" an attack from a regional adversary, according to the report.

"However, the system could be overwhelmed by a full-scale attack mounted by a peer or near-peer adversary," it states. "Furthermore, 'fully engage' is not the same as 'fully defeat' because no defense works perfectly every time."

Complete protection would therefore be incredibly expensive — probably priceless, in both senses of the word.

Two private companies are partnering up to establish a repeatable debris removal service for low Earth orbit.

The U.S. firm Portal Space Systems and Australian startup Paladin Space are working together to establish the commercial Debris Removal as a Service (DRAAS) for removing multiple debris objects during a single mission.

The partnership, which Portal announced on March 19, will see a combining of respective technologies to make the service possible. The platform will be based on Portal's maneuverable, refuelable Starburst spacecraft and will integrate Paladin's Triton payload for imaging, classifying and capturing tumbling debris objects under 1 meter (3 feet) in size.

Space debris experts estimate there are nearly 130 million pieces of junk in orbit, ranging from fragments from explosions and satellite deployments up to huge pieces such as abandoned spacecraft and spent rocket stages. That number alarms many people in the space community and has spurred efforts to start cleaning up our orbital neighborhood.

Some companies have already made serious headway on this effort, showing that debris capture is technically feasible. But Portal and Paladin want to go a few steps further.

"This is about making debris removal operational, not experimental," said Jeff Thornburg, CEO of Portal Space Systems, in a statement. "Satellite data underpins communications, navigation, weather forecasting, and national security. Maintaining that infrastructure requires active debris management."

"Most collision-avoidance activity is driven by small debris," said Harrison Box, CEO of Paladin Space. "Triton is built to remove dozens of those objects in a single mission, which fundamentally changes the cost structure of debris remediation and provides the greatest benefit to satellite operators."

The service has already attracted interest, according to Portal, which states that Starlab Space has signed a letter of intent to integrate the service into future space station operations.

Portal aims to send Starburst-1 into orbit in late 2026 on the SpaceX Transporter-18 rideshare mission, which could pave the way for commercial launches in 2027 onwards. The company also raised $50 million in Series A funding in early April to boost development of its maneuverable spacecraft.

Former NASA Administrator Jim Bridenstine has a new gig.

Jim Bridenstine, who ran the space agency from April 2018 through January 2021, was announced today (May 5) as the new CEO of Quantum Space, a company developing maneuverable spacecraft for use by the U.S. military and commercial operators.

"Jim is a transformational leader and has defined the most significant partnerships and policy initiatives between government and the commercial space industry," Kam Ghaffarian, Quantum Space co-founder and executive chairman, said in a statement. "Jim is poised to lead Quantum during this next phase of growth and as spending on space defense and exploration accelerates."

Maryland-based Quantum Space, which was founded in 2021, aims to become a major player in the commercial and military space arenas with its forthcoming Ranger spacecraft.

Ranger will be able to operate in a variety of environments, from low Earth orbit to Earth-moon space, according to Quantum Space. Its patented propulsion technology, modularity and in-space endurance will give it a leg up on competitors, the company says.

"The Theory of Competitive Endurance requires avoiding operational surprise, denying first mover advantage, and counterspace campaigning. Quantum's Ranger spacecraft is uniquely crafted to deliver on each pillar,” Bridenstine said in the same statement.

"As every domain of warfare is dependent on space, the United States must have ubiquitous space domain awareness, unpredictability for resilience and freedom of action in every orbit," he added. "Quantum's Ranger spacecraft is designed for sustained maneuver for Dynamic Space Operations. It is also modular and refuelable. Any orbit, anytime."

Ranger has not yet left Earth. The company, which raised $80 million during its "Series A" fundraising round, aims to launch the spacecraft's first mission, known as Ranger Prime, in mid-2027.

If all goes well with that test flight, Ranger will move on to operational missions. Those could feature a variety of objectives, from missile defense and space domain awareness to satellite life-extension operations, according to Quantum Space.

Before becoming NASA chief, Bridenstine was a pilot in the U.S. Navy and a member of Congress. He represented Oklahoma's 1st congressional district in the U.S. House of Representatives as a Republican from January 2013 until his confirmation as NASA chief in April 2018, during President Donald Trump's first term.

Bridenstine's time at the agency was quite eventful. For example, he played a key role in the development of the Artemis program of moon exploration, which launched during his tenure. Bridenstine also expanded public-private partnerships in space exploration, via projects such as the Commercial Lunar Payload Services program, which puts NASA science gear on commercial robotic moon landers.

Quantum Space Co-founder Kerry Wisnosky had served as the company's CEO and president. Wisnosky will remain as president, focusing "his leadership and engineering expertise on operations and advancing the company's spacecraft development," the company said in the same statement.

The United States Space Force has created a new program to develop space-based missile interceptors, with the goal of being able to demonstrate their capability within two years.

The U.S. Space Force established the Space-Based Interceptor (SBI) program in order to develop a constellation of spacecraft that can defend the United States against "a new generation of threats" such as hypersonic weapons, neutralizing them while in flight. The program is part of the planned Golden Dome for America defense system announced by President Trump last year. Estimates of the system's price tag range wildly, from the White House's projected $175 billion to as high as $3.6 trillion.

But despite the costs, Space Force says the system is necessary to protect the U.S. in the face of an evolving defense landscape. "Adversary capabilities are advancing rapidly, and our acquisition strategies must move even faster to counter the growing speed and maneuverability of modern missile threats," said Space Force Col. Bryon McClain, in a statement announcing contracts with 12 different companies the program has tapped to help build these interceptors. "With the commitment and collaboration of these industry partners, the Space Force will demonstrate an initial capability in 2028."

Space Force's SBI program aims to develop a constellation of space-based interceptors capable of "boost, midcourse, and glide phase engagements," meaning they can track and intercept advanced hypersonic vehicles during the three distinct stages of their flight: while they are initially accelerating with a rocket motor; as they are flying through the upper atmosphere; or in their final glide phase, during which they can maneuver at high speeds en route to their targets.

Many of the technical details surrounding how Space Force plans to defeat hypersonic weapons from orbit remain unknown. Critics have pointed out that it would require a constellation of potentially tens of thousands of satellites to defend against even 10 missiles, not to mention the fact that no one has ever seen such a capability demonstrated.

But U.S. Space Force Gen. Michael Guetlein, Vice Chief of Space Operations, who was selected to lead the Golden Dome project, has consistently stated that space-based interceptors are physically possible and that the United States and its aerospace contractors have the technologies to make them a reality.

"The most important message I can give to you today is that Golden Dome is real, and it is no longer theoretical," Guetlein said this month, according to Breaking Defense.

"Because we have been protecting the secrets, to protect the nation's investment, to make sure that we don't tip our hand to our adversaries and they get ahead of us … the American public has not had the opportunity to hear what's actually going on, and there's been a lot of confusion," Guetlein added.

Golden Dome draws some inspiration from Israel's Iron Dome, a missile defense system that can intercept rockets and artillery fire. The system also has some parallels with a 1980s missile defense program proposed by President Ronald Reagan, known as the Strategic Defense Initiative, or SDI.

The SDI program was referred to as "Star Wars" due to how much it sounded like science fiction, and never materialized due to its high projected costs, technological barriers, and political resistance to such a plan.

But over four decades later, many spaceflight technologies that once sounded like science fiction are now a reality. As reusable launch vehicles continue to drive launch costs and timelines down, the prospect of a thousands-strong spacecraft constellation is no longer as outlandish as it once was. While we still have no idea what a space-based interceptor would look like or how exactly it would work, U.S. Space Force leaders stress that they're possible.

But plenty of U.S. military programs with multi-billion dollar budgets have received support throughout the government for years only to be canceled. Will Golden Dome go the way of SDI?

Maybe we'll find out in 2028.

Japanese space-sustainability company Astroscale has unveiled plans for a mission it says will be the world's first to inspect multiple defunct satellites in different orbits.

The mission, named In‑situ Space Situational Awareness-Japan 1, or ISSA-J1, is scheduled for launch in 2027 and will inspect two retired Japanese satellites in orbit. It follows the success of the company's Active Debris Removal by Astroscale-Japan (ADRAS-J) mission, which delivered stunning close-up footage of a spent rocket stage in orbit.

The 1,430-pound (650 kilograms) ISSA-J1 spacecraft will use a suite of thrusters and imaging systems to conduct rendezvous and proximity operations, enabling detailed visual inspections of target satellites and helping determine the causes of their failures.

"On-orbit inspection provides critical insight into the condition of satellites that cannot be obtained from the ground," said Nobu Okada, managing director of Astroscale Japan, in a statement. "By inspecting multiple objects in different orbits in a single mission, ISSA-J1 will help demonstrate new capabilities that support satellite operators in understanding spacecraft condition and preparing for future servicing."

The targeted satellites are the Advanced Land Observing Satellite (ALOS), launched in 2006, and the Advanced Earth Observing Satellite‑II (ADEOS‑II), launched in 2002. Once launched, the ISSA-J1 spacecraft will gradually approach ALOS, beginning observations at a distance before moving in for a closer inspection. ISSA-J1 will then transition into another orbit to repeat the process with ADEOS-II.

ALOS is about the size of a bus with a mass of around 8,800 lbs (4,000 kg). The satellite lost power in 2011 but remains in a near-polar orbit with an average altitude of 429 miles (691 kilometers). ADEOS‑II is slightly less massive at 8,150 lbs (3,700 kg) but in a higher near-polar orbit of around 500 miles (806 km) above Earth. The mission ended after less than a year due to the failure of a solar panel.

"Through this sequence, ISSA‑J1 will demonstrate the ability to approach multiple clients in different orbits within a single mission, repeating a cycle of approach, inspection, departure and orbital transition," Astroscale said in a statement.

Astroscale was selected for the on-orbit inspection demonstration mission by the Japan Ministry of Education, Culture, Sports, Science and Technology as part of its Small and Business Innovation Research program. It is part of an effort to advance Japan's space situational awareness and in-orbit servicing capabilities.

The company is also scheduled to launch the ELSA-M orbital debris removal demonstration mission no earlier than 2027 in partnership with Germany's Isar Aerospace. The launch startup is currently preparing for its second-ever launch of its Spectrum launcher at Andøya Spaceport in northern Norway.

COLORADO SPRINGS, Colo.  —  The head of the U.S. Space Force said the United States' ongoing war in Iran shows the service has become a fully "combat credible" force.

Gen. Chance Saltzman, Chief of Space Operations (CSO) for the U.S. Space Force, touted the service's newly evolved combat abilities in an address on Wednesday (April 15) at the Space Foundation's 41st Space Symposium in Colorado Springs. "We aren't just talking about theories or plans anymore. We're talking about real operational combat, space effects and the Guardians who deliver them," Saltzman said.

Saltzman said the U.S. Space Force has demonstrated "combat space power at work" throughout the war in Iran, enabling a variety of support missions and even carrying out electronic warfare attacks. "And it's the men and women of the United States Space Force, both uniformed and civilian, who bring that combat power to bear every day," Saltzman said.

The Chief of Space Operations said that space-based and space-enabled effects have been "critical to mission success" throughout the United States' ongoing war in Iran, citing several specific examples of individual Space Force Guardians and their roles in the conflict.

"On day one of Operation Epic Fury, one of these specialists led the planning and execution of high-tempo space electronic warfare fires for U.S. Central Command, and even when her unit came under attack by indirect fire, she kept her cool, completing emergency maintenance to make sure her weapon systems stayed in the fight," Saltzman said. "That's what it means to be a Guardian in today's Space Force."

The general described another Guardian who had to move an electronic warfare system during Operation Epic Fury in response to changing battlefield priorities. "This was the first time Guardians had ever relocated one of these systems across multiple areas of responsibility on a single deployment," Saltzman added.

Another Guardian was tasked with keeping track of Space Force personnel in U.S. Central Command's area of responsibility while in the line of fire during the conflict, Saltzman told Space Symposium attendees. "Despite enemy fire, power outages, communication blackouts, he kept watch over our most critical asset in theater: our people. That is what it means to be a Guardian in today's Space Force."

The types of "space combat" Saltzman refers to typically involve jamming or disrupting adversary space-based communications or intelligence. This can mean beaming radio interference at satellites overhead in order to jam their communications, or even pointing lasers at the optical sensors on spy satellites in order to blind them. Spoofing GPS signals is another common form of anti-satellite warfare, preventing forces from accurately locating their own assets or using GPS-enabled targeting systems.

But it's not just the United States that is developing and fielding these systems and tactics, Saltzman stressed.

"Our battlefield is filled with hazards like ground-based microwave and laser weapons, all capable of damaging satellites overhead, jammers that can disrupt GPS communications satellites, and even threats of nuclear-capable anti-satellite weapons on orbit, and that's just what we face today," Saltzman said.

That's why the service needs to adapt a "generational shift" in the way it develops and fields new technologies, the CSO said. That call has been a recurring theme of Saltzman's addresses at Space Symposium in recent years, as well as those of other U.S. military leaders.

But Saltzman stressed that, as recent U.S. military conflicts in Venezuela and Iran show, the Space Force will be prepared thanks to the flexibility and resilience of what he has consistently described as its most valuable asset: its personnel.

"No matter what threats we face today or tomorrow or in 2040, the Space Force will be there, lethal, a predator in the fight," he said.

SpaceX began and ended the day with Starlink launches.

The company sent two Falcon 9 rockets soaring, first from Florida before sunrise on Tuesday (April 14), and then from California after sunset the same day (by local time zone). Both launches were successful, according to SpaceX.

First up, were 29 of the broadband internet relay units (Starlink group 10-24) at 5:23 a.m. EDT (0923 GMT) from Space Launch Complex 40 at Cape Canaveral Space Force Station in Florida. Then, about 19 hours later at 9:29 p.m. PDT (12:29 a.m. EDT or 0429 GMT on April 15), 25 more Starlink satellites (group 17-27) lifted off from Space Launch Complex 4 East at Vandenberg Space Force Base in southern California.

About an hour after each launch, the Falcon 9 upper stage deployed its cargo, sending the satellites on track to join the SpaceX low Earth orbit megaconstellation.

Both missions' Falcon 9 rocket first stages made it back to Earth to be reissued. Booster B1080 completed its 26th flight by landing on the droneship "Just Read the Instructions" based in the Atlantic Ocean. Then Booster 1082 touched down on "Of Course I Still Love You" stationed in the Pacific Ocean, raising its reuse tally to 21 flights.

After the doubleheader, SpaceX's Starlink network totaled more than 10,200 satellites, according to tracker Jonathan McDowell. The Vandeberg launch was SpaceX's 46th of the year out of 629 Falcon 9 missions 2010.

The Earth-observation company Planet Labs is withholding its satellite imagery of Iran indefinitely.

In response to a request from the U.S. government, Planet Labs made a decision not to share photos of Iran as well as the larger conflict region in the Middle East indefinitely, the California company shared in an April 5 statement emailed to customers. The decision follows a 14-day delay in imagery of the Middle East that the company initiated last month in an effort to prevent attacks on the U.S. and its allies, according to Reuters.

Not everyone is a fan of the decision.

"It seems that it's a way to impact the American public's ability to understand what's happening as opposed to having an impact on the battlefield," Victoria Samson, chief director of space security and stability for the nonprofit Secure World Foundation, told Space.com.

Planet Labs operates a large fleet of satellites in low Earth orbit that capture images of our planet, which are then sold to government agencies, or companiesWhile the U.S. government is one of the company's largest customers, it is not the only one, and Planet Labs has a history of working internationally. The company even describes itself as being a "mission-led public benefit corporation whose founding purpose is to use space to help life on Earth."

Indeed, satellite imagery like that captured by Planet Labs is used for a variety of purposes, not just defense planning.

"It's unfortunate given the extent that their work is used, not just by militaries but by other actors trying to follow refugee flow and seeing where there's damage, and for agricultural reasons," Samson said, adding that withholding images sparks concerns from a public safety perspective.

In addition to the many non-military purposes that satellite imagery serves, it also allows the public to see with their own eyes what is happening in a given region and the true extent of damages inflicted during wartime, as well as the consequences of other actions.

Samson cited one specific instance from earlier in the war in which satellite imagery — specifically, photos from Planet Labs — played an important role. In early March, there was initial confusion about the extent of the strikes that took place on an Iranian school. Satellite imagery from Planet Labs revealed the extent of the damage and shed light on how many lives were lost in the attack.

