NASA’s Swift boost mission ends without raising observatory’s orbit

NASA’s attempt to raise the orbit of its Neil Gehrels Swift Observatory has ended without a boost, leaving the aging science spacecraft on a declining path. NASA said on September 28 that the robotic LINK spacecraft, built by Katalyst Space for the attempt, re-entered Earth’s atmosphere on September 25. Control problems had already led the partners to abandon the planned capture of Swift. The result matters because Swift has spent more than two decades observing cosmic explosions, and atmospheric drag is steadily pulling it lower.

NASA formally ended its involvement in LINK’s mission on September 3. Katalyst said LINK operated in orbit for 85 days after its July 3 launch. Its intended job was to meet Swift, grapple a spacecraft that was never designed to be serviced, and lift it into a longer-lasting orbit. That final step did not happen; the partners instead used the remaining mission to test spacecraft systems and gather data.

How the boost attempt unraveled

After LINK reached orbit, NASA reported intermittent losses of communication and trouble controlling its orientation. Katalyst’s account gives a more detailed sequence: an electrical power-system fault made two of LINK’s three reaction wheels unavailable, and the spacecraft entered a spin around multiple axes. Reaction wheels normally help a spacecraft control where it points without relying continuously on propellant.

Katalyst said its engineers restored limited control with the remaining reaction wheel, reaction-control thrusters and updated flight software. Hall-effect thrusters reduced LINK’s rotation rate from 9 degrees per second to 1.47 degrees per second, according to the company. The recovery kept the spacecraft operating, but using thrusters to manage its orientation consumed propellant quickly. NASA and Katalyst concluded that too little fuel remained to safely capture Swift and raise its orbit.

What LINK did in orbit

The partners changed the mission to focus on proximity operations and equipment tests. Katalyst said LINK passed within 12 to 15 kilometers of Swift and collected imagery, though the observatory was not resolved in those images. Space.com reported the close approach earlier in September. Katalyst also said it exercised all three robotic arms, tested their movement and grippers, and gathered data from spacecraft systems while investigating the anomalies.

Katalyst described the work as a foundation for its NEXUS spacecraft platform and future robotic missions. NASA’s astrophysics director, Shawn Domagal-Goldman, said the effort offered lessons in satellite servicing, rapid mission development and operating spacecraft to extend their time in low Earth orbit. Those are the partners’ assessments of what they learned. The available accounts do not establish how much the LINK data will improve a later servicing mission.

The schedule itself was unusual. NASA contracted Katalyst in September 2025, and the company says it designed, built, tested and launched LINK within nine months as part of a $30 million mission. Swift had no standard docking interface, so LINK would have had to approach and manipulate a larger spacecraft without the hardware normally provided for servicing. Katalyst chief executive Ghonhee Lee acknowledged that the company did not achieve every objective, while saying its flight experience would inform future work.

Swift’s remaining time

Swift launched in November 2004 to study gamma-ray bursts and went on to observe other phenomena, including flares from distant black holes. Spacecraft in low Earth orbit lose altitude to atmospheric drag; NASA says increased solar activity made that loss faster for Swift. The agency had identified about 185 miles, or 300 kilometers, as an altitude below which a boost attempt would become increasingly difficult. Its September 28 account says predictions had placed that threshold in fall 2026.

To buy time for LINK, Swift’s controllers changed where the observatory pointed. NASA said they replaced about a quarter of its science targets with lower-drag pointing directions in December 2025 and had fully adopted that approach by February. The restrictions meant Swift was not making pointed science observations from mid-February to late August. Space.com reported that two of its three science instruments were switched back on in late August after the boost plan was dropped.

NASA’s September 28 report gives no revised date for Swift’