It's getting to be crunch time for a groundbreaking satellite-rescue mission.
A private spacecraft called "Link" is set to lift off late next month to meet up with NASA's Neil Gehrels Swift Observatory, which launched to low Earth orbit (LEO) in 2004 to hunt for powerful space explosions known as gamma-ray bursts.
Swift is still working just fine. But atmospheric drag is pulling it down at an ever-increasing rate, and the telescope is powerless to resist; it doesn't have a propulsion system. Link will be the scope's savior, if all goes to plan, meeting up with Swift in LEO and boosting it to a higher altitude.
This plan is bold and unprecedented. Link, built by Arizona-based Katalyst Space Technologies, aims to become the first private spacecraft ever to capture a robotic satellite operated by the U.S. government.
Doing so will not be easy, especially since it's unclear where exactly Swift will be in the coming months. That's because Earth's atmosphere — and therefore the drag it imposes on orbiting spacecraft — is not static. Our blanket of air expands when the sun is active and contracts during times of solar quiescence.
Solar activity waxes and wanes on an 11-year cycle, the most recent of which peaked in 2024. That intense round of space weather put the Swift team on notice: Modeling work performed in early 2025 predicted that the telescope would reenter the atmosphere by the summer of 2026.
That dire prognosis laid the groundwork for Link's rescue mission, which NASA funded via a $30 million contract with Katalyst. The modeling work has continued, too, as NASA and the company flesh out their "fast-paced plan" to raise Swift's orbit.
"These predictions evolve over time, based on space weather forecasts and other factors like Swift's current height and orientation," Michael Shoemaker, deputy flight dynamics lead in SSMO (Space Science Missions Operations) at NASA's Goddard Space Flight Center in Greenbelt, Maryland, said in a May 26 statement.
Shoemaker and his team aren't doing this just for Swift; they make such predictions for a variety of satellites, both active and defunct. Their models incorporate a wide range of data, including details from each satellite team, tracking information collected by the U.S. Space Force and solar activity research from NASA and the National Oceanic and Atmospheric Administration's Space Weather Prediction Center.
Shoemaker and his colleagues are now generating weekly orbital predictions for Swift, which the mission team has used "to make decisions about when to halt science observations and how to steer the spacecraft to reduce drag as much as possible," NASA officials said in the same statement.
"This innovative new approach to operating Swift has allowed them to successfully slow its orbital decay," they added.
As a result, Swift will likely stay at least 185 miles (300 kilometers) above Earth — the "critical altitude" giving Link's orbit-boosting mission the best chance of success, according to NASA — into early fall.
That's good news, but the modeling team still has work to do.
"We're also working on predictions for where Swift will be when Link is set to launch in June aboard a Northrop Grumman Pegasus rocket," Russell Carpenter, the deputy project manager in SSMO, said in the same statement.
"The project to re-boost Swift has generated intense interest across the flight dynamics community," he added. "The Swift team is grateful that so many people have been willing to pitch in to help with refining these predictions."