In its history, Planet Labs has previously freely shared important imagery. For instance, the company has released photos that have helped first responders deal with natural disasters, as well as imagery revealing details about Russia's ongoing invasion of Ukraine.

This is not the first time that satellite imagery has been restricted from public view. For example, photos of sensitive military locations or government facilities are often blurred on applications like Google Maps. However, Samson said, Planet Labs' decision appears to be the first time that such a large region has been restricted from satellite view.

"It probably will start a precedent that I don't think will be good for overall transparency," she said.

Planet Labs also shared in the April 5 statement that it will be holding back all imagery dating back to March 9, and that this withholding will continue until the conflict has ended. There is one small exception to this ban, however. Planet Labs will release images on a case-by-case basis if an urgent need presents itself, the company shared in the statement. These decisions follow the official start of the war, which began on Feb. 28 when the U.S. and Israel attacked Iran.

Planet Labs is among a variety of companies that provide satellite imaging services, and some of the others may be making similar decisions. For example, the companyVantor, formerly known as Maxar Intelligence, told Space.com that it has put "controls in place over parts of the Middle East," though the company added that these controls "were not put in place in response to a specific U.S. government request." At this time, it is unclear what other companies are also restricting access to satellite imagery.

Space.com reached out to Planet Labs for comment, but the company did not respond before the publication deadline.

Artificial lights at night brightened up planet Earth by 16% between 2014 and 2022, a new study using satellite images has revealed.

But some areas, including those struck by war and natural disasters, or those in countries with effective light pollution and energy-saving policies in place, are bucking the trend.

From space, Earth at night is a magnificent sight — a darkened sphere lined and dotted by blueish and golden lights revealing outlines of countries and continents. It has not always looked like that. For our ancestors, that twinkling ball would have been completely dark. Artificial lights at night reveal the progress of civilization as new settlements spring up and electric grids expand, bringing the comforts of modern life. But constant artificial light has also become a problem, affecting sleep quality, disrupting plant and animal biorhythms and obstructing our views of the cosmos.

The new study, by an international team of researchers. found that Earth is getting brighter overall. But there are caveats: In many areas, lights have actually been extinguished by war and natural disasters, or dimmed by effective energy-saving policies. In fact, Zhe Zhu, the study's lead author, said that, despite the overall brightening visible in the satellite images, the world's dimming areas are actually increasing in size at an accelerating pace.

"We found that the Earth is not gradually brightening, it is flickering," said Zhu, an associate professor of remote sensing at the University of Connecticut. "The brightening is mostly driven by developing countries like India, China and parts of Africa. But we also see the areas of dimming increasing every year. Some of that is due to sudden events like wars and natural disasters, but we also see a huge area of dimming in Europe, where they put policies in place. The U.S. is still mostly increasing."

A dramatic decline in night-time artificial light was observed, for example, in Ukraine following the Russian invasion, which began in February 2022. France, a developed western European country, dimmed by a staggering 33% thanks to new policies.

Zhe said the study is the first to reveal the trends in artificial light use with a level of temporal detail that distinguishes individual events and regional trends. The researchers could thus see in the data the rollouts of the COVID pandemic lockdowns across the world and monitor phases of armed conflicts.

"You can see almost in real time when there is a war happening," said Zhe. "In Palestine, you could see many dips — ups and downs — every time the war flares up. You can also see disasters, such as major hurricane impacts in Puerto Rico, which basically wipe out electricity for a long time."

The researchers used data from NASA's Black Marble tool, which uses special algorithms to process measurements from the Visible Infrared Imaging Radiometer Suite (VIIRS). The VIIRS instrument flies on both the Suomi National Polar-orbiting Partnership (NPP) satellite, a joint effort of NASA and the U.S. National Oceanic and Atmospheric Administration, and its predecessor, NOAA-20. VIIRS captures a wide range of light signatures, from ultraviolet to infrared light, revealing the nighttime glow of the planet.

The algorithms, Zhu explained, filter out unwanted noise such as moonlight reflections, auroral light, the shadowing by clouds and vegetation, and even differences caused by the viewing angle of the satellite during different passes.

The brightness increases reported in this study, however, may be somewhat skewed, as the satellite sensors feeding the NASA Black Marble tool are not sensitive to the blue-tinged light emitted by most traditional LED lights, which dominate the lighting technology of today, Zhe said.

A 2023 study, based on more than 50,000 observer reports from all over the world, concluded that the perceived night sky brightness in inhabited locations worldwide had been increasing at a mind-boggling rate of nearly 10% per year in the past decade. This brightness increase is effectively erasing stars from the night sky, forcing skywatchers and professional astronomers to retreat into ever more remote locations. The incessant glow, which prevents true darkness from setting in even in the dead of night, also has profound effects on human, plant and animal health, disrupting sleep and natural growth cycles.

"Human vision at night is most sensitive towards shorter wavelength (blue) light and has little sensitivity to near infrared light, but the VIIRS has no sensitivity to light below 500 nm (i.e. blue light), and can easily see infrared light from high-pressure sodium lamps," Christopher Kyba, a professor of night-time light remote sensing at Ruhr University Bochum in Germany and one of the co-authors of the paper, told Space.com in an email. "So, when a city converts a street from high-pressure sodium to white LED, then a person would say it got brighter, but the satellite would say it got darker."

Kyba also led the 2023 observer study.

Zhe says the brightening isn't just a doom-and-gloom signal for skywatchers. In many areas, especially underdeveloped regions of Africa and Asia, the lights mean improved economic prosperity.

"From the economic perspective, brightening can be a good thing," he said. "It means more activity, people having access to power where they previously didn't have it."

The study was published in the journal Nature on Wednesday (April 8).

Late on July 29, 2025, the Earth's crust off of Russia's Kamchatka Peninsula ruptured. Deep beneath the Pacific, along a subduction zone where one tectonic plate dives beneath another, a strain that had built up over decades was released in seconds. That rupture, a powerful magnitude 8.8 earthquake, displaced the seafloor and the water column above it, resulting in a tsunami. The tsunami radiated outward across the Pacific, racing across the open ocean as fast as an airplane and eventually surging onto the shore, reaching heights exceeding 55 feet (17 meters).

Scientists have long understood this chain reaction, but a detailed look at how an earthquake-tsunami event unfolds at the source — a subduction-zone trench — has remained difficult to achieve. There aren't enough tsunami-monitoring sensors near the trenches to get a clear look.

The key, it turns out, is satellites.

Rather than relying on purpose-built tsunami detection systems alone, researchers are increasingly turning to existing satellite missions and finding novel ways to use them. NASA and the French Space Agency's Surface Water and Ocean Topography (SWOT) satellite, originally designed to study global water levels and ocean circulation, is now proving to be a powerful tool for tsunami science as well.

A team of researchers led by Ignacio Sepúlveda of San Diego State University, used SWOT to observe the Kamchatka tsunami, and their resulting work gives an unusually clear view into tsunamigenesis, or the birth of a tsunami. Using satellite data, tsunami and earthquake researchers can better model — and hopefully better forecast — these extreme ocean events.

Sepúlveda, who leads the SDSU Coastal Engineering Lab, has long used satellites to study ocean events. Because previous tsunami research tapped into SWOT for observations, Sepúlveda and his researchers knew they could use the satellite to see the Kamchatka event — and they had something of a lucky break.

Just 70 minutes after the earthquake, SWOT passed over the Pacific roughly 375 miles (600 km) from the epicenter, imaging in high detail not only the tsunami's leading wave, but also a train of smaller waves trailing behind it.

As the team attempted to simulate the 2025 Kamchatka event, they ran into a problem. "When we reproduced the tsunami using our simplest model, the long-wave model that everybody uses extensively, we saw that the model was not reproducing all the properties that were observed by SWOT," Sepúlveda told Space.com.

The issue was those trailing waves, called dispersive waves. The long-wave model simply doesn't account for them, since dispersive waves are not easily observed with existing technology.

Traditional tsunami monitoring relies heavily on Deep-ocean Assessment and Reporting of Tsunamis (DART) buoys, which measure pressure changes at the seafloor. While crucial for tsunami warnings, these sensors are limited in what they can detect. DART buoys provide measurements at single points, so it's impossible to "see" the full structure of a tsunami.

By contrast, SWOT offers a wide, two-dimensional view of the ocean surface, capturing wave direction, spacing, and curvature with centimeter-level precision. "Here, we have extra information coming from the satellite that we are not commonly getting from other types of instruments," said Sepúlveda. "With that 2D image, you are able to characterize very well what happened with the tsunami's leading wave and the trailing waves."

Sepúlveda and his team realized they needed to use a different model — the more sophisticated Boussinesq-type model — to correctly reproduce the SWOT observations of the Kamchatka tsunami. That broader perspective allowed researchers to identify a key insight: the dispersive waves carry information about where the tsunami originated. Now, the team was able to pinpoint tsunamigenesis to within about six miles (10 km) of the trench, marking such a close-up view for the first time ever.

The findings mark a turning point in tsunami science. For the first time, scientists have direct, high-resolution, two-dimensional observations linking a tsunami's structure in the open ocean to the details of the earthquake that created it. "In the long term, we will improve our models because we will start to know much better what is going on in that near-trench area," said Sepúlveda.

By improving how scientists model tsunami generation — particularly the elusive near-trench processes, which produce some of the most dangerous tsunamis — these observations can help refine forecasting systems. Better models mean more accurate predictions of wave height, timing, and impact at coastlines. And when used in conjunction with other monitoring tools like DART buoys, that could translate into faster warnings, better evacuations and lives saved when the next major tsunami strikes.

Breaking up is never easy. That's definitely the case for this SpaceX Starlink spacecraft, which underwent a "fragmentation event" on March 29, 2026.

Today's image shows the spacecraft weeks prior to it breaking apart.

What is it?

SpaceX described the fragmentation event on its Starlink X feed, writing:

"On Sunday, March 29, Starlink satellite 34343 experienced an anomaly on-orbit, resulting in loss of communications with the satellite at ~560 km above Earth. Latest analysis shows the event poses no new risk to the @Space_Station, its crew, or to the upcoming launch of NASA’s Artemis II mission. We will continue to monitor the satellite along with any trackable debris and coordinate with @NASA and the @USSpaceForce.

"The event also posed no new risk to this morning's Transporter-16 mission, which was designed to avoid Starlink with payload deploys well above or well below the constellation. The SpaceX and Starlink teams are actively working to determine [the] root cause and will rapidly implement any necessary corrective actions."

Why is it amazing?

Today's image of Starlink satellite 34343 was captured by HEO Robotics on Feb. 14, 2026. HEO posted the image to X

HEO is now working toward imaging the current state of the SpaceX unit after its fragmentation.

SpaceX launched than 100 satellites to orbit from California early Monday morning (March 30).

A Falcon 9 rocket lifted off from Vandenberg Space Force Base in California on Monday at 6:20 a.m. EDT (1020 GMT; 3:20 a.m. local California time).

Transporter-16 lofted 119 payloads, "including cubesats, microsats, hosted payloads, a reentry vehicle, and orbital transfer vehicles carrying eight of those payloads to be deployed at a later time," SpaceX wrote in a mission description.

As its name suggests, Transporter-16 was the 16th mission of SpaceX's Transporter rideshare series. The company also operates another rideshare program called Bandwagon, which has four launches under its belt so far.

Together, these two programs have lofted a total of more than 1,600 payloads to orbit — including 143 on Transporter-1 in January 2021, which still holds the single-launch record.

The Falcon 9's first stage landed about 8.5 minutes after launch on the SpaceX droneship "Of Course I Still Love You," which was stationed in the Pacific Ocean. It was the 12th launch and landing for this particular booster, according to the mission description.

The rocket's upper stage, meanwhile, hauled the 119 payloads to low Earth orbit, where they were deployed starting about 55 minutes after liftoff.

Astronomers are up in arms, protesting against a proposed constellation of tens of thousands of orbiting mirrors intended to reflect light onto ground-based solar power plants and SpaceX's envisioned one million orbiting data centers.

The projects, which have been put forward to the U.S. Federal Communications Commission (FCC) for approval, would destroy the night sky as we know it and obscure the views of astronomical telescopes all over the world, hampering scientific progress, according to experts.

"This is really intolerable," Robert Massey, the deputy executive director at the British Royal Astronomical Society (RAS), told Space.com. "It's absolutely the destruction of a central part of human heritage."

RAS, the oldest astronomical society in the world, has joined the growing army of research institutions filing objections to the FCC against the proposals by SpaceX and California-based startup Reflect Orbital.

SpaceX announced its plans to launch one million data centers to space in January. The company's founder and CEO, Elon Musk, said on X at that time that moving power-hungry computing infrastructure into space is necessary to fully unleash the powers of AI. Reflect Orbital, founded by former SpaceX intern Ben Nowack, has ambitions to launch 50,000 orbiting mirrors into space, each one about 180 feet (55 meters) wide.

If those plans were to pass, the sky as humankind has known it for millions of years would change beyond recognition.

"If you have a direct view of this, it would be several times as bright as the full moon," said Massey. "That's extraordinarily bright."

Even if seen at an angle, the orbiting mirror would be as bright as Venus, the brightest object in the night sky after the moon.

"Imagine a stream of satellites with that kind of magnitude crossing the sky," said Massey. "It would absolutely transform our view of the sky."

Add to that the million proposed SpaceX data centers, which, although dimmer, would also be visible to the naked eye. Due to the vast size of these planned constellations, there would be thousands of shining dots as bright as stars criss-crossing the firmament at any given moment.

Massey estimates the sky would become up to three times brighter as a result of the vast quantity of Reflect Orbital's sun-reflecting mirrors. That brightening would affect the entire planet, including remote locations that are now considered dark sky sanctuaries, where astronomers build their sky-observing machines.

The European Southern Observatory (ESO), an international astronomy research organization that operates some of the world's largest telescopes, has also filed objections against the two proposals.

ESO astronomer Olivier Hainaut told Space.com that the Very Large Telescope in Chile would lose up to 10% of pixels in every image if SpaceX's one million orbiting data centers were to materialize. That number could rise to up to 30% for some kinds of observations.

"That's a huge loss," Hainaut said. "We keep our technical losses below 3%, and the total weather losses are about 10%."

The overall increase in sky brightness caused by the Reflect Orbital mirror constellation would mean astronomers would have to triple exposure times when taking images.

"We wouldn't be able to observe our faint targets anymore," Hainaut said. "It would be disastrous."

Fabio Felchi, a light pollution researcher at Istituto Superiore "Enrico Fermi"​ Mantova in Italy, told Space.com that "the only option we have to save the starry night as it was for billions of years is to put a limit on the total number of satellites in orbit."

He added that a safe limit has already been passed and called for "a red-line policy on this, as there is for most other pollutants."

Noelia Noel, an astrophysicist at the University of Surrey in the U.K., said that the two proposals "mark a critical moment in how we manage humanity's presence in space."

"While innovation in satellite technology brings clear societal benefits, scaling to hundreds of thousands or even millions of bright objects — or deliberately illuminating the Earth from orbit — risks fundamentally altering the night sky," she said. "This would have profound consequences not only for astronomy but also for ecosystems, our cultural heritage, and our collective relationship with the cosmos."

Some worry that the FCC is in favor of those proposals, as it's fast-tracking their evaluation without expecting the companies to carry out environmental impact assessments, astronomer and dark sky consultant John Barentine previously told Space.com.

"The presumption now is that the application should be approved and that it should be up to the people who might object to prove that there's a problem of some kind," said Barentine. "The fact that they have fast-tracked this application, which has potentially tremendous effects not only for astronomy but for the environment too, and to do so without engaging in a full environmental review, is worrisome."

AI systems could soon be able to hijack satellites in orbit and cause them to collide with other spacecraft, potentially triggering a dangerous cascade of smash-ups that could render the environment around Earth unsafe for years, according to experts.

Cyber security researchers are already using AI to identify so-called zero-day vulnerabilities — yet undiscovered security holes in code — to alert operators and help them patch the problems before hackers could exploit them. But attackers, too, can take advantage of those advanced systems to find those holes more quickly.

