NASA launches first-ever mission to save ageing Swift observatory from falling to Earth

WASHINGTON — The first-of-its-kind mission to extend the life of one of NASA’s longest operating space observatories is underway with the launch of a commercial robotic spacecraft to catch up to and push the ageing Neil Gehrels Swift Observatory into a higher orbit.

If successful, it would be the first time a commercial robotic spacecraft captured and serviced a NASA satellite that was never designed to be serviced in orbit.

The Neil Gehrels Swift Observatory, which has spent nearly 22 years observing some of the universe’s most energetic phenomena at multiple wavelengths of light, is losing altitude due to atmospheric drag. NASA said increased solar activity has sped up the spacecraft’s orbital decay, putting it at risk of re-entering Earth’s atmosphere later this year unless its orbit is boosted.

Engineers at Penn State University's Eberly College of Science, which runs the observatory, have cut the power draw of the spacecraft and changed its orientation to reduce drag and slow its descent. NASA calculates that reentry is increasingly likely when Swift’s altitude drops to less than about 185 miles (300 kilometres).

NASA, staring at the loss of the observatory years ahead of schedule, solicited proposals from industry to construct a rescue mission. “This was no ordinary spacecraft,” Shawn Domagal-Goldman, director of the Astrophysics Division at NASA, said at a news conference in June. He said Swift continues to offer scientific capabilities for which there is no direct replacement.

In September 2025, NASA picked Arizona-based Katalyst Space Technologies, which had nine months to build, test and launch a spacecraft to rendezvous with Swift and boost its orbit.

The company's robotic satellite, called LINK, launched Friday atop a Northrop Grumman Pegasus XL rocket. The air-launched rocket was released from the company’s modified L-1011 aircraft, Stargazer, at an altitude of about 40,000 feet (12,000 metres) over the Kwajalein Atoll in the Marshall Islands before firing its engines and placing LINK into orbit in step with Swift’s trajectory.

The launch came after a series of delays caused by bad weather and a software problem that led to the cancellation of an earlier launch attempt. NASA and Katalyst later confirmed that ground controllers were able to contact the spacecraft after it achieved orbit.

The mission has now entered the toughest phase. LINK will be performing system checks over the next few weeks before it gets closer to Swift. The spacecraft will use navigation sensors and three robotic arms to scan the observatory for suitable attachment points and attempt to grab it.

If the docking works, LINK will slowly raise Swift’s orbit from about 185 miles (300 kilometres) to about 370 miles (600 kilometres), potentially adding years to the observatory’s life.

Domagal-Goldman said the mission has already exceeded expectations by getting into orbit, given the technical risks.

Why Swift Must Be Saved

In low-Earth orbit, atmospheric drag gradually lowers the altitude of spacecraft. The effect is more pronounced during periods of increased solar activity, when energy from the Sun causes the Earth’s upper atmosphere to expand.

NASA says the recent solar maximum — the peak of the Sun’s roughly 11-year activity cycle, reached in 2024 — has greatly increased atmospheric drag on Swift, accelerating its orbital decline.

NASA chose to extend the mission to retain valuable science capabilities and demonstrate technologies that could support future satellite servicing and long-term space operations, while the observatory could have been permitted to re-enter Earth’s atmosphere naturally.

Swift was not built to be serviced,' Ghonhee Lee, CEO of Katalyst Space, said in a NASA statement. “We are developing a blueprint for how to service spacecraft that were never meant to be maintained in orbit by showing that we can extend their lifetime quickly and cost-effectively.”

LINK weighs about 880 pounds (399 kilograms) – one-third the mass of Swift – and has about 20 feet (6 metres) of solar panels and three robotic arms.

LINK will take a close look at the observatory to determine the best and safest places to attach itself before attempting to capture it. Engineers say the spacecraft’s thermal insulation may have shifted or degraded after more than two decades in orbit, making an in-depth survey critical before any attempt to dock.