Rocket Lab launched its 21st and final mission of the year over the weekend, sending a private Japanese Earth-observing satellite to orbit.

An Electron rocket carrying the QPS-SAR-15 satellite, nicknamed Sukunami-I, lifted off from Rocket Lab's New Zealand site on Sunday (Dec. 21) at 1:36 a.m. EST (0636 GMT; 7:36 p.m. local time in New Zealand).

The launch, which the company called "The Wisdom God Guides," went well: Electron's "kick stage" deployed Sukunami-I into a circular orbit 357 miles (575 kilometers) above Earth as planned.

Once it's up and running, the satellite will join the Earth-observing constellation operated by Japanese company iQPS. Its spacecraft view our planet using synthetic aperture radar, meaning they can peer through clouds and get good looks at night as well as during the day.

"The Wisdom God Guides" was Rocket Lab's sixth launch in 2025 for iQPS and its seventh for the company overall. And the Japanese company has booked an additional five Electron launches in 2026, according to Rocket Lab.

Sunday's flight was the last of the year for Rocket Lab. It has now launched 21 missions in 2025, adding to the company's single-year record. The previous high, set last year, was 16.

All of this year's launches were successful. Eighteen were orbital launches with the 59-foot-tall (18-meter-tall) Electron. The other three involved HASTE, a modified, suborbital version of Electron designed to let customers test hypersonic technologies in the final frontier.

"Our new record of annual launches and the breadth of upcoming missions go to show how much of a global impact Electron continues to have on the space industry, and we're looking forward to another year of continued execution in 2026," Rocket Lab founder and CEO Peter Beck said in an emailed statement on Sunday.

"In 2026, we're expanding Electron’s global reach with more multi-launch constellation deployments, dedicated missions for domestic civil space and international space agencies in Japan and Europe, and both suborbital and orbital launches with defense applications for hypersonic technology and national security," he added.

Rocket Lab launched a new type of satellite for the U.S. Space Force early Thursday morning (Dec. 18).

An Electron rocket carrying four "DiskSats" lifted off from Rocket Lab's pad on Wallops Island, Virginia on Thursday at 12:03 a.m. EST (0503 GMT).

The launch, which Rocket Lab called "Don't Be Such a Square," kicked off the Space Test Program (STP)-S30 mission for the U.S. Space Force's Space Systems Command.

STP-30 will operate the first-ever DiskSats, a new type of spacecraft developed by The Aerospace Corporation with funding help from NASA. At 40 inches wide by just 1 inch thick (102 by 2.5 centimeters), each DiskSat has the approximate dimensions of a manhole cover.

That odd shape could lead to greater performance in the final frontier for small satellites, which have traditionally employed the boxy "cubesat" form factor.

DiskSats "could offer more power and surface area for instruments, providing more opportunities for NASA to expand upon target mission objectives for small spacecraft," agency officials wrote in a description of the new tech.

"With its ability to fly continuously with one face pointing at the Earth, the DiskSat can also have a very low drag, making them capable of very-low-altitude missions (less than 300 kilometers or 185 miles) such as those necessary for some Earth-observation missions," NASA added.

The DiskSats won't be flying so low on their inaugural mission, however. The Electron deployed the quartet at an altitude of 342 miles (550 km) about 55.5 minutes after launch as planned, according to Rocket Lab.

Rocket Lab initially planned to launch "Don't Be Such a Square" in April 2026 but expedited it at the Space Force's request, the company said in an emailed statement.

The mission was Rocket Lab's 20th of 2025, extending the company's single-year launch record. The previous high was 16, set in 2024. Most of these have been orbital flights of the 59-foot-tall (18 meters) Electron, which gives small satellites dedicated rides to Earth orbit. But three were suborbital missions conducted by HASTE, a modified version of Electron that lets customers test hypersonic technologies in the space environment.

Editor's note: This story was updated at 2:18 a.m. ET on Dec. 18 with news of successful launch and satellite deployment.

Update for 8:30 a.m. ET on May 10: Kosmos 482 has fallen harmlessly into the Indian Ocean west of Indonesia, according to according to Russia's space agency Roscosmos.

