NASA abandons Swift rescue after LINK fails: $30 million, no boost

The Neil Gehrels Swift Observatory is going to burn up. NASA and Katalyst Space Technologies said on Wednesday, August 19, that the robotic rescue mission known as LINK will not capture and boost the falling gamma-ray telescope, according to Ars Technica. The observatory has been in low Earth orbit since 2004 and should reenter the atmosphere later this year.

LINK launched on July 3 aboard Northrop Grumman's Pegasus XL rocket.

The plan was ambitious. Katalyst, an Arizona-based startup, won a $30 million contract less than a year before launch, Ars Technica reported. It had nine months to design, build and launch a spacecraft about the size of a refrigerator. The craft carried three robotic arms and three xenon-fueled electric thrusters. It was meant to grab Swift and lift it to a higher orbit over several months. NASA said the launch had to happen by this summer to reach Swift before atmospheric drag pulled it down for good.

Everything seemed to go well for the first few weeks in orbit. Then, in late July, LINK spun out of control. NASA said on July 28 that the spacecraft's attitude control systems had malfunctioned, causing it to rotate at about 9 degrees per second and producing sporadic communications, according to NBC News. Ars Technica reported that two of the satellite's three reaction wheels, used for attitude control, stopped working, and that cold gas thrusters for finer pointing also had issues. That left the three low-impulse plasma thrusters as the only way to regain control as LINK zipped around Earth at nearly 5 miles per second.

Mission managers did slow the spin this month, but not enough. In a LinkedIn post, Katalyst said the company and NASA had agreed that "the mission will not include the capture and boost of NASA's Neil Gehrels Swift Observatory."

"Katalyst designed, developed, and launched an experimental spacecraft to go after an ambitious mission on an aggressive timeline," said company CEO Ghonhee Lee in the LinkedIn post. "We took on this high-risk, high-reward challenge and are proud of the milestones we reached along the way."

NASA administrator Jared Isaacman acknowledged the outcome is not what was hoped for. "This is not the outcome we were working toward, but it does not change why this mission was worth attempting," he said in a statement. Shawn Domagal-Goldman, director of NASA's astrophysics division, called it "a first-of-its kind attempt, developed on an unprecedented timeline driven by the Sun's activity."

The Sun is the reason Swift was in trouble. All satellites in low Earth orbit slowly lose altitude because of atmospheric drag, NBC News reported. During a period of intense solar activity in 2024, the Sun heated Earth's atmosphere, increasing drag and causing Swift's orbit to decay faster than anticipated. Swift has no thrusters of its own to maintain orbit, so a rescue like LINK was the only way to keep the $500 million observatory going, according to Ars Technica.

Swift was designed to study gamma-ray bursts, the most powerful explosions in the known Universe, triggered by events such as the births of black holes and collisions between ultra-dense stars. Its combination of multi-wavelength instruments and agile pointing let it locate bursts for follow-up observations by other observatories. It far outlived its original two-year design, and its loss will leave a gap in high-energy astronomy that is unlikely to be patched soon.

Katalyst is not abandoning LINK. The company said it will try to approach and rendezvous with the spacecraft to conduct technology demonstrations for future flights. The rendezvous sensors and robotic arms used by Katalyst are seen as vital technologies for satellite servicing, a field where several US companies are working on missions that could eventually refuel, repair or upgrade satellites.

"We have already learned a tremendous amount, and now our job is to turn those lessons into something durable, building a repeatable playbook to inform future rendezvous and proximity operations and satellite servicing," Lee said.