Speaking exclusively to Space.com, researchers at the CR14 cybersecurity center in Estonia said that advances in AI could make it possible for an AI-led attack to wreak havoc in orbit in as little as two years. The emergence of so-called agentic AI — autonomous systems powered by Large Language Models (LLMs) such as OpenAI's ChatGPT or Google's Gemini, which can independently plan action and execute tasks to achieve set goals — is especially worrying, Kristjan Keskküla, CR14 Head of Space Cyber Range, told Space.com. "AI is developing quite quickly right now," Keskküla told Space.com. "The real problem now is that AI can act, take decisions, analyze things and come up with new exploits."

Clémence Poirier, a cyber security researcher at the ETH Zurich University in Switzerland, told Space.com that although no known AI-enabled cyberattack on space systems has taken place so far, state-funded hackers are known to have used LLMs to research space systems vulnerabilities in the past.

"In 2024, OpenAI and Microsoft revealed that Russian threat actor Fancy Bear used LLMs to search about satellite communications, radar systems and other space technologies to support information gathering in view of potential attacks," Poirier said in an email. "AI definitely helps threat actors in the reconnaissance and intelligence gathering phase of an attack. Threat actors can find known vulnerabilities in space systems with LLMs. The time to exploit known vulnerabilities has been immensely reduced because of AI."

Andrzej Olchawa, a space cybersecurity engineer and researcher at VisionSpace told Space.com that "LLMs have drastically lowered the barrier to understanding spacecraft operations and communication protocols."

While in the past, developing an understanding of how space systems operate required extensive study, today, LLMs enable "adversaries with no prior knowledge of the space industry to process documentation and open-source software," and cause real harm.

"Interpreting telemetry and telecommand structures once required extensive study of thousands of technical pages," Olchawa said. "Today, one can simply instruct an LLM to generate parsers and provide mission-specific context with minimal expertise."

What is worse, the accelerated AI threat has emerged just as the space sector began to wake up to the cybersecurity risks, which it had ignored for decades. Many older satellites that are still in orbit and operational have no cyber protection systems in place, said Keskküla, making them a low-hanging fruit for a possible attack.

Many possible ways of attacking a spacecraft exist, including jamming and spoofing of the communication links between the satellites and ground control either from Earth or from space. But the experts are especially worried that hackers could find ways to completely hijack satellites and turn them into orbital anti-satellite weapons.

"They could make them collide with other satellites and cause havoc," Keskküla said. "In the last about three years, we have sent up 8,000 satellites. It's a huge number of satellites, and the constellations are growing. You only need to affect one satellite's actions to cause problems."

The researchers worry that one such deliberate space crash could create thousands of fragments in the heavily used low Earth orbit — the region of space at altitudes up to 1,200 miles (2,000 kilometers) where most satellites reside — which could make the orbital environment unsafe for years.

CR14 is one of the largest cybersecurity research and training centers in the world, and, thanks to Estonia's proximity to Russia, has been at the forefront of Europe's cyber defence against escalating Russian attacks for years.

"During our exercises, we simulate these kinds of attacks in a virtual environment using digital twins," Keskküla said. "We have attackers, and we have defenders, one group trying to penetrate the system and do bad things, the other trying to protect it."

Martin Hanson, CR14's head of communication, added that the quantity and sophistication of cyberattacks is bound to keep rising. Ukraine, he said, experiences "thousands of cyberattacks" on critical infrastructure every day, including on power grids, banks and satellite communication systems.

In Europe, he added, the number of phishing attacks has grown by 500% over the past few years, and the sophistication of those attempts to steal sensitive information by means of social engineering is bound to grow thanks to the use of AI.

"AI will make these attacks more targeted," he said. "They will gather more information about you, and they will try to copy your friends and coworkers. It's getting more sophisticated. "

SpaceX's plan to launch one million orbiting data centers to space worries astronomers,who say the satellite streaks caused by the proposed constellation would severely impair observations.

Just as astronomers began to learn how to coexist with broadband megaconstellations in low Earth orbit (LEO), such as SpaceX's Starlink, a new threat has emerged, causing significant concerns. Elon Musk's envisioned constellation of one million orbital data centers would result in possibly tens of thousands of moving objects as bright as stars that are visible in the night sky at any given moment, even to the naked eye, according to astronomer and dark sky consultant John Barentine.

Barentine spoke to Space.com on behalf of a group of astronomers who are raising objections against SpaceX's application to launch the constellation, which the company filed with the U.S. Federal Communications Commission (FCC) on Jan. 30.

Starlink currently consists of around 10,000 satellites. Those spacecraft are visible to the naked eye only shortly after launch, because they dim as they raise their orbital altitude. The Starlinks still leave streaks in telescope images, but SpaceX has, after consultations with the astronomy community, managed to reduce the satellites' brightness by using less reflective materials and tilting reflective components like solar panels away from Earth. The brightness of newer Starlink satellites dropped to just above the limit recommended by the International Astronomical Union to prevent interference with astronomical observations. SpaceX's new data-center plan, however, threatens to thwart this progress, according to Barentine.

"It really feels like it's undermining what we have achieved in the last few years, which wasn't ideal for astronomy, but was a far cry from what we feared in 2019 when the Starlink program began," he told Space.com. "We felt we were heading in the right direction that was reasonably sustainable. And this feels like a complete reversal of that."

According to some estimates, each of the orbiting data centers could be up to 330 feet (100 meters) long, circling Earth at altitudes between 310 miles and 1,243 miles (500 to 2000 kilometers) pole to pole with a constant exposure to sunlight.

"The other constellations that we have dealt with so far are mostly at lower altitudes and in lower-inclination orbits," Barentine said. "That means the satellites spend most of their time in Earth's shadow. We really don't see them very much in the middle of the night, or they are not that bright. But the data centers will be in high-inclination orbits and will be fully illuminated by sunlight even as seen from the ground at midnight."

Barentine described the proposal as a "vastly different prospect" compared to all other existing and planned constellations.

"This is a challenge unlike any we have encountered thus far in this new era of commercial space," he said.

The development comes just as the astronomical world brings online some of the most powerful sky-observing machines of all time, designed to push the limits of the human understanding of the universe. These big ground-based scopes, including the $10 billion Vera Rubin Observatory, opened last year, or the $2 billion Extremely Large Telescope currently under construction in Chile, will have their observations severely obstructed by those satellites.

"We could schedule our observations so that we aren't looking in the direction of the satellite when it's passing or close the shutter in front of our cameras and reopen it later on," said Barentine. "But at some point, the amount of time the shutter is closed starts degrading your observations. And I worry that, with more than a million objects, the shutter would be closed more than it would be open."

In addition, Barentine and his colleagues estimate that, with the expected rate of replacement of the constellation's satellites with newer technology, one old spacecraft would be burning up in Earth's atmosphere every three minutes. This mass incineration of metal would result in a steep increase in concentrations of potentially dangerous pollutants such as aluminum oxide and lithium in the upper atmosphere, which could lead to ozone depletion and temperature changes.

Currently, about three old satellites or used rocket bodies perish in the atmosphere every day. Further air pollution would come from the frequent rocket launches needed to deploy and maintain the constellation. The project would also increase the risk of space debris strikes on Earth, the astronomers say.

The researchers are even more concerned about the development because the FCC put the application on a fast-track path, meaning SpaceX won't need to conduct an environmental impact assessment of the project.

Barentine explained that, while in the past applicants had to prove that a development would not cause significant environmental harm, the fast-track process means it is now up to those objecting to a development to conduct those frequently time-consuming analyses to prove their case.

"The presumption now is that the application should be approved and that it should be up to the people who might object to prove that there's a problem of some kind," said Barentine. "The fact that they have fast-tracked this application, which has potentially tremendous effects not only for astronomy but for the environment too, and to do so without engaging in a full environmental review, is worrisome."

The objectors had only until March 6 to submit their documentation, putting further pressure on the astronomers, according to Barentine.

SpaceX didn't respond to Space.com's request for comment.

A big NASA satellite crashed back to Earth on Wednesday morning (March 11) after nearly 14 years in orbit.

The spacecraft in question is the 1,323-pound (600-kilogram) Van Allen Probe A, which launched in August 2012 along with its twin, Van Allen Probe B, to study the radiation belts around Earth for which they're named.

Both spacecraft were deactivated in 2019, and Van Allen Probe A has now given up the ghost.

"The U.S. Space Force confirmed the Van Allen Probe spacecraft reentered the atmosphere at 6:37 a.m. EDT [1037 GMT] on Wednesday over the eastern Pacific Ocean region, at approximately 2 degrees south latitude and 255.3 degrees east longitude," a NASA spokesperson said in an emailed statement on Wednesday evening.

"NASA expected most of the spacecraft to burn up as it traveled through the atmosphere, but some components may have survived reentry," the spokesperson added.

The reentry date and time were in line with predictions: On Monday afternoon (March 9), the Space Force forecast that the satellite would reenter Earth's atmosphere on Tuesday (March 10) at 7:45 p.m. EDT (2345 GMT), plus or minus 24 hours.

NASA officials had previously said that there's just a 1-in-4,200 chance that Van Allen Probe A will hurt anyone during its reentry. That low risk of injury — about 0.02% — takes into account the fact that water covers about 70% of Earth's surface. So, any parts that survive reentry were likely to splash down in the open ocean, not land in or around a city.

The Van Allen Probes — which were originally called the Radiation Belt Storm Probes — launched to a highly elliptical orbit, which took them as far away from Earth as 18,900 miles (30,415 kilometers) and brought them as close as 384 miles (618 km).

The mission was supposed to last just two years, but the spacecraft managed to continue operating until July 2019 (Probe B) and October 2019 (Probe A). They gathered data that scientists and mission planners analyze to this day.

"By reviewing archived data from the mission, scientists study the radiation belts surrounding Earth, which are key to predicting how solar activity impacts satellites, astronauts, and even systems on Earth such as communications, navigation and power grids," NASA officials said in a statement this week. "By observing these dynamic regions, the Van Allen Probes contributed to improving forecasts of space weather events and their potential consequences."

Both probes were expected to stay up in Earth orbit until 2034. However, the sun has been unexpectedly active in recent years, causing our planet's atmosphere to expand and frictional drag on orbiting satellites to increase.

Such effects have likely shortened Van Allen Probe B's time in space as well, but less dramatically than its twin's. Probe B isn't expected to reenter before 2030, according to NASA.

Editor's note: This story was updated at 6:10 p.m. ET on March 11 with news of Van Allen Probe A's reentry.

Europe's Copernicus Sentinel-2 satellite mission captured this stunning image of south-central Morocco, showing the the city of Ouarzazate, the Anti-Atlas Mountains, and the Ouarzazate solar power station.

What is it?

This false-color image of south-central Morocco was taken by the Copernicus Sentinel-2 mission and released on the European Space Agency website on Feb 20, 2026.

The image shows the northern edge of the Anti-Atlas Mountains, which sit just below the city of Ouarzazate. The upper half of the photo is dominated by a vast desert landscape, which is home to the Ouarzazate solar power station.

We can see striking contrasts from the colored regions, with huge areas of vegetation shown in bright red, and the El Mansour Eddahbi Reservoir, which is shown as a deep, dark blue. The image was taken in January 2026, during the rainy season, which means we can also clearly see the rivers and tributaries that feed into the reservoir.

Why is it special?

The Copernicus Sentinel-2 mission, which captured these images, comprises three satellites that sit in low Earth orbit. The Sentinel-2A and Sentinel-2B satellites launched in June 2015 and March 2017, respectively, and Sentinel-2C joined them in orbit in 2024.

Since this is a false-color image that has been processed using Sentinel-2’s near-infrared channel, vegetation appears with a striking red hue. This is because plants reflect more near-infrared than green light, resulting in a bright red coloration.

We can also see the staggering size of the Ouarzazate solar power station, also called Noor (Arabic for "light") Power Station. This mammoth site covers over 7,400 acres (3,000 hectares) — almost as large as the city itself — and is the world's largest concentrated solar power facility.

PHOENIX — In June of 2025, we were greeted with a set of space images so special that one scientist even deemed them worthy of the title "astro-cinematography." Indeed, they were unbelievable, dotted with TV-static-like dots representing millions of galaxies, printed with nebulas resembling watercolor canvases, and bursting with data about some of the farthest cliffs in our observable universe.

These were the first portraits to come out of the Vera C. Rubin Observatory, humanity's magical new cosmic watchkeeper fitted with the world's largest digital camera and a telescope with an enormous field of view. Rubin has the ability to thoroughly image the night sky over and over again from its vantage point atop Cerro Pachón in Chile, and with unprecedented efficiency at that. This is an instrument anticipated to revolutionize astronomy and reveal things about the universe we won't be able to fathom until we find them.

"We're going to actually create more data than all optical astronomy has ever had in the first year of our decade of operations, which absolutely blows my mind," Meredith Rawls, an astronomer working on the observatory, said during January's American Astronomical Society meeting.

It all sounds like a dream — but a wakeup call may be looming. An Earth-based telescope approaching the limits of modern technological power is unfortunately forced to contend with another kind of scientific advancement happening in space: the exponential rise of satellites in Earth orbit.

As of writing this article, there are about 14,000 satellites orbiting our planet — nearly 10,000 of which belong to SpaceX — and the number is going to increase aggressively as commercial interests in this realm continue to grow. Blue Origin and Eutelsat's OneWeb, for instance, are following SpaceX's example, as are several Chinese companies, and smaller startups are readying their own endeavors. SpaceX has actually recently floated the idea of a data center in our planet's orbit, which would involve putting something like a million more satellites up there.

Priceless Rubin images could therefore be tainted by commercial satellite interference, or "streaks," as astronomers say.

Why satellite streaks are a big problem

You may have heard about this issue before, as satellites are already well-documented to interfere with astronomy imaging. You can even see a streak right here in this relatively inconsequential image from the Gemini North Telescope, and there are quite a few studies written about why we need to be worried about megaconstellations populating Earth orbit in general.

"Astrophotography is a valuable educational tool for raising awareness and interest in the natural world," Federica Bianco, a scientist with the University of Delaware, said during the conference. "The night sky environment is often culturally significant, and dark sky tourism has been recognized as an important factor in sustainable development of rural and remote communities."

Just this month, physicians and scientists from Northwestern University announced they're worried about satellites in Earth orbit disrupting our sleep patterns.

"They change the night sky," Rawls said. "Turns out, telescopes are not the only things that look up."

But even though satellite interference with science isn't a new conundrum, the existence of Rubin brings the consequences into clearer focus.

"The same features that made Rubin really amazing for discovery are the same features that also make it vulnerable," Rawls said. "Its wide field of view; its very sensitive camera; the fact that it can scan the whole southern sky every three nights — it's going to see a bunch of satellites."

"If all you're going for is a pretty picture, fine — you can Photoshop out the streaks," she said. "But trying to get the science out of that is a little bit trickier, because you're introducing systematic errors in a way that's actually very, very tricky to account for."

The depth of the issue

At this year's AAS conference in Phoenix, a cadre of scientists affiliated with Rubin spoke about different ways satellite streaks could affect the telescope's discoveries. The goal? Find a solution before things get out of hand.

The room was absolutely filled, speaking to the urgency of the topic.

One effort, perhaps the most obvious one, revolves around scientists working with satellite operators and builders to help them create spacecraft that mitigate interference.

For instance, the International Astronomical Union (IAU) recommends keeping satellite brightness at magnitude seven or lower. If you're unfamiliar, in this centuries-old system, smaller numbers indicate a higher brightness than larger numbers. So, magnitude zero is 100 times brighter than magnitude five, and the full moon has a magnitude of around -12.6, while the sun lies around -27.

"Above this [magnitude 7] limit means that the satellite will most likely saturate the pixels, making it impossible to recover the data underneath the satellite," Jeremy Tregloan-Reed, a member of the IAU Centre for the Protection of the Dark and Quiet Sky from Satellite Constellation Interference, previously told Space.com.

Rawls said that, when a satellite's brightness is around four or five, it can cause considerable interference — especially when many spacecraft with this brightness level are present in an image. "You start to get this crosstalk effect," she said, "where you get these extra streaks kind of parallel to the main streak."

"The whole object, really, for [Rubin's mission], is to discover something really new, something that's going to blow our minds, not something that's been known for decades before — a new class of object, a new kind of thing — and discovering the unexpected, the needle in that haystack is made much more difficult by having a whole lot of foreground systematic errors," said Anthony Tyson of the University of California, Davis.

The responsibility of satellite companies

"There is a possibility that we may be able to coordinate with some of the operations' brightest satellites to actually have them reorient their hardware or adjust their attitude, as they say in satellite speak, so they would not glint as brightly where Rubin happens to be pointing at night," Rawls suggested.

Some headway has been made on that front, but historically, there has been a bit of friction. All companies haven't been adhering to the magnitude guidelines, for instance. Most notably, the BlueWalker 3 satellite, operated by the Texas company AST SpaceMobile, was over 400 times brighter than the recommended magnitude seven.

More recently, Connie Walker of the National Science Foundation's NOIRLab said the Rubin team has been in contact with about 16 different satellite companies. "Some have been more forthcoming in talking with us than others," she told Space.com. She also said, however, that she'd just been speaking at the conference with the company Reflect Orbital, which appears to be receptive.

This is a great sign, seeing as Reflect Orbital's ultimate hope is to put over 50,000 satellites in Earth orbit by the year 2035. Why? Well, to place mirrors around our planet that can reflect sunlight, so that this sunlight can be sold as a service to light up different parts of Earth on demand. "That's going to be challenging for astronomy," Walker said.

"It's essential for satellite operators to publicly share where they are and, ideally, how they're oriented, so that we can understand when it's going to be a problem for us," Rawls said.

Walker also explained that SpaceX has given the team permission to test satellite reflectiveness with the materials the company uses to make its satellite constellations. "They give us an old one, and we can do some modeling on that."

But at the end of the day, despite satellite companies being open to conversation at times, "it's not a full-scale charge on that," Walker said. "Their priorities are as a business, but where they can, they help out."

Ironically, there appears to be a way for scientists to help satellite operators by giving them the satellite-streaked images that aren't great for astronomical purposes. "We have been providing data to a dozen different companies or so, including SpaceX and Planet Labs," Walker said.

"I think it is a nice ancillary thing that we can offer," Rawls told Space.com, "because we're not redacting any of the pixels, ultimately."

Maybe the burden falls on scientists

This brings us to option two: Find a way to optimize Rubin data analysis so satellite streaks don't impede the incredible levels of data it'll be revealing. And, according to scientists speaking at the conference, it looks like those impediments could be pretty sizable.

Consider how satellites reflect sunlight while also circling our planet very quickly.

"They orbit fast — once every 90 minutes in low Earth orbit — and so you get a bright streak. Sometimes, it's a dashed line, sometimes it fades in and out, sometimes it's really bright, sometimes it's skinny, sometimes it's short," Rawls said. "It's actually necessary to be intrinsically fainter as you go to higher altitudes for the impact on Rubin's camera to be about the same. This is counterintuitive, because further-away things are, in fact, dimmer, but further out, things in orbit move slower, so therefore they linger."

To illustrate the potential negatives of this, Sarah Greenstreet, lead of the Rubin Observatory's Solar System Science Collaboration's Near-Earth Objects and Interstellar Objects working group, explained what could happen to solar system science conducted by Rubin amid a satellite frenzy.

For context, the observatory is expected to discover five million new solar system objects by the end of its 10-year-long survey. It's also going to be conducting what's called a "near-sun twilight, near-Earth object micro survey, which will look at objects very close to the sun.

"We're going to have potentially hundreds of these moving object detections, and then we take many, many images, so you have to be able to tell which dots connect to which dots moving in which direction between all of these hundreds of objects in each of these images," Greenstreet said during the conference, pointing to a visualization of this picture. "If we add artificial satellites into this [picture], you now have a whole bunch of other moving objects."

As Greenstreet explained, in order to detect a moving object with high certainty, Rubin will need to capture four pairs of images on four nights within 15 days. But what if even one of those eight images were tainted with a satellite streak?

"We fail to discover that moving object," she said.

She also pointed out a study from 2022 in which the authors simulated what kind of impact 40,000 satellites around Earth at less than seven magnitude — again, the recommended brightness level — would have on Rubin's mission, known as the Legacy Survey of Space and Time (LSST).

The conclusion was that between 10% and 30% of the main LSST fields would contain streaks. And if you put those satellites at lower altitudes, up to 50% of the exposures could have streaks present.

Study authors also found that, during twilight hours, every exposure taken will likely have at least one streak in it with these circumstances. About 15% of near-Earth objects expected to be found with Rubin could go missed because of satellite interference. "It's not huge, but I would be happy if it was much lower than that," she said.

"One caveat to this is, of course, that these numbers rely on satellites being in this range less than seven magnitude," she added. "If they're brighter than that, then all of these numbers are quite a bit worse."

To Rawls' point about working with satellite operators, Greenstreet also explained that knowing where the satellites are before pointing Rubin at a certain section of night sky — sacrificing about 10% of LSST time — could cut the number of main survey fields with streaks in half. There is also hope for the twilight survey specifically, because more images are taken. That means there's a higher chance the necessary four pairs are achieved with backup images.

"We're really worried about phenomena that would happen in a single exposure but may not appear in the second exposure," Bianco said.

"There was, in fact, already a claim for the discovery of a [gamma-ray burst] at z = 11," she said. ("Z" is a measurement of redshift, how much light has been stretched on its journey to our telescopes. A redshift of 11 indicates an incredibly old light source — one that was emitting just 400 million years or so after the Big Bang.) "It was revealed to be a streak from a satellite."

Rawls says her team is working on a database that labels where streaks and glints could fall due to satellite interference when looking through Rubin data.

The idea is to let scientists know when they're viewing objects in a zone known to have satellite streak occurrences, "so you have a better understanding of maybe where you would want to be cautious about being like, 'Oh, we found an amazing new supernova, never-before-seen.' And then you're like, 'Well, it was in that streak area … maybe that's actually just a glinting satellite," she said.

"There's this idea from Chris Stubbs of using different ground-based small telescopes at different places, right along the ridge, where all these telescopes are in Chile, and to look at the effects of these satellite trails moving across. But I don't think that it's reasonable or cost effective to have multiple LSSTs, for example, looking at different angles," Tyson said.

Though the conversation didn't quite reach any actionable solutions beyond what has been discussed as already in progress, like Rawls' work, there was one clear message potently felt across the room — one of urgency.

"This is now a working observatory," said Bob Blum, acting director for Rubin Observatory Operations, said.

"Every night — every minute — is precious."

A sweeping new satellite analysis shows that Antarctica has lost nearly 5,000 square miles (12,950 square kilometers) of grounded ice over the past three decades — an area roughly twice as big as Delaware — as warming ocean waters erode the continent's most vulnerable edges.

Led by scientists at the University of California, Irvine, the study traces how Antarctica's "grounding line" — the boundary where ice anchored to bedrock begins to float on the ocean — shifted between 1992 and 2025. Because that boundary marks where land-based ice begins contributing directly to sea level rise, its retreat signals ice-sheet instability and future ice mass loss.

"We've known it's critically important for 30 years, but this is the first time we've mapped it comprehensively across all of Antarctica over such a long time span," study lead author Eric Rignot of UC Irvine said in a statement.

Rignot and his colleagues analyzed data from a wide range of satellite missions operated by European, Canadian, Japanese, Italian, German and Argentine space agencies. Using radar instruments, the researchers tracked the vertical movements of floating ice shelves caused by ocean tides. Grounded ice remained fixed on bedrock, allowing them to pinpoint shifts in the grounding line over three decades with unprecedented precision.

The results show that about 77% of Antarctica's coastline experienced no detectable grounding-line migration since 1996, suggesting broad stability across much of the continent. But in vulnerable regions, particularly parts of West Antarctica, the Antarctic Peninsula and sections of East Antarctica, the study found "significant retreat."

The largest changes were detected along the Amundsen Sea coast of West Antarctica and in the Getz sector, where the grounding line in some places pulled back by as much as 26 miles (42 km) during the study period.

Retreat was most pronounced where deep underwater pathways funnel warm ocean water toward the base of glaciers, Rignot said. That warmer water melts ice from below, thinning floating shelves and weakening their ability to buttress the glaciers behind them.

"It's like the balloon that's not punctured everywhere, but where it is punctured, it's punctured deep," said Rignot.

The study also highlights a puzzling pattern along the northeast Antarctic Peninsula. In that area, several ice shelves collapsed before the study period and multiple glaciers have since retreated significantly, but researchers lack clear evidence that warm ocean water is driving the change.

"Something else is acting — it's still a question mark," Rignot said in the statement.

Beyond documenting what has already happened, the researchers say the new record provides a crucial real-world test for computer models used to project future sea level rise.

"Models have to demonstrate they can match this 30-year record to claim credibility for their projections," Rignot said in the statement. "That's the real value of this observational record: knowing that this grounding line migration has happened."

While much of Antarctica remains stable, Rignot cautioned that the current balance may not hold indefinitely.

"The flip side is that we should perhaps feel fortunate that all of Antarctica isn't reacting right now, because we would be in far more trouble," he said. "But that could be the next step."

This research is described in a paper published March 2 in the journal Proceedings of the National Academy of Sciences.

Since Sunday (Feb. 22) evening, an aggressive blizzard has been inundating the northeast U.S. with piles of snow and wind speeds rivaling those of a hurricane. For instance, according to CNN, Montauk Point in New York reported the fastest winds as of Monday (Feb. 23) at 84 miles (135 kilometers) per hour.

And as it all unfolds, satellites in space are capturing overhead views of the blizzard, which has officially been categorized as what's known as a "bomb cyclone." Both terms are technical, with the National Weather Service classifying a "blizzard" as a storm that leads to winds in excess of 35 miles per hour (56 km/h) and visibility levels less than a quarter mile for at least 3 hours.

A bomb cyclone, meanwhile is derived from the term "bombogenesis," which refers to when a storm's central pressure drops at least 24 millibars in 24 hours, intensifying the storm rapidly during this period and leading to active weather consequences like heavy snow, coastal flooding and high winds such as what the present storm is exhibiting.

In the image above, the GOES East satellite — part of the GOES-R program developed by NASA and the National Oceanic and Atmospheric Administration (NOAA) — reveals the spinning storm just off the coast of the northeast U.S. on Monday morning.

Impacted areas, as noticeable in this satellite footage, include Massachusetts, New York, New Jersey, Rhode Island and more. Several states have declared states of emergency and some areas have issued travel bans for nonessential trips until it's safe for transportation to resume.

GOES East also captured lightning strikes within the cyclone; this could be an indication of what's known as "thundersnow." According to the NOAA National Severe Storms Laboratory, this can happen in rare cases when there is "relatively strong instability and abundant moisture above the surface." Local news in Boston indeed reported thundersnow appearing above Scituate, Massachusetts early on Monday.

As of Monday afternoon, the blizzard is still in full swing with multiple feet of snow predicted to befall the hardest-hit locations. As of 7:00 a.m. ET on Monday, Central Park in New York City had about 15 inches (38 centimeters) of snow and Newark had 18.3 (46 cm) inches, per the NWS. Swansea, Massachusetts had snowfall reaching 26.5 (67 cm) inches on Monday, according to the weather service.

Wind speeds continue to top the charts, nearly 60 million residents in affected areas are under weather warnings and hundreds of thousands have lost power. Many experts are suggesting this storm could be a historic one; for instance, this is the first blizzard warning for New York City in nine years.

As more and more satellite megaconstellations continue to be launched into Earth orbit, some researchers are beginning to calculate the chances that people on the surface could be struck by the incoming remnants of these spacecraft reentering the atmosphere.

A new study by a team of Canadian researchers looks into eleven different megaconstellations and what would happen during their fiery reentry into Earth's atmosphere. What are the charred, declarative results? They find that there's a 40% collective risk of on-ground casualties if satellites do not burn up entirely.

The collective casualty risks modeled by Ewan Wright from the University of British Columbia and colleagues took into account well-funded constellations that, in total, represent some 73,369 satellites. As it turns out, researchers still can't quite predict what would happen if and when those fall back to Earth. "Scientific understanding of how satellites burn up in the atmosphere is not perfect and satellites may not burn up in the atmosphere entirely," Wright told Space.com. "If even a small piece of debris from each satellite survives reentry, the chance of someone getting hit could be considerable if thousands of satellites are launched in megaconstellations," he said.

"Minimum lethal amount"

In the study, the research team asked: "what happens if the minimum lethal amount of debris from each satellite does not burn up and reaches the ground intact?"

It turns out that materials used in satellites with lower melting points, such as aluminum, are more likely to demise entirely. But other spacecraft-making materials such as stainless steel, beryllium, titanium, tungsten, and silicon carbide are less likely to do so. These are commonly employed in fuel tanks and reaction wheels.

When satellites nose-dive into Earth's atmosphere, the Canadian team observes, aerodynamic forces cause them to break up. The intense heat of re-entry ablates their materials into fine particles. "However, many satellites, particularly large ones, do not burn up entirely," they explain. "Risky uncontrolled reentries of space objects should be the exception, rather than the norm."

Surviving debris

While spacecraft builders may strive for their satellites to demise entirely, Wright and fellow researchers add that there is considerable uncertainty in the degree to which total ablation can be achieved. And if a satellite does not burn up entirely, it creates a casualty risk.

"Many existing standards and guidelines only consider individual satellites, and don't consider the cumulative effect of launching and reentering thousands at once," said Wright.

Unless satellite operators purposely direct their satellites to reenter over a specific location on Earth in a "controlled re-entry" manner, that fall from space will be uncontrolled and surviving debris will be spread out over an area centered on a random location along the satellite's orbit.

Those satellite leftovers create a casualty risk to people on the ground and in aircraft in flight, as well as other problems, be they infrastructure damage and airspace closures.

Key question and recommendations

Wright and colleagues ask a key question in their analysis: Do we need so many satellites?

"It is possible to design constellations made up of fewer, higher capacity, higher quality satellites with longer operational lives. This, in turn, would reduce the risk to people on the ground and any damage to the atmosphere," they report.

As for what-next suggestions, the Canadian team offers a set of considerations.

Due to the large collective risks created by single megaconstellations, and the even larger cumulative risks from all constellations, they recommend:

• "states and their national regulators should require independent verification of claims of full 'demisability'
• evaluate collective casualty risks from entire constellations
• pursue a smooth transition to a fair, equitable, and globally applicable controlled reentry regime"

The study "Satellite megaconstellations and collective casualty risks" was published Feb. 6 in the journal Space Policy.

Space is getting crowded — nowadays, over 45,000 human-made objects orbit Earth. A portion of that figure is indeed represented by the thousands of satellites humans use for internet, GPS and other communications, but it also takes into account space junk from humanity’s previous space escapades.

Thus, figuring how to prevent collisions has become more important as space agencies continue to rocket new technology into low Earth orbit — and there's already a brisk launch schedule planned for 2026. As such, researchers at the Lawrence Livermore National Laboratory (LLNL) in California have developed a new method for modeling orbits in cislunar space, which refers to the space between and around Earth and the moon.

The researchers modeled what a million orbits would look like over six years using an open-access database, or code that's publicly available, and a ton of processing power from the lab's supercomputers.

"When you have a million orbits, you can get a really rich analysis using machine learning applications," LLNL scientist Denvir Higgins said in an announcement. "You can try to predict the lifetime of the orbit, try to predict stability or try to do anomaly detection to see if an orbit is moving in a strange way."

The researchers found that about half of the orbits they modeled remained stable for at least one year, and just under 10% remained stable for the full six years of the simulation.

"If you want to know where a satellite is in a week, there's no equation that can actually tell you where it's going to be," LLNL scientist Travis Yeager said in the release. "You have to step forward a little bit at a time."

The amount of computing power required to track a million obits over a six-year period in a simulated environment is significant. LLNL said they used 1.6 million CPU hours, which would take more than 182 years to process on a single computer. But using the lab’s Quartz and Ruby supercomputers, it only took three days to run the simulations.

This work could be helpful in the future for determining busy intersections for satellites, LLNL says. The lab also noted that, as countries continue to launch satellites without worldwide coordination, this could be a useful tool.

It looks like China is getting in on the race to launch data centers into space.

The state-run China Global Television Network (CGTN) reported on Thursday (Jan. 29) that the main Chinese space company, the state-owned China Aerospace Science and Technology Corporation (CASC), will work on space-based data centers as a part of a larger five-year plan to expand the nation's already significant presence in space.

The five-year plan also includes efforts to expand resource development, like asteroid mining. Furthermore, the plan also cites space debris monitoring and an expansion into space tourism.

The part of the plan that focuses on data centers will target an "integrated space system architecture combining cloud, edge and terminal technologies," according to CGTN. CACS says this will allow computing power, storage and transmission from space.

The news comes as U.S. companies are working to launch data centers into space, as terrestrial-based power is becoming more expensive and limited in some parts of the world. This is partially due to the rapid expansion of data centers used to host the massive information systems underlying artificial intelligence.

Elon Musk's SpaceX, for example, plans to launch space-based data centers. These will initially be modified versions of Starlink broadband satellites. But Musk’s typically ambitious long-term plans also include building AI-satellite factories on the moon, which will be launched from the lunar surface via railguns.

Houston-based company Axiom Space launched the first components for its orbiting data center last year, and Google is looking into launching a data center to support its own AI infrastructure. Tech companies are so hot on putting data centers in orbit because competition for the resources that support them — energy and land, for instance — are heating up on Earth. Solar power is plentiful in space, as is real estate, the thinking goes.

Orbiting data centers also came up at the World Economic Forum's annual meeting in Davos, Switzerland, last month. A panel that included European Space Agency Director General Josef Aschbacher discussed ways to ensure that the fast-moving technological developments that underpin society, such as internet infrastructure, are properly protected, as security for new technology often trails its development.

What actually happens to a spacecraft during its fiery last moments? That's the key question for the European Space Agency's (ESA) Destructive Reentry Assessment Container Object (Draco) mission.

ESA has greenlit the program that will create a highly complex reentry of a spacecraft specifically built to dive into Earth's atmosphere while loaded with a variety of sensors.

As the Draco spacecraft falls into thicker and thicker air while it enters the atmosphere, it will collect data on how materials react and introduce pollutants into the upper stratosphere. In other words, it's an atmospheric stab for science.

Last moments

ESA is strongly backing an ambitious Zero Debris approach, an undertaking that aims to prevent more space debris by attempting to lower the risk that spacecraft will produce debris from collisions.

As part of that, ESA scientists are studying what happens when satellites burn up. Reentry science is an essential element of what's dubbed "design for demise" efforts, said Holger Krag, ESA Head of Space Safety.

"We need to gain more insight into what happens when satellites burn up in the atmosphere as well as validate our re-entry models," Krag said in an ESA statement focused on the Draco initiative.

"That's why the unique data collected by Draco will help guide the development of new technologies to build more demisable satellites by 2030," said Krag.

Strain gauge

Draco's sensors will be measuring temperatures, gauging the strain on the various parts of the satellite itself, and register the surrounding pressure. Four additional cameras will be pointing at the spacecraft to watch the destruction and collect contextual information.

Planned for 2027, the Draco satellite is anticipated to tip the scales at between 330 to 440 pounds (150-200 kilograms). About the size of a washing machine, Draco would purposely pile-drive itself over an ocean uninhabited area just some 12 hours after being put into Earth orbit.

Fiery frenzy

Outfitted with 200 sensors and 4 cameras to record its fiery frenzy, the 1.3 foot diameter (40 centimeters) capsule would store data safely onboard. Once its parachute is deployed, Draco would connect to a geostationary satellite, outputting its data.

According to ESA planners, there will be about a 20-minute window to transmit telemetry before it splashes down into the ocean, concluding the Draco mission's assignment.

If all goes well, Draco would collect "real-world data" on what occurs as space hardware takes the heat, shatters and scatters during reentry. It's a process that researchers can only mimic today on Earth in wind tunnels or via computer models.

"Understanding how different materials behave as they burn up," ESA explains, "could help engineers design satellites that fully disintegrate, leaving nothing behind in orbit or in the atmosphere."

Ablation products

The case for Draco data is front-and-center explain space debris experts.

"Reentries create several issues for general space sustainability," said Aaron Boley, a professor at the University of British Columbia for physics and astronomy and co-director of the Outer Space Institute.

If uncontrolled, they impose casualty risks to people on the ground and in aircraft in flight, Boley told Space.com, and can further be disruptive to air traffic should there be sudden airspace closures in reaction to the reentries.

"They also deposit ablation products directly into the upper atmosphere," Boley said.

One approach to addressing casualty risks is to design spacecraft to demise entirely, but this exacerbates the atmosphere pollution problem, said Boley. "Moreover, reentry ablation models are insufficiently verified due in part to limits on lab testing."

Complex problems: safety and pollution

Experiments that can monitor the on-the-spot demise of a satellite and the types of emission products that are produced upon reentry are very valuable for addressing the interconnected and complex problems of safety and pollution, Boley added.

While not taking part in the Draco project, Boley said that characterizing the types of ablation products "is of high priority" as doing so enables investigators "to better understand how reentry emissions will affect upper atmosphere aerosols and associated chemistry, with implications for ozone, climate balance, upper atmosphere polar clouds, and atmospheric transmission," said Boley.

Piece of the puzzle

Leonard Schulz is a researcher at the Technische Universität Braunschweig's Institute of Geophysics and Extraterrestrial Physics in Braunschweig, Germany.

Also not engaged in ESA's Draco initiative, Schulz said that the results of the undertaking would be eagerly awaited.

"In-situ measurements are one important piece of the puzzle missing to better understand destructive spacecraft re-entry and its effects on the atmosphere," he told Space.com.

"I look forward to the results of this mission. Hopefully, it can serve as a pathfinder for in-situ observations of spacecraft fragmentation and especially their ablative behavior," said Schulz.

Relevant data

Similar in view is Luciano Anselmo, a researcher at the Space Flight Dynamics Laboratory within the National Research Council's Institute of Information Science and Technologies in Pisa, Italy.

Draco will be a single spacecraft reentry, with a specific trajectory, mass, and design, Anselmo said.

Not involved in the Draco program, Anselmo told Space.com that the experiment aims to be as representative as possible and, if successful, will allow for the collection of a lot of relevant data.

"This data could not only prove to be much more generally applicable than one might initially think," said Anselmo, "but could also reveal something unexpected, fostering new lines of investigation."

Weather forecasts, modern banking, international trade and GPS all depend on a fragile web of infrastructure extending from Earth's orbit to the ocean floor — a web that's largely unseen and, experts warn, increasingly at risk.

At a World Economic Forum discussion in Switzerland last week, space leaders and cybersecurity experts cautioned that the satellites orbiting Earth and the submarine cables crisscrossing the seabed — the hidden lifelines of modern society — are growing more vulnerable even as global reliance on them accelerates.

The panel, which included European Space Agency (ESA) Director General Josef Aschbacher, said that technology is advancing faster than the legal, regulatory and security frameworks meant to protect these shared domains. That gap, the experts said, raises concerns about long-term stability and the risk of geopolitical conflict.

"People don't realize how dependent we are," Aschbacher said during the session on Jan. 21. "We have to catch up," he added, when asked whether enough was being done to protect the space infrastructure. "We have to do more."

More than 15,000 active satellites currently orbit Earth, many flying in constellations that provide internet and communications services. SpaceX's Starlink network alone accounts for more than 9,500 of them. If all proposed constellations now under regulatory review move forward, the total could swell to around 500,000 satellites by the late 2030s.

Together with roughly 600 submarine cables spanning the ocean floor, these systems underpin multiple aspects of modern life, supporting everything from navigation and weather forecasting to financial transactions, emergency response and military operations.

"They have two things in common," said Jessica Rosenworcel, executive director of the MIT Media Lab and former chairwoman of the U.S. Federal Communications Commission. "We don't think about them very often ... and they're both extraordinarily vulnerable."

Satellites face threats from tens of thousands of pieces of trackable space debris, as well as millions of untrackable fragments, space weather and cyberattacks. Submarine cables, meanwhile, can be damaged accidentally by marine life or deliberately targeted in geopolitical flashpoints, such as attacks in the Red Sea that interrupted internet access in parts of Asia and the Middle East last year, said Rosenworcel.

"The vulnerabilities are all shared," she said, "but our regulatory frameworks around the world are pretty dated."

Cybersecurity threats are already testing some of those frameworks, according to Robert Lee, the CEO of Dragos, a Washington D.C.-based cybersecurity company. Lee pointed to a thwarted cyberattack on Poland's energy grid last December, which Polish authorities linked to Russian intelligence services. Had it succeeded, the attack could have triggered a blackout, leaving nearly half a million people without heat during the height of winter, according to news reports.

In the space sector, NASA faced an average of one cybersecurity incident per day during a month-long government shutdown in 2019. More recently, ESA launched a criminal investigation after a series of cyberattacks led to the leak of hundreds of gigabytes of potentially sensitive data. The material, which appeared on dark-web forums, reportedly included the agency's proprietary software, authorization credentials and internal project documentation.

Despite the critical role played by data centers and energy grids, Lee said such infrastructure remains "massively underinvested" in cybersecurity resilience — an area "that gets very little attention." In at least one case, he added, a state-backed actor penetrated systems with the explicit intent to cause physical harm.

"We see a lot more than you'll ever see in the media," Lee said during the session. As more systems become interconnected both in space and on Earth, he cautioned that ignoring the "very-real scenarios that are already taking place" could mean "we can very much find ourselves in a world where we're causing societal harm by the very innovation that we're trying to capture."

Still, Lee stressed that effective defense is achievable. "It's not that we are trying to come up with some net-new innovations to keep ahead of the adversaries," he said. "Sometimes it's very basic."

In space, too, rapid growth of satellite constellations can improve redundancy and resilience. But that growth also increases congestion in orbit and raises the risk of collisions and debris incidents.

"This is one of those challenges which reflects on the fact that, very often, tech develops much faster than international laws and regulations that are supposed to govern it," Rafal Modrzewski, the CEO and co-founder of the Finnish radar-imaging company ICEYE, said during the session. "It is a problem that we will have to address as a community."

ICEYE recently signed a €1.7 billion ($2 billion US) contract with the German government to build a 40-satellite radar constellation, one of the largest single Earth-observation deals to date, according to Modrzewski.

Such capabilities are already reshaping how space-based data is used on Earth. In Japan last year, ICEYE's near real-time satellite data was used to accelerate insurance payouts during flooding, allowing compensation to be issued within hours based on detected water depth — sometimes even before affected residents had filed a claim, Modrzewski said.

"You didn't even know that your car was flooded and you had the money in your bank account," he said. "That's the type of future we're talking about — if we can build this infrastructure correctly."

Adding to the complexity, satellites themselves are becoming increasingly autonomous. Recent research has shown that satellites can now use AI to control their orientation in space without human input, reducing the time, cost and operational burden of directing them remotely. But experts say that autonomy also deepens reliance on orbital systems that must operate safely in an increasingly crowded and contested environment.

AI is already being used on the defensive side as well. For example, it was recently used to help protect space assets by identifying vulnerabilities in communication links between Earth and NASA spacecraft, closing a flaw that for three years left the agency's network exposed to potential exploitation. In a worst-case scenario, such vulnerabilities could have allowed attackers to intercept sensitive data or even seize control of spacecraft, including those involved in flagship Mars missions.

Other protective technologies are emerging alongside these software-based defenses. Georgia-based Atomic-6, for example, has developed "space armor" designed to protect onboard communications without interfering with radio signals. The technology has undergone extensive hypervelocity testing on Earth and is expected to face its first in-orbit trials this year.

And more than 100 countries have signed the Zero Debris Charter led by ESA, aimed at strengthening international cooperation to address the growing problem of space junk.

Still, these efforts are only the beginning, Aschbacher said. "We are on Day 1. A lot more needs to be done."

Reflecting on his own journey building a satellite with ICEYE co-founder Pekka Laurila — a project that eventually led to the company's launch — Modrzewski encouraged young people entering the space industry to pursue bold ideas.

"Go and do it," he said. "Solve the problems that are out there, and let's make this world a better place."

The satellites in Amazon's new internet-beaming megaconstellation in low Earth orbit (LEO) are bright enough to disrupt astronomical research, a study has found.

The study — which was posted on the online repository Arxiv on Jan. 12 but has not yet been peer-reviewed — analyzed nearly 2,000 observations of Amazon Leo satellites. It concluded that the spacecraft exceed the brightness limit recommended by the International Astronomical Union (IAU) that aims to ensure harmless coexistence of satellite megaconstellation with astronomical research.

The internet-beaming satellites, orbiting at an altitude of 391 miles (630 kilometers), have an average apparent magnitude of 6.28, which is too dim to be visible to the naked eye, but still bright enough to bother astronomers. In about 25% of observations, the satellites appeared bright enough to be observable without telescopes.

"Bright satellites are particularly troublesome for large-scale astronomical surveys being conducted at ground-based observatories such as the Vera C. Rubin Observatory," study lead author Anthony Mallama, an astronomer at the IAU Center for Protection of the Dark And Quiet Sky, told Space.com in an email. "However, they can also interfere with orbiting observatories like the Hubble Space Telescope."

Mallama and his colleagues have previously studied the brightness of other satellite networks, especially SpaceX's Starlink, which, with around 9,500 satellites, is by far the largest constellation in orbit today. They also observed the giant BlueBird satellite arrays operated by AST SpaceMobile, whose antennas, which cover 690 square feet (64 square meters), make them the brightest artificial objects in the night sky. (And the next-gen BlueBirds are even bigger, with antennas covering nearly 2,400 square feet, or 223 square m).

Mallama noted that satellites in the Amazon Leo constellation (which used to be known as Project Kuiper) are significantly dimmer than the BlueBirds and slightly fainter than most Starlink satellites, which orbit at a lower altitude of around 300 miles (480 km). Mallama, however, added that the Starlink constellation benefits from being in Earth's shadow for most of its orbital time, which makes it less obtrusive.

Future Amazon Leo satellites are expected to orbit at lower altitudes of around 366 miles (590 km), which will further increase their brightness.

John Barentine, an astronomer at the Silverado Hills Observatory in Tucson, Arizona, and a dark sky expert who did not participate in the new study, said that the Amazon Leo satellites appear especially bright during twilight.

Amazon began launching its internet constellation in 2025. So far, only 180 satellites have been placed into orbit, but Amazon plans to grow the constellation to more than 3,200 spacecraft.

Mallama, however, lauded Amazon for its willingness to engage with astronomers and work on reducing the impact of its satellites on the night skies.

"Satellite operators such as Amazon and SpaceX are working with the astronomical community to reduce the brightness of their satellites," Mallama said. "One method is by making the underside of the spacecraft mirror-like so that sunlight is reflected into space rather than scattering to the ground. Another is to orient the satellites' components so that observers on the ground do not see the sunlit sides."

Barentine added that, since the launch of Amazon's first test satellites in 2023, the company's engineers have managed to reduce the amount of light the orbiting satellites reflect to Earth and therefore their visibility in the night sky.

"Amazon Leo is an instance in which the operator established a dialogue with astronomers early in the design phase of their constellation," said Barentine. "It is encouraging to see that this effort has yielded some success."

Astronomers began sounding alarm bells about the impact of satellite megaconstellations on the observations of the universe shortly after the launch of the first batch of SpaceX's Starlink satellites in 2019. Back then, they revealed streaked images, affected by the trails left behind by satellites passing in the view of telescopes. But since then, SpaceX too has worked on reducing the brightness of its satellites.

Still, an earlier report — published by Mallama and his colleagues in the journal Monthly Notices of the Royal Astronomical Society in November 2025 — found that, with the exception of OneWeb satellites, which orbit at higher altitudes of 745 miles (1,200 km), all currently operational internet-beaming constellations, including the Chinese projects Qianfan and Guowang, were exceeding the IAU-recommended brightness limits.

At least three large pieces of space debris — old satellites and spent rocket stages — fall back to Earth every day on average, but researchers have only a very limited understanding of where these potentially dangerous fragments land and what happens to them in the atmosphere. A new method, based on sonic boom tracking by earthquake sensors, could provide real-time information about the hurtling debris fragments' whereabouts.

In November 2022, Spain and France shut parts of their airspace for about 40 minutes as a giant piece of a Chinese rocket was predicted to potentially come crashing down in southern Europe. The shutdown diverted or delayed hundreds of flights and cost millions of dollars. The rocket body eventually reentered on the other side of the globe, reentering over the Pacific Ocean.

The incident demonstrated how little current space traffic monitors know about the behavior of stuff returning from orbit. The new method, developed by researchers from Johns Hopkins University and Imperial College London, could help us get a better handle on the problem in the future.

The space community predicts paths of reentering space debris based on measurements from a global network of radars and optical telescopes. This approach is sound, but it has limitations.

"The space situational awareness radars and optical tracking are great when the object's in orbit," study lead author Benjamin Fernando, a postdoctoral fellow at Johns Hopkins University, told Space.com. "But once you're below a couple of hundred kilometers in altitude, the interactions with the atmosphere become quite chaotic, and it's not always apparent where the piece of debris will re-enter."

Ground-based radars are sparsely distributed around the globe and struggle to monitor the disintegration of the returning space object, Fernando added. Moreover, the measurements are not immediately available to everyone who might need them.

On the contrary, large parts of the globe are quite densely dotted with seismic sensors designed to detect earthquakes, and those measurements are mostly openly available online. In addition to tremors emanating from within the planet, these sensors detect explosions, traffic vibrations and even the vocalizations made by whales in the oceans.

In the new study, Fernando and his colleagues used data from such seismic sensors to reconstruct the path of an orbital module that detached from China's Shenzhou 17 crew capsule and fell to Earth in April 2024.

The 1.5-ton piece of junk was expected to come crashing down in the South Pacific or the North Atlantic, Fernando said. But both of these predictions "were completely wrong," he added.

The researchers analyzed data from 127 earthquake sensors spread across California to discern the propagation of the sonic boom produced by the Shenzhou 17 module as it hurtled through Earth's atmosphere at up to 30 times the speed of sound. They saw it travel about 25 miles (40 kilometers) north of the trajectory predicted by U.S. Space Command, with some fragments possibly crashing down somewhere between Bakersfield, California, and Las Vegas, Nevada.

"There's 50 million people living under that flight path," Fernando said. "It doesn't necessarily appear that any debris reached the surface from that event, but it could have done."

Fernando says that, while the data cannot forecast where a piece of space debris will crash-land, it can help accurately track down the impact locations, allowing ground teams to retrieve any possibly toxic fragments that could pose a hazard to the environment.

"A supersonic object will always outrun its own sonic boom," Fernando said. "You're always going to see it before you hear it. If it's going to hit the ground, there is nothing we can do about that. But we can try to reduce the time it takes to find fragments from days or weeks down to minutes or hours."

He mentioned a 1978 incident when a re-entering Russian satellite broke apart over Canada, scattering radioactive debris from its onboard nuclear reactor. Most of that toxic junk was never found, Fernando added.

The new tracking method may also help answer the big unknown of how much space debris actually reaches the surface of Earth. For example, SpaceX claims that the satellites in its Starlink internet-beaming megaconstellation completely evaporate during their fiery reentry, but many experts question this assessment, claiming that some components, such as fuel tanks and batteries, are made of extremely sturdy materials and are therefore likely to survive. Having a better understanding of how completely satellites burn up in the atmosphere will help experts better assess the risk these objects pose to people and property on Earth, as well as to cruising aircraft.

"In this study, we show that the seismic network we have in the U.S. is able to track the sonic booms from the debris, which allows us to identify the trajectory, speed and descent angle and also characterize some of the breakup process," said Fernando. "This kind of detailed probing of the reentry process is really interesting, because it allows us to understand a little bit more about how the object is interacting with the atmosphere and whether or not any fragments will reach the ground."

The seismic sensors used in this study turn ground vibrations into electrical signals that can detect sonic booms at distances of several hundred miles, said Fernando. But a different kind of sensor network, based on acoustic measurements, exists, which could further increase the method's reach. In future studies, the team wants to analyze outputs of these other sensors and potentially track space debris across even larger areas.

"The acoustic sensors sense things from thousands of miles away," Fernando said. "They are able to pick up the launch of the Starship rockets [from Texas] from Alaska. They potentially can listen out over the open ocean for the noise of reentries, which would be great because there's no seismic data and very little radar data over the ocean. So SpaceX may claim that Starlink satellites demise over the Pacific, but there is no way to actually check that out."

The study was published on Thursday (Jan. 22) in the journal Science.

SpaceX lit up the night sky over Vandenberg Space Force Base today (Jan. 22) with the launch of 25 more satellites for its Starlink broadband internet service.

A Falcon 9 rocket lifted off from Vandenberg's Space Launch Complex 4 East today at 12:47 a.m. EST (0547 GMT; 9:47 p.m. on Jan. 21 local California time. The Falcon's upper stage reached a preliminary orbit about nine minutes later and released its Starlink payload (known as Group 17-30) as scheduled, roughly an hour after launch.

"Deployment of 25 Starlink satellites confirmed," SpaceX confirmed on social media.

The Falcon 9's first stage, known as Booster 1093, completed its 13th flight, landing on the Pacific Ocean-based drone ship "Of Course I Still Love You."

The new batch of satellites add to the 9,500 active units that comprise the Starlink megaconstellation. The service provides internet access to underserved areas around the world, as well as to airlines wanting to offer WIFI and cell phone carries seeking direct cell-to-satellite service for emergencies.

Thursday's launch was SpaceX's ninth of the year and 592nd since 2010.

Yet another satellite megaconstellation is in the works, this one from Jeff Bezos' Blue Origin.

The Washington-based aerospace company announced today (Jan. 21) that it plans to build a network called TeraWave, which will consist of 5,280 satellites in low Earth orbit (LEO) and 128 a bit higher up, in medium Earth orbit (MEO).

"This network will service tens of thousands of enterprise, data center and government users who require reliable connectivity for critical operations," Blue Origin said in an X post today.

As that post notes, TeraWave is targeting a customer base of big businesses and government agencies — organizations that want or need very high-throughput communications services.

TeraWave's LEO satellites will deliver speeds of up to 144 gigabits per second using radio frequency links, according to a Blue Origin statement. And the MEO spacecraft will be even more capable, using lasers to provide speeds of up to 6 terabits per second.

"TeraWave addresses the unmet needs of customers who are seeking higher throughput, symmetrical upload/download speeds, more redundancy and rapid scalability," Blue Origin's statement reads. "It enables customers to choose throughput and physical presence in response to changes in their needs."

Blue Origin plans to start building out the constellation in the fourth quarter of 2027.

A number of other satellite-internet megaconstellations are under construction. SpaceX's Starlink, for example, already services customers around the globe using a network of more than 9,500 satellites (and that number is growing all the time).

Two Chinese megaconstellations — Guowang ("National Network") and Qianfan ("Thousand Sails") — are under construction in LEO as well. Both will eventually consist of more than 13,000 spacecraft, if all goes according to plan.

And Amazon, which Bezos founded back in 1994, is assembling a 3,200-satellite network in LEO called, appropriately enough, Amazon Leo (though it was initially named Project Kuiper). Like Starlink, Amazon Leo is tailored more to everyday residential users.

Space debris is a growing problem, and not just in Earth orbit.

Once a week, on average, a spacecraft (or part of one) falls back into Earth's atmosphere; most of these objects are empty rocket stages, but some are dead satellites whose low orbits finally decayed enough for them to slip into the atmosphere. They're basically like human-made meteors, but most of them don't survive long. This is because of the heat and shredding force that come with high-speed collisions with the air. However, some bits of debris from the objects can exist long enough to plummet through the sky, ranging from dust-mote-sized particles to whole propellant tanks. And this can be a big problem.

There's a risk one of those stray pieces can hit a passing aircraft — that risk is small, but it's growing enough that experts are now trying to figure out how to reduce it.

We've been lucky so far

Even in space, what goes up sometimes comes back down: spent rocket stages, defunct satellites and other bits of space debris are falling back into Earth's atmosphere with increasing regularity. And as satellite constellations and general spacecraft operations continue to become more common, the risk of deorbiting space debris will only go up.

There's a 26% chance that sometime in the coming year, space debris will fall through some of the world's busiest airspace during an uncontrolled re-entry, according to a paper published early in 2025 by researchers at the University of British Columbia. The odds of that debris actually striking an aircraft (or vice versa) are small but measurable: By 2030, the chances of any given commercial flight hitting a piece of falling space debris could be around 1 in 1,000, according to a 2020 study.

Those odds don't sound terribly daunting if you're the gambling type, but given the number of planes crisscrossing the friendly skies at any given moment, that's a lot of rolls of the dice. And it's a high-stakes gamble; risk includes not just the likelihood of an event, but the potential outcome (hundreds of people dead, in this case of that 2020 study). That's partly because commercial aircraft carry so many passengers, but it's also because it takes a much smaller bit of debris to cause a catastrophe in the air than on the ground, especially where jet engines are concerned.

"Aircraft can be affected by much smaller pieces of debris. For example, airplanes flying through the ash of a volcano is risky because of the small particles," European Space Agency space debris system engineer Benjamin Virgili Bastida told Space.com. "Kind of a similar thing could happen with re-entering debris." Virgili Bastida and his colleagues recently published a paper in the Journal of Space Safety Engineering outlining the challenges of deciding when and where to close airspace for falling space debris.

Lessons learned from Long March

One of the best known incidents of space debris affecting air traffic happened in November 2022, when the core stage of a Chinese Long March 5B rocket re-entered Earth's atmosphere. It was the fourth time a Long March 5B had made an uncontrolled re-entry, and this time its ground track passed over Spain, prompting a flurry of airspace closures.

The Long March rocket was an unusual problem even by space debris standards; the roughly 20-ton core stage was much, much more massive than most spacecraft and rocket parts that drop back into the atmosphere (and China is no longer using that version of the rocket now that the final modules of its Tiangong space station are in orbit). China's space agency also wasn't very forthcoming about the rocket's track or the fact that it was going to re-enter the atmosphere at all. But despite being an anomaly, the Long March incident is also a good illustration of both the potential danger and the need for more specific warnings, rather than broad ones.

Despite a few other close calls and airspace closures in recent years — like a SpaceX spacecraft that re-entered over European airspace in the summer of 2025, prompting airspace closures — we've been lucky so far. But maintaining that streak, without causing air-traffic gridlock by closing too much airspace for too little reason, is going to require a lot of work on multiple fronts.

"What we are trying to investigate in the studies we are running is to see what is really the threshold for risk for an aircraft," said Virgili Bastida. "At what risk should we react?"

Other pieces of the puzzle include limiting the amount of debris that even makes it to the altitudes where most planes fly (around 30,000 to 40,000 feet or 9,144 to 12,192 meters), more accurately predicting where and when spacecraft will re-enter, and coordinating between space agencies and air traffic controllers to make the decision-making progress less clunky. And none of that is as easy as it sounds.

Really wide margins of error

It's still surprisingly hard to predict exactly where and when an uncontrolled satellite is going to fall into the atmosphere. Even during a doomed spacecraft's final orbit or two, the margin of error allows for several hours, which translates into thousands of miles of distance due to the speed most re-entering satellites move. The huge uncertainty presents air traffic controllers with a difficult choice: take no action and risk lives (even if the chances are small), or close a huge swath of airspace, which will inevitably cost millions of dollars and create air traffic delays that take hours to unsnarl.

For example, the 2022 Long March 5B airspace closure in Spain delayed, canceled, or rerouted more than 300 flights; Enaire (the Spanish equivalent of the FAA), shut down a strip of airspace about 62 miles (100 kilometers) on either side of the rocket stage's path for about 40 minutes. But the debris only spent about five minutes of that time in the affected airspace, according to Virgili Bastida.

"There's a desire to be more specific and make those windows and closures as narrow and constrained as safety allows," space and aviation analyst Ian Christensen, senior director for private sector programs at the Secure World Foundation, told Space.com. Christensen added that both the FAA and the International Civil Aviation Organization are already working with the space launch industry — companies like SpaceX, ULA and Blue Origin, among others — to develop narrower, more specific airspace closures for rocket launches. Those efforts are likely to apply to dealing with the other end of spaceflight, returning debris, as well.

To get there, space agencies and air traffic controllers need two key types of information. First, when and where will the spacecraft hit the atmosphere? How much of it will survive intact down to 40,000 feet? Exactly what part of the sky will that debris be falling through (and when)?

Second, how big a threat is that debris to a passing aircraft? That answer depends on the size, speed and features of the aircraft, and researchers are in the process of working out models that can offer more specific answers. It will then be up to space agencies and air traffic controllers, working together, to decide when the risk is high enough to close a patch of sky — and for how long.

"If we react at every risk, half of the world will be impacted every now and then, so it's not feasible," said Virgili Bastida. "Do we react for everything which has a chance to reach the ground? Or do we react only for the very large objects, as we did for the Long March?"

Agencies in charge of aviation and air traffic control in individual countries (like the FAA in the U.S. and the Civil Aviation Administration of China in China) will eventually have to define how much risk requires them to close airspace for falling space debris. That could include factors like the likely size of the pieces and the chances of an impact, so a standard might look something like, "If there's a 1 in 3,720 chance of particulate matter getting sucked into a jet engine, we should close the airspace." (Those numbers are just for illustration.)

Better predictions need more data

The margin of error is so large, in part, because we don't really know much about the detailed physics of the upper edge of the atmosphere, between 62 and 124 miles (100 and 200 kilometers) up. The term "upper edge" is misleading, in fact, because the transition from vacuum to air is more gradual, and the altitude where it happens depends on temperature and other factors — including how active the sun is at that moment. All of those factors affect how quickly the atmosphere's drag can slow down a spacecraft and pull it in.

Satellites don't spend much time passing through this rarefied region, and most of them are already dead and in the process of being disintegrated by the friction of the thin air against their hulls.

"There is very little information on this region of the atmosphere, so the models are just kind of extrapolated down or up," said Virgili Bastida.

Building better models requires more data, and one way of getting that data is ESA's upcoming DRACO (Destructive Re-entry Assessment Container Objective) mission. When it launches in late 2027, DRACO will measure — in 200 sensors' worth of detail — exactly how a small satellite disintegrates during its plunge into Earth's upper atmosphere. Its goal is to measure not just the spacecraft's trajectory on the way down, but exactly when different components burn or break apart.

To do that, DRACO's lead system engineer Alex Rosenbaum and his team are fitting the DRACO capsule with components in a range of different materials, each outfitted with sensors to measure its temperature and the time and altitude of its fiery demise. There will even be a mock-up of a propulsion bay and a composite fuel tank, even though DRACO won't actually have working propulsion. The capsule itself won't survive, which is the point. A black box, similar to the flight data recorders used on commercial aircraft, will escape the high-altitude breakup via parachute.

"It is a very peculiar mission because it will be very short," Rosenbaum told Space.com. "We are working for several years on a mission that will be operative for a couple of hours."

Meanwhile, there's the Inter-Agency Space Debris Coordination Committee — a group of 13 space agencies whose members include JAXA, ESA, Roscosmos, CNSA and ISRO. IADC runs an annual exercise called a Re-Entry Campaign, in which members choose "an interesting test case" from among the defunct satellites due to drop back into Earth's atmosphere in the coming months. Member agencies pool their information on the object and their predictions about the time and path of its re-entry. Afterward, they compare what actually happened to their predictions in order to help test and refine those models. It's steady work with cumulative results — not too dramatic but very important.

The Re-Entry Campaigns and DRACO will help improve predictions and shed light on how to reduce the amount of space debris by designing satellites and rocket stages that disintegrate as completely as possible at high altitudes. But once space agencies and air traffic controllers have that data, someone is going to have to decide what to do with it.

What exactly does that look like?

Agencies have to talk to each other

First, air traffic controllers and national aviation authorities will need good information from, and regular communication with, the agencies that monitor space traffic and space junk. In the U.S., the FAA and the Department of Transportation, both of which regulate space launches as well as aviation. And at the United Nations, the U.N. Office for Outer Space Affairs is working with the Secretariat of the Civil Aviation Authority to build the kinds of connections that help experts exchange data and work together on studies.

And second, since the paths of re-entering spacecraft often cross national borders, aviation agencies and air traffic controllers in multiple countries will need to be able to communicate and plan. The Long March 5B incident in 2022 demonstrated what happens without that coordination: the Spanish airspace closures "concentrated and forced aircraft into other areas, which were still, anyway, under the remaining track," according to Virgili Bastida and his colleagues in their paper.

Building the kind of coordination that could make the next incident go more smoothly is crucial — and it needs to happen before the next incident, according to Virgili Bastida and his colleagues. That coordination is likely to take the form of standards: criteria and guidelines that define what's appropriate to do in a particular situation. In aviation, standards come from national agencies like the FAA and the European Union Safety Agency, or from international organizations like the International Civil Aviation Organization (a U.N. agency).

"The aviation world is very driven by standards, and we're seeing a lot of activity in the space world around standards as well," said Christensen. "Those give us ways to develop technical mitigation approaches, technical solutions, and then implement them at the national level with some coordination internationally.

"The sky is not going to fall on your head"

We may be approaching a future where closures or delays for re-entering space debris are as common as weather-related delays now. But if Virgili Bastida gets the world he's hoping for, that future is one in which we won't even notice, because re-entries will be predicted in advance and flight plans can just route around the affected areas.

"I'm optimistic that at the technical level and at the operational level, we'll be able to work on this issue and make significant success," said Christensen.

In the meantime, Virgili Bastida suggests that while policymakers and engineers need to be thinking about space debris and air traffic, the average traveler shouldn't lose sleep over the risks.

"The probability of being hit by space debris is very low, much lower than any other risk that we have in normal life. So even if there are many re-entries and it's kind of worrisome, it should not be your main worry," said Virgili Bastida. "The sky is not going to fall on your head. But we are working on ways to do it even better."

This article was originally published at The Conversation. The publication contributed the article to Space.com's Expert Voices: Op-Ed & Insights.

There are about 15,000 satellites orbiting the Earth. Most of them, like the International Space Station and the Hubble Telescope, reside in low Earth orbit, or LEO, which tops out at about 1,200 miles (2,000 kilometers) above the Earth’s surface.

But as more and more satellites are launched into LEO – SpaceX's Starlink internet constellation alone will eventually send many thousands more there – the region's getting a bit crowded.

Which is why it's fortunate there's another orbit, even closer to Earth, that promises to help alleviate the crowding. It's called VLEO, or very low Earth orbit, and is only 60 to 250 miles (100 to 400 kilometers) above the Earth's surface.

As an engineer and professor who is developing technologies to extend the human presence beyond Earth, I can tell you that satellites in very low Earth orbit, or VLEO, offer advantages over higher altitude satellites. Among other benefits, VLEO satellites can provide higher-resolution images, faster communications and better atmospheric science. Full disclosure: I'm also a co-founder and co-owner of Victoria Defense, which seeks to commercialize VLEO and other space directed-energy technologies.

Advantages of VLEO

The images from very low Earth orbit satellites are sharper because they simply see Earth more clearly than satellites that are higher up, sort of like how getting closer to a painting helps you see it better. This translates to higher resolution pictures for agriculture, climate science, disaster response and military surveillance purposes.

End-to-end communication is faster, which is ideal for real-time communications, like phone and internet service. Although the signals still travel the same speed, they don't have as far to go, so latency decreases and conversations happen more smoothly.

Much weather forecasting relies on images of clouds above the Earth, so taking those pictures closer means higher resolution and more data to forecast with.

Because of these benefits, government agencies and industry are working to develop very low Earth orbit satellites.

The holdup: Atmospheric drag

You may be wondering why this region of space, so far, has been avoided for sustained satellite operations. It's for one major reason: atmospheric drag.

Space is often thought of as a vacuum. So where exactly does space actually start? Although about 62 miles up (100 kilometers) – known as the the von Kármán line – is widely considered the starting point, there's no hard transition where space suddenly begins. Instead, as you move away from Earth, the atmosphere thins out.

In and below very low Earth orbit, the Earth's atmosphere is still thick enough to slow down satellites, causing those at the lowest altitudes to deorbit in weeks or even days, essentially burning up as they fall back to Earth. To counteract this atmospheric drag and to stay in orbit, the satellite must constantly propel itself forward – like how riding a bike into the wind requires continuous pedaling.

For in-space propulsion, satellites use various types of thrusters, which provide the push needed to keep from slowing down. But in VLEO, thrusters need to be on all, or nearly all, of the time. As such, conventional thrusters would quickly run out of fuel.

Fortunately, the Earth's atmosphere in VLEO is still thick enough that atmosphere itself can be used as a fuel.

Innovative thruster technologies

That's where my research comes in. At Penn State, in collaboration with Georgia Tech and funded by the U.S. Department of Defense, our team is developing a new propulsion system designed to work at 43 to 55 miles up (70 to 90 kilometers). Technically, these altitudes are even below very low Earth orbit – making the challenge to overcome drag even more difficult.

Our approach collects the atmosphere using a scoop, like opening your mouth wide as you pedal a bike, then uses high-power microwaves to heat the collected atmosphere. The heated gas is then expelled through a nozzle, which pushes the satellite forward. Our team calls this concept the air-breathing microwave plasma thruster. We've been able to demonstrate a prototype thruster in the lab inside a vacuum chamber that simulates the atmospheric pressure found at 50 miles (80 km) high.

This approach is relatively simple, but it holds potential, especially at lower altitudes where the atmosphere is thicker. Higher up, where the atmosphere is thinner, spacecraft could use different types of VLEO thrusters that others are developing to cover large altitude ranges.

Our team isn't the only one working on thruster technology. Just one example: The U.S. Department of Defense has partnered with defense contractor Red Wire to develop Otter, a VLEO satellite with its version of atmosphere-breathing thruster technology.

Another option to keep a satellite in VLEO, which leverages a technology I've worked on throughout my career, is to tie a lower-orbiting satellite to a higher-orbiting satellite with a long tether. Although NASA has never flown such a system, the proposed follow-on mission to the tether satellite system missions flown in the 1990s was to drop a satellite into much lower orbit from the space shuttle, connected with a very long tether. We are currently revisiting that system to see whether it could work for VLEO in a modified form.

Other complications

Overcoming drag, though the most difficult, is not the only challenge. Very low Earth orbit satellites are exposed to very high levels of atomic oxygen, which is a highly reactive form of oxygen that quickly corrodes most substances, even plastics.

The satellite's materials also must withstand extremely high temperatures, above 2,732 degrees Fahrenheit (1,500 degrees Celsius), because friction heats it up as it moves through the atmosphere, a phenomenon that occurs when all spacecraft reenter the atmosphere from orbit.

The potential of these satellites is driving research and investment, and proposed missions have become reality. Juniper research estimates that $220 billion will be invested in just the next three years. Soon, your internet, weather forecasts and security could be even better, fed by VLEO satellites.

We'll see a mass migration of SpaceX Starlink satellites this year.

All Starlink broadband spacecraft currently orbiting 342 miles (550 kilometers) or so above Earth — about 4,400 satellites — will descend to an altitude of roughly 298 miles (480 km) over the course of 2026.

There are two main reasons for the move, according to Michael Nicolls, vice president of Starlink engineering at SpaceX, who announced the plan via X on Thursday (Jan. 1).

"As solar mininum approaches, atmospheric density decreases, which means the ballistic decay time at any given altitude increases — lowering will mean a >80% reduction in ballistic decay time in solar minimum, or 4+ years reduced to a few months," Nicolls wrote in his X post. "Correspondingly, the number of debris objects and planned satellite constellations is significantly lower below 500 km, reducing the aggregate likelihood of collision."

Solar activity waxes and wanes on an 11-year cycle. We likely just passed through the maximum phase of the current one, known as Solar Cycle 25. (Scientists have been tracking these cycles diligently since 1755, when the numbering system began.) The next solar minimum is expected in 2030 or thereabouts.

As Nicolls noted, the atmospheric changes wrought by solar activity are of great interest and importance to satellite operators. An active sun causes a thicker atmosphere, which increases frictional drag on spacecraft and brings them down faster. Low solar activity has the opposite effect.

The downward migration in 2026 involves roughly half of SpaceX's Starlink megaconstellation, which currently consists of nearly 9,400 operational spacecraft (though that number is always growing). The fleet is highly reliable; there are just two dead Starlinks currently in orbit, according to Nicolls.

"Nevertheless, if a satellite does fail on orbit, we want it to deorbit as quickly as possible," he wrote. "These actions will further improve the safety of the constellation, particularly with difficult-to-control risks such as uncoordinated maneuvers and launches by other satellite operators."

Low earth orbit (LEO) is getting increasingly crowded these days. Starlink is the main driving factor; about two-thirds of all operational satellites belong to the megaconstellation. But other giant networks are being assembled as well. For example, China has begun building out two LEO internet constellations, each of which will each feature more than 10,000 spacecraft if all goes to plan.

Earth's orbital environment is becoming increasingly crowded. Thousands of satellites—many of them inactive, damaged, or out of fuel—now circle the planet alongside fragments of debris from past collisions.

As more and more satellites enter orbit, one of the biggest questions becomes: how can these satellites approach and maneuver around each other safely? To answer that question, Luxembourg-based companies LMO and ClearSpace carried out a carefully designed simulation using the European Space Agency's Guidance, Navigation and Control Rendezvous, Approach and Landing Simulator (GRALS).

What is it?

GRALS is part of ESA's Guidance, Navigation and Control Test Facilities and is built to recreate close-proximity operations in space with remarkable realism. The satellite model shown in this image was developed by ClearSpace to replicate the geometry, materials, and visual complexity of real satellites.

Its crinkled gold thermal insulation, metallic structures, and the cup-shaped reflective thruster are not just aesthetic details but critical features that influence how light behaves in space and how cameras perceive an object during a rendezvous.

To ensure reliability, engineers combine computer-generated imagery used to train AI systems with physical testing on increasingly realistic models. Smaller models simulate long-range approaches, while larger, high-fidelity replicas like the one shown are used to test the most delicate, close-range phases of a rendezvous.

Where is it?

This photo was taken at the ESA's technical center, ESTEC, in the Netherlands.

Why is it amazing?

The thousands of satellites orbiting Earth pose growing risks to operational spacecraft and to the long-term sustainability of space activities. Before a spacecraft can refuel, repair, or safely deorbit another satellite, it must be able to see, identify, and approach its target with exceptional accuracy. Vision-Based Navigation systems are key to making this possible. Much like self-driving cars rely on cameras and AI to interpret their surroundings, VBN-equipped spacecraft must interpret light, shadow, reflections, and rapidly changing viewpoints in the harsh environment of space.

Facilities like GRALS play a critical role in bridging the gap between theory and reality. By testing real hardware against realistic satellite models under space-like lighting conditions, engineers can expose weaknesses, validate AI training, and build confidence that autonomous systems will behave safely once deployed in orbit.

Want to learn more?

You can learn more about satellite crowding and space junk.

Quite a bit has happened in the space sector this year, out in the cosmos as well as on Earth — and actually, in Earth orbit, too.

For instance, U.S. President Donald Trump took office in only January, but his administration is responsible for a wealth of changes that have flipped life upside down for scientists in the States. China, Russia and India are meanwhile steadily strengthening their space programs, and other countries are starting to bloom toward the cosmos as well. Earth orbit, to say the least, is getting pretty crowded.

At the same time, an interstellar comet paid our solar system a surprising visit, black holes and neutron stars continue to baffle us with their mind-bending characteristics, the northern lights are suddenly appearing in skies across the world, a Mars rover managed to find rocky treasure on the Red Planet and science fiction has been captivating enough to float us into our imaginations on days when real things like spaceflight crashes and political encroachment on climate science get overwhelming.

But through it all, our reporters have been following the show.

So, to create a must-read story list for you, we asked our staff to select their favorite pieces of 2025. Alas, while you're drinking leftover hot chocolate or sitting in your room trying to escape questions from your extended family, here are some great reads, twisty reads, essential reads and long, joyful reads to relax into.

1. On NASA sinking its flagship science center and possibly breaking the law

Josh has been putting out amazing stories all year, but his investigative article revealing the sweeping and chaotic changes inflicted by NASA leadership on the Goddard Space Flight Center was of a different class. It was a considered, well-researched and thoughtfully written piece that explored the human cost of the administration's actions, while alerting the public to the long-term damage that the secretive moves could wreak on the agency's scientific capabilities.

It prompted discussion and action from both Space.com's readership and also the ranking member of the U.S. congressional committee on science, space and technology, Zoe Lofgren, who cited the story in a letter to NASA acting administrator Sean Duffy while demanding that NASA cease its actions and give "a full accounting of the damage inflicted on Goddard thus far."

TLDR: Josh is the journalist I want to be when I finally grow up.

NASA is sinking its flagship science center during the government shutdown — and may be breaking the law in the process, critics say

2. The perplexing saga of an astronaut imposter

After more than 20 years of space reporting, I thought I'd heard most of the crazy stories from the space age, but must admit that Jeff Maysh's tale of huckster astronaut wannabe Robert Hunt, who for years play-acted being an astronaut, took me by surprise. Through some meticulous reporting, and interviews with Hunt himself, Jeff recounts an astounding story of one man's determination to play the role of a space traveler without actually being one. It's an amazing story, more so for how long Hunt seemed to get away with it.

How a fake astronaut fooled the world, broke women's hearts, and landed in jail

3. Edwin Hubble's helpers and an aurora cruise

As an astronomy editor, I read and write about Edwin Hubble a lot, and in many different contexts. His presence permeates so much of physics as a whole, from the Hubble Space Telescope and Hubble's Law to the Hubble Constant and resulting Hubble Tension. But what science writer Keith Cooper did with his look back on how Hubble proved our Milky Way galaxy isn't alone in the universe is focus on the side characters responsible for Hubble's great success — characters very rarely spoken about. This engrossing read is where my rabbit-hole of knowledge about Milton Humason began, a janitor and mule skinner who helped with the construction of Mount Wilson Observatory, then went on to aid Hubble in several major discoveries.

I'm not sure if this is allowed, but I also have a second favorite that needs to be on this list. Maybe I was biased because I read this story after having a slightly rough day and sipping tea in my bed, but our editor Daisy Dobrijevic's long, narrative piece about being on a multi-day aurora cruise along Norway's frigid coast was really a treat. The vivid imagery and honest retelling of what emotions are involved when viewing neon ribbons in the sky make you feel like you were there. There's one bit about a window that has stayed in my mind. You'll know when you read it.

100 years ago, Edwin Hubble proved our Milky Way galaxy isn't alone

Is an aurora cruise worth it? I joined Hurtigruten's Signature Voyage to find out

4. Trump's desire to slash NASA's budget rattles scientists

I love how we leaned into writing about the current U.S. administration's questionable decisions this year, and this was one of my favorites. In times of controversy, in-depth reporting matters more than ever.

'What a waste:' US scientists decry Trump's 47% cuts to NASA science budget

5. A NASA satellite corpse in disguise

This story from Rob Lea dives into a space mystery, which are always my favorite, and explores how a dead NASA satellite ended up fooling astronomers into thinking they had discovered a fast radio burst (FRB) from far beyond the Milky Way. Featuring interviews with the researchers behind the discovery itself, the story explores possible ways the defunct satellite could have produced such a remarkable burst of radio waves — which still remains a mystery.

Astronomers thought a mysterious radio burst came from deep space. It was actually a dead NASA satellite

6. A scientific conference with a veil of fear

Mona's piece is my top pick because of its timely and informative content and its narrative outline. She does a wonderful job describing the impacts of NASA's and the National Science Foundation's absences at a major astronomy meeting and connects it to wider issues concerning the scientific community at a time when many in their field feel uncertain about their academic and professional futures.

Mona plainly demonstrates the stakes from an easy-to-understand perspective, and shows the importance of such organizations at these kinds of biannual gatherings in a way that put me in the shoes of the disappointed scientists who traveled all the way to Alaska only for the headline act not to show up, and the scientists who eagerly await these meetings who were barred from attending.

I'd also like to add honorable mentions, though, to two other brilliant stories from this year: Daisy Dobrijevic's piece about visiting STARMUS in La Palma and Brett Tingley's about an Apollo-era radio telescope being up for sale.

NASA's been pulling out of major astronomy meetings — and scientists are feeling the effects

I went to STARMUS La Palma for science and music — I came back in love

This Apollo-era radio telescope in the NC mountains once spied on Soviet satellites. Now it's for sale

7. The division between our universe's most monstrous objects

Black holes and neutron stars are without a doubt the two most fearsome and impressive objects in the known universe. Both are born when massive stars die and "go nova." That means that the obvious question is: Where is the dividing line between these two bodies? It is so cool that we are on the verge of discovering that division, which will lead us toward figuring out what the biggest neutron stars are and what the smallest black holes are.

How compact can a neutron star get before collapsing into a black hole?

8. An industrial project threatening the world's largest telescope

My favorite stories this year are Tereza Pultarova's paired features on the threat posed to Cerro Paranal, published about a year apart. Together, they show how journalism can follow an issue beyond the initial alarm, tracing it through evidence, expert voices and ultimately a call to action. They balance the urgent need for clean energy with our shared responsibility to protect the night sky, highlighting not just obvious impacts to astronomy like light pollution but also subtler ones such as vibrations and turbulence. To me, this is one of the biggest emerging threats to modern astronomy — and exactly the kind of story we need to keep telling.

World's largest telescope threatened by light pollution from renewable energy project

An industrial project in Chile threatens Earth's darkest sky. 28 leading astronomers signed an open letter urging to move it

9. The hunt for alien life on Mars gets a lead

This story is a great example of how to cover the search for alien life responsibly. It highlights the inherent complexity and difficulty of the E.T. hunt without sucking the excitement out of important discoveries that spot the trail, like the Perseverance rover's "poppy seed" and "leopard spot" finds. All science journalists should seek to strike this balance.

Did NASA's Perseverance rover find evidence of ancient life on Mars? The plot thickens

10. The film "Apollo 13" is just as good as you remember

The quintessential space movie turned 30 this year, and Rich Edwards — one of our talented freelancers — looked back on Apollo 13 and how it showcased the grit and determination of NASA's scientists, and not just the rockstar astronauts onboard the stricken craft.

It's a beautifully written retrospective on a phenomenal movie, and if you missed it back in June, then it's time to perform a slingshot maneuver around the moon and check it out now.

'Apollo 13' at 30: The space movie where scientists have the right stuff too

11. The importance of journalism and a comet from beyond

I really enjoyed this story because I got a front row seat to see some of the coolest images of 3I/ATLAS in existence — and also because of the classic journalism spirit behind it. When this news broke, it was evening and just our astronomy editor Mona, myself, our video editor Steve, our spaceflight editor Mike and our editor in chief Tariq were on Slack, seeing these images together for the first time and tag-teaming to get the story polished and published. At one point, my internet (which I thankfully now have updated) wasn't working and I freaked out, fearing the job would reach a halt. Thankfully, the delay was short, and here we are.

So … long answer, but overall, not only is this story a joy to read because it's scientifically spectacular — look at those images of an interstellar object! — but also because of the people behind it. In a world where journalism and freedom of the press is under multiple threats, both from growing anti-intellectual culture and the rise of AI, it's important to remember people are at the heart of what we do.

NASA reveals new images of interstellar comet 3I/ATLAS from across the solar system: 'It looks and behaves like a comet'

We just got a great up-close look at a SpaceX Starlink satellite in orbit, thanks to Vantor's WorldView-3 spacecraft.

On Wednesday (Dec. 17), this particular Starlink suffered an anomaly that caused a loss of communication with the ground and an unscheduled venting of its propulsion tank. The satellite is now tumbling and headed down toward Earth’s atmosphere, where it will be incinerated in a matter of weeks, according to SpaceX.

SpaceX asked Vantor (previously known as Maxar Intelligence) to image the stricken satellite, to get a better understanding of its condition. And Vantor delivered.

The company used its WorldView-3 Earth-observing satellite to image the Starlink spacecraft on Thursday (Dec. 18) from a distance of 150 miles (241 kilometers).

The photo, taken while the duo were flying over Alaska, features a resolution of 4.7 inches (12 centimeters), providing SpaceX with key information about the satellite.

"Our team took advantage of the advanced capabilities of our non-Earth imaging technology and recently expanded collection capacity to move quickly and provide SpaceX with confirmation that their satellite was mostly intact," Todd Surdey, Vantor’s executive vice president and general manager of enterprise and emerging products, said in a statement on Saturday (Dec. 20). "This rapid intelligence delivery enabled them to quickly assess possible damage to the spacecraft."

There is apparently some damage: Data suggests that the satellite released a small number of debris objects as a result of the anomaly. But those pieces, and the satellite itself, shouldn't a present a problem to other spacecraft in low Earth orbit (LEO), according to SpaceX.

"We appreciate the rapid response by @vantortech to provide this imagery. Additional data suggest that there is a small number of trackable debris objects from the event, and we expect the satellite and debris to reenter and fully demise within weeks," Michael Nicolls, vice president of Starlink engineering at SpaceX, said in an X post on Saturday.

Starlink is by far the largest satellite constellation ever assembled. It currently consists of about 9,300 active spacecraft — about 65% of all the operational satellites in Earth orbit.

One of the world's largest Bitcoin mining facilities is seen leaking heat into the environment in a new image captured from orbit by a heat-seeking satellite that was recently released by the U.K.-based company SatVu.

The image reveals the thermal footprint of a major Bitcoin-mining data center in Rockdale, Texas, which has been widely criticized for its electricity consumption and carbon footprint.

SatVu didn't disclose which specific facility is in the image, but Rockdale is home to the Riot Platforms Bitcoin mine. The facility, considered the largest in the U.S., has an energy consumption of 700 megawatts, requiring about as much electricity as 300,000 homes.

The satellite image reveals in a resolution of 11.5 feet (3.5 meters) where and how much heat leaks into the environment from the plant. SatVu thinks that the insights that could be gleaned from such images could help regulators and grid operators better understand the impact such facilities have on the environment and local power networks.

"Today's data center buildout is moving incredibly quickly, and the world needs better ways to understand what's actually happening on the ground," Thomas Cobti, SatVu's VP for Business Development, said in a statement. "Thermal data gives an objective view of operational activity as it occurs — not weeks later through reports or announcements."

Although the image was only released on Dec. 17, it was most likely captured already in 2023, before SatVu's HotSat-1 satellites failed in orbit in December that year. SatVu plans to launch its replacement HotSat-2 next year and is already building HotSat-3.

The thermal camera aboard these satellites is the best in class, providing an order of a magnitude better resolution than other temperature-measuring devices in orbit.

SatVu released the first HotSat-1 images in October 2023, capturing the heat trails behind locomotives and showing how heat spreads from large sun-drenched concrete parking lots in a city like Las Vegas.

With the newly released image, the company shows how satellites could keep an objective eye on a fast-growing and controversial sector.

"At a closer level, [the image] reveals which substations and cooling systems are under load — clear, physical indicators of real operational behavior," the company said in the statement. "Together, these layers provide a grounded, evidence-based view of how major data center sites are evolving in real time."

A closer inspection of the image shows "distinct thermal signatures across rooftop chillers, transformers and electrical yards, making clear which parts of the facility are active and which remain dormant," SatVu added.

According to the McKinsey consultancy, investment into computing data centers will continue to grow, reaching more than $7 billion by 2030. Global data centers are believed to contribute by about 0.5% to the global carbon dioxide emissions. Bitcoin mining is especially energy intensive, a recent study estimated that one Bitcoin transaction generates about as much carbon dioxide as a gasoline car generates in a 1,600-mile (2,500-kilometer) drive.

A pair of companies are teaming up to provide customers with pioneering insurance for spacecraft specifically to cover space debris collision events.

Space insurance underwriters typically offer premiums that are mission-wide and include possible satellite replacement and can therefore be very expensive. California on-orbit services startup Arkisys is now teaming up with London-based Odin Space to offer its customers specific collision insurance, based on verified debris impact data from Odin Space's sensors.

Arkisys's upcoming Cutter mission will carry sensors from Odin Space, which is developing advanced space debris detection. Odin Space's Nano Sensors are designed to act as a "black box" for spacecraft, being able to pinpoint the exact moment of an impact to a spacecraft and its location. Forensic on-orbit data collected by the sensors can then be used to verify that a damaged spacecraft experienced an on-orbit impact event consistent with debris or micrometeoroid strikes.

Cutter is designed to host payloads or provide "last mile" transportation after launch, such as delivery to Arkisys Port modules in orbit. The new move aims to provide assurance to customers in an evolving and innovative space ecosystem amid the growing threat of space debris, without being prohibitively expensive.

"By enabling insurance for the Arkisys Port Architecture flight elements (Cutter and Port Modules) in orbit, this partnership offers customers not just a new on-orbit commercial logistics domain but a proven method to safeguard their business investments and operations," David Barnhart, CEO and co-founder of Arkisys, said in a statement.

"We see this partnership as one of the key enablers for the new in-space circular economy to enable thousands of new customers to develop new commercial innovations in space," he added. "We are proud to host Odin's unique new technology that enables this next step in space commercialization."

Odin Space is working to predict and monitor dangerous sub-centimeter orbital debris, which can't be tracked from the ground. Even such tiny pieces can do serious damage: Space debris travels at orbital speeds of roughly 4.5 to 5 miles per second (7 to 8 kilometers per second), with relative collision velocities of up to 9.3 miles per second (15 km per second), meaning any impact with a spacecraft will be highly energetic and potentially mission-ending. Earlier this month. the company secured seed funding of $3 million from investors, boosting its plans to track and map debris threats with its Nano Sensors and Scout Satellites.

"Our partnership with Arkisys marks a pivotal shift in how the industry tackles the rising threat of lethal, non-trackable debris," James New, CEO and Co-founder of Odin Space, said in the same statement. "Equipping Arkisys spacecraft with Odin's Nano Sensors is the first move in a new era of safer, smarter, more sustainable space activity."

Odin Space carried out its first orbital space junk tracking system test in 2023, hitching a ride on SpaceX's Transporter 8 mission.

One of SpaceX's Starlink broadband internet satellites suffered an anomaly in orbit on Wednesday (Dec. 17) and is now plunging toward Earth.

The mishap led to a loss of communication with the Starlink spacecraft, which was orbiting at an altitude of 260 miles (418 kilometers), according to the company.

In addition, "the anomaly led to venting of the propulsion tank, a rapid decay in semi-major axis by about 4 km [2.5 miles], and the release of a small number of trackable low relative velocity objects," representatives of Starlink, a company that's owned by SpaceX, said in an X post on Thursday morning (Dec. 18). That description suggests that the Starlink satellite's propulsion tank may have ruptured or suffered some other type of damage.

SpaceX is working with NASA and the U.S. Space Force to keep tabs on the newly liberated pieces of space debris, the post continued, stressing that there's not much to worry about.

"The satellite is largely intact, tumbling, and will reenter the Earth’s atmosphere and fully demise within weeks. The satellite's current trajectory will place it below the @Space_Station, posing no risk to the orbiting lab or its crew," Starlink representatives wrote.

"As the world’s largest satellite constellation operator, we are deeply committed to space safety," they added. "We take these events seriously. Our engineers are rapidly working to root cause and mitigate the source of the anomaly and are already in the process of deploying software to our vehicles that increases protections against this type of event."

The Starlink megaconstellation is by far the largest ever assembled. It currently consists of nearly 9,300 active satellites, meaning that SpaceX operates about 65% of all the functional spacecraft zipping around our planet.

And that number is growing all the time. SpaceX has launched 122 Starlink missions this year alone, sending more than 3,000 of the satellites to low Earth orbit.

Starlink satellites have a design lifetime of about five years, and SpaceX deorbits each one intentionally before it conks out in orbit.

The company has taken other steps to mitigate the space-junk threat posed by the megaconstellation as well. For example, Starlink spacecraft avoid potential collisions autonomously, an ability they put into practice quite often: In the first six months of 2025, Starlink satellites conducted about 145,000 evasive actions — an average of about four per spacecraft per month.

There's no guarantee that every satellite operator is quite so responsible, however. Last week, for example, a satellite recently deployed by a Chinese rocket gave a Starlink spacecraft a close shave, apparently without providing the proper warning ahead of time.

"As far as we know, no coordination or deconfliction with existing satellites operating in space was performed, resulting in a 200-meter close approach between one of the deployed satellites and STARLINK-6079 (56120) at 560 km altitude. Most of the risk of operating in space comes from the lack of coordination between satellite operators — this needs to change," Michael Nicolls, vice president of Starlink engineering at SpaceX, said via X on Dec. 12.

How long would it take for satellites to begin to collide with space junk and each other if they were to suddenly lose their ability to avoid each other?

A new study finds that, with the immense quantity of satellites that hurtle in Earth's orbit today, the first smashup would occur in less than three days, potentially triggering a dangerous collision cascade that could quickly make space around the planet unusable.

The study, published on the online preprint repository arXiv, has not yet been peer-reviewed, the authors caution, but it raises questions about the sustainability of humanity's use of space. The researchers call this expected time-to-collision value the Crash Clock and calculated it by running a model of all known objects in space and determining an average collision rate for various orbital regions in the absence of avoidance maneuvers.

They found that regions in low Earth orbit (LEO) at altitudes around 300 miles (500 kilometers), where most satellites of megaconstellations like SpaceX's Starlink reside, could see a collision in as little as 2.8 days. For comparison, the team ran an identical simulation with numbers of satellites and space debris in orbit from 2018. At that time, it would have taken 128 days for the first collision to occur, Samantha Lawler, an associate professor in astronomy at the University of Regina in Canada and one of the paper's authors, told Space.com.

"It's been a big change since 2018," Lawler said.

The idea that satellites in orbit could suddenly lose their ability to avoid collisions is not science fiction. Every time the sun unleashes a coronal mass ejection (CME) — a burst of magnetized plasma — toward Earth, the planet's tenuous upper atmosphere thickens. Satellites in LEO then experience more drag and slow down, meaning their trajectories become impossible to predict.

In 2003, for example, after the Halloween storm — one of the most intense space weather events of the last three decades — satellite operators lost track of positions of their spacecraft for days. At that time, a few hundred operational satellites orbited the planet, and no collision occurred. And the Halloween storm was only a fraction of what the sun is capable of. A stronger solar storm, perhaps as potent as the Carrington Event of 1859 — the most intense recorded solar storm in human history — would take a week or more to fully subside.

"At the beginning of a solar storm, there's a huge increase in atmospheric density and things start to get pulled down," Sarah Thiele, an astrophysics researcher at Princeton University, and corresponding author of the paper, told Space.com. "Before things start getting back to normal, you have uncertainties of several kilometers in the positions of satellites, and it becomes impossible to estimate where objects are going to be in the future — and therefore it becomes impossible to predict collisions and conduct avoidance maneuvers."

The Crash Clock data suggests that, in 2018, near-Earth space would most likely have had enough time to recover from the most extreme solar storm before the first collision occurred. In 2025, however, an orbital smashup would be almost certain. Such a collision would create thousands of fragments that would threaten everything in their path, potentially triggering an unstoppable chain of events. With every subsequent crash, the affected orbital region would become more unsafe — a nightmare scenario known as the Kessler syndrome.

"2.8 days is the average expectation value for time to the first collision," Thiele said. "It's a probabilistic estimate. We're not saying that for sure this is going to happen in exactly that time. It's what you might expect."

Currently, some 13,000 functioning satellites orbit the planet, according to the European Space Agency, together with more than 43,500 pieces of space debris — defunct satellites, rocket stages and collision fragments — that are large enough to be tracked. These objects circle the planet at speeds of about 7.8 kilometers (4.8 miles) per second, and their paths frequently intersect. Space situational awareness companies, the U.S. Space Command and other agencies predict satellite trajectories and alert operators to perform collision-avoidance maneuvers in case of close approaches. Starlink, by far the currently largest constellation in orbit, encompassing around 9,000 functioning satellites, performed 145,000 collision-avoidance maneuvers in the six months prior to July 2025, equivalent to around four maneuvers per Starlink satellite every month.

The global space industry, however, is far from done with satellite constellation deployments. Analysts estimate that by 2035, tens of thousands more satellites might be added to Earth orbit. Things might therefore become much more treacherous in the not-so-distant future.

Lawler and Thiele declined to estimate how short the Crash Clock could be if there were perhaps six or 10 times as many satellites in Earth's orbit as there are today.

They say the satellite operators can, to a degree, improve their chances to survive solar mayhem by quickly de-orbiting old satellites and carefully considering how many spacecraft to launch to certain altitudes.

"The part that satellite operators can control is the number of satellites and the density of satellites," said Lawler.

Thiele added that the study highlights how fragile the space environment has become in a few short years.

"The Crash Clock demonstrates how reliant we are on errorless operations," she said. "If everything works as it's supposed to all the time, then we're okay."

Sooner or later, however, another Carrington-size solar storm will hit. Whether satellite operators will be ready for it remains a question. In 2025, the number of global space launches exceeded 300 for the first time in history, and the industry shows no signs of slowing down.