In 1972, the Soviet Union launched the Kosmos 482 lander, a spacecraft designed to reach Venus and land on its surface. The craft never reached Venus, however. The rocket that launched it suffered an anomaly, stranding the probe in an elliptical orbit around Earth where it has remained for over 50 years.

That five-decade stay in space could come to an end today. Kosmos 482 is expected to reenter Earth's atmosphere and possibly crash somewhere on the surface of the planet. The probe consists of a 3.3-foot-wide (1-meter-wide) titanium shell lined with thermal insulation, designed to withstand the heat of entry into Venus' atmosphere. The craft weighs about 1,190 pounds (495 kilograms).

It's still quite uncertain just where and when the craft will fall, although it is expected to reenter at 2:37 a.m. ET (0637 GMT) on May 10 +/- 3.28 hours, according to the European Space Agency. Based on current tracks and the dead probe's orbital inclination of 52 degrees, the craft's reentry could occur anywhere between 52 degrees north latitude and 52 degrees south — an area that covers most of Earth's surface.

However, the reentry of Kosmos 482 might not be as dangerous as other space junk falls. "As it will likely reach earth surface as only one single object, the risks involved are lower than for example those created by a Falcon 9 upper stage reentry, which showers multiple meter-sized objects over a large area," Dutch satellite tracker Marco Langbroek wrote in a blog post tracking the reentry of Kosmos 482.

But there's no need to fear being struck by the falling probe, according to CORDS. After all, 71% of Earth's surface is covered in water, and much of the land on the surface is unpopulated. The odds are that the probe will land somewhere harmless.

"While the risk is nonzero, any one individual on Earth is far likelier to be struck by lightning than to be injured by Cosmos 482," according to The Aerospace Corporation. "If it remains intact all the way to the surface, we project a risk of 0.4 in 10,000 — which falls well within the current safety threshold."

Satellite trackers and astronomers have been tracking Kosmos 482 for years. In 2019, there were reports that the craft might fall within a year, which didn't happen. Astrophotographer Ralf Vandebergh of the Netherlands has been capturing the probe on camera for over a decade, and recently captured imagery suggesting its parachute might be out while it circles Earth.

Some experts have cast doubt on that speculation, however. Langbroek writes that the 'tail'-like structure in Vandebergh's photos is likely the result of "camera/telescope shake and atmospheric distortion" instead of a parachute.

Kosmos 482 was part of the Soviet Union's historic Venera program of Venus exploration, which landed the first probe on the planet's surface in 1970 with the Venera 7 craft, and later sent back the first color pictures of Venus' surface in 1982 with the Venera 13 probe.

Stay up to date with the reentry of Kosmos 482 with ESA's live blog or Marco Langbroke's website SatTrackCam.

All those eye-catching, arguably clickbait headlines of bringing home stranded astronauts stuck in space underscores a worrisome reality: The United States lacks a "go get 'em" capability for in-space rescue.

The lessons of Apollo, Skylab and the space shuttle, with respect to the rescue of astronauts in space, appear to have been forgotten.  That memory lapse comes at a time when more folks, from a variety of nations, are flying into space than ever before, many tucked inside commercially built spacecraft. 

The recent incident involving the first crewed flight of Boeing's Starliner spacecraft, which suffered thruster issues and helium leaks, is a case in point. And Starliner's mission was a relatively simple one — go up to the International Space Station and back. Private crews have done even gutsier things — conducting a high-altitude spacewalk without an airlock, for example. And they'll continue to up the ante in the near future, rocketing into polar orbit around Earth and even heading off to the moon. 

Sense of urgency

"The present posture of not planning for in-space rescue and not having responsive in-space rescue capabilities needs to be addressed before the need for a rescue materializes … not after. The U.S. has the wherewithal to establish space rescue capabilities and to do so with a sense of urgency."

Related: 'Space Rescue Service' needed for coming space tourism era, report argues

That's the view of Grant Cates, a senior project leader for the space architecture department at The Aerospace Corporation. He's also a key team member of the organization's Space Safety Institute.

This past February, on the 21st anniversary of the space shuttle Columbia disaster, The Aerospace Corporation and the think tank RAND brought together industry and government specialists, putting them in a collaborative workshop setting. 

The intent was to develop a long-term vision for space rescue and set forth next steps to making it a reality. The two groups have also held in-space rescue sessions at the Accelerating Space Commerce, Exploration, and New Discovery (ASCEND) gatherings held by the American Institute of Aeronautics and Astronautics.

Fall into the gap

"The industry today has, I believe, the capabilities to put in place similar capabilities like we put in place after the shuttle Columbia tragedy to have a rescue capability," Cates told Space.com. 

"We have multiple launch pads, multiple launch vehicles and multiple crew-capable vehicles. But we have a gap. We're not planning to do it, and you can't do a rescue on the fly. You have to plan ahead of time," Cates said.

Until the last two years, in general, the topic of space rescue hasn't been discussed much, said Jan Osburg, a senior engineer at RAND. There is a gap, he added — "no mandate, especially for in-space rescue."

Osburg said there's a need for objective analysis before determining the optimum way forward. "I'm personally not convinced that it has to be U.S. government," he told Space.com. "But that remains to be seen."

There is consensus in the community of those looking into in-space rescue that there is, indeed, a gap. "But there is a need, and something needs to happen," Osburg said. "But there has been no agreement on what exactly should happen."

Quick, small and simple

While a plan for saving space travelers in trouble remains in limbo land, the idea of something quick, small and simple, such as a study office with a few people, is viewed as a feasible next step to scope out in-space rescue details, Osburg said.

It would take just a modest amount of money to get that ball rolling. 

"That's really peanuts, given the amount of money involved in space overall and also given the amount of damage that could be done if something serious were to happen," said Osburg.

Related: 20 years after Columbia shuttle tragedy, NASA pledges 'acute awareness' of astronaut safety

Mitigate catastrophe 

Cates of The Aerospace Corporation senses an industrial-strength possibility.

"There's nothing that prevents industry from taking voluntary actions. I believe that they have the capability today to put in place at least a modest partial rescue capability to help mitigate some of the risks going forward," said Cates.

"Ultimately, I think we need congressional legislation to authorize an agency of the federal government to take the lead in in-space rescue," Cates said. "And then appropriate some amount of funding to make that happen. Right now, we don't have that."

Cates added that not all situations that might transpire in space are going to be helped by rescue. 

"You may lose the crew and the vehicle so rapidly that nothing could be done," Cates said. "The crew has to be alive. There has to be some amount of time in which we could actually do the rescue. The key to avoiding those is to mitigate the chances of those catastrophes in the first place."

International goodwill

Late last year, Osburg contributed to a RAND policy report on space concepts for the new space era, highlighting the design of a space rescue service, or SRS. 

In that appraisal, Osburg noted that experience on Earth has shown that crew rescue in extreme environments is one area in which competitors can find common ground. 

Osburg pointed to the establishment of the International Submarine Escape and Rescue Liaison Office. That organization was set up to provide international coordination and response for a distressed submarine.

Osburg's bottom line is this: "A well-designed SRS could greatly reduce the risk associated with human spaceflight missions and thus ultimately encourage the expansion of humanity into space. The country or countries establishing such a capability would not just be able to accrue international goodwill and other reputational benefits, they will also have a greater opportunity to shape space exploration and use for the foreseeable future." 

Does the spaceflight industry need an agreed-upon unit of measurement for space-bound cargo? A nonprofit called The Aerospace Corporation thinks the answer is yes, and it's assembled a working group to come up with a standard "launch unit." 

As technological advances make it possible to pack more satellite capabilities into increasingly smaller packages, the number of companies, universities and other institutions trying to send satellites into space is increasing. But most of those small payloads still have to hitch a ride with larger payloads. The Aerospace Corporation thinks organizing those "rideshares" based on a standard unit for payload size would make it easier to put more payloads into space, and make it possible to add small payloads to a launch on short notice. 

"Developing a standard Launch Unit, or Launch-U, for mid-sized smallsats — approximately the size between a toaster and a small refrigerator — will enable rideshares to be configured more quickly and efficiently, resulting in more launch opportunities at a lower cost," Aerospace representatives said in a statement. "Aerospace [Corporation] is driving the Launch-U conversation by assembling representatives from industry, academia and government to set the mid-size smallsats standard." [In Photos: Tiny Satellites Launch from Space Station]

Hitching a ride to space

While there are a few companies trying to make small rockets that can make dedicated trips to space for small payloads, rocket ridesharing is likely to continue, experts say. Large rockets, like those produced by SpaceX and United Launch Alliance, can carry thousands to tens of thousands of pounds of cargo. That typically means they carry one large, primary payload, and then let customers with smaller payloads buy the remaining space. 

"This has worked well, but it provides a very mission-unique solution," Carrie O'Quinn, a senior project engineer for The Aerospace Corporation, told Space.com in an email. The launch provider and the company (or group) providing the smaller payload work together to figure out how the smaller payload will fit on board and how it will be deployed or reach its destination, she said. 

"However, now the secondary small satellite is married to that mission," O'Quinn said. "If the primary satellite is delayed or the launch vehicle has a failure, the launch of the secondary small satellite will be delayed until those issues are resolved. If the small satellite has development issues and is delayed, they may miss their launch opportunity and will have to start the process all over again with another launch vehicle."

What if, instead, the small-satellite provider simply had to make sure its payload fit inside a box with a pre-established volume, similar to the way standardized shipping containers are used to send cargo across oceans? The launch provider could announce to the community that a spot — equal to a certain number of units — was open on the vehicle. 

"If the small satellite and the launch vehicle interfaces are built to the Launch-U standard, the small satellite can look for another ride which meets its requirements, and the original mission can also look for a new match that meets the Launch-U standard," O'Quinn said. 

By eliminating the specialized pairing of small payloads and particular rocket launches, providers could also get small payloads aboard rocket launches on much shorter notice than what is currently possible, Aerospace representatives said. And, adding more customers to each launch could reduce the cost per customer.  

The cubesat model

There is already a standard unit for miniature satellites called cubesats: A 1U cubesat is 10 centimeters (about 4 inches) on each side. People wishing to send satellite technology or experiments to space can build those things into a satellite with the standard cubesat size (or whole multiples of that size); the 10x10x10 cm cubesats can then be packed together in a maximally efficient manner, as opposed to trying to pack together satellites of varying sizes and shapes. 

"The CubeSat definition standardized the launch interface, and defining intermediate smallsat classes with Launch-U could have a similar revolutionary impact on the space industry," company representatives said in the statement. The creation of the Launch-U working group began with a "hack session" involving a group of people discussing ways to tackle difficult problems in the spaceflight industry. "The premise for the Launch U was: 'Why can't I get a slot and launch tomorrow?'" Randy Villahermosa, executive director of innovation at The Aerospace Corporation, said in an email. "During the Hack Session, we learned that the CubeSat 1U form factor was not ideal for launch vehicles. That led to the concept of creating a comparable unit for launch."

The Aerospace Corporation has established a working group that consists of "representatives from industry, academia and government," according to the statement. Villahermosa said the group has "pulled together inputs from across the industry (launch vehicle providers, satellite developers, integrators and aggregators, as well as government and academia) to develop a rough draft of the standard.

"We have an aggressive timeline that we're hoping to have a draft to industry in the spring for comments," he continued. "Ideally, we'd like to present the results at next August's 2018 SmallSat conference." 

Representatives from The Aerospace Corporation said they've received a positive response from the small-satellite community, but for the Launch-U initiative to work, large-scale launch providers will also have to participate. 

Eric Stallmer is president of the Commercial Spaceflight Federation (CSF), a member organization that represents more than 70 spaceflight companies. Part of CSF's mission is to "[lay] the foundation for a sustainable space economy and [democratize] access to space for scientists, students, civilians, and businesses."

After talking with some CSF members about the proposal, Stallmer said he thinks there "generally seems to be support for it" and that those members appreciate that Aerospace has brought in representatives from all sides of the launch industry into its working group. 

At the same time, Stallmer said he doesn't think large launch providers were necessarily seeking this type of standardization for small to midsize payloads; the need for this standardization lies mostly with the small-payload providers. But the general trend of shrinking satellites means there's a business incentive for launch providers to pay attention to the proposal now that it's been brought to their attention, he said. 

"I think it's a good, innovative look at how to make the launching aspect of things or the payload a little more efficient," Stallmer said. "We're always intrigued by that."

Follow Calla Cofield @callacofield. Follow us @Spacedotcom, Facebook and Google+. Original article on Space.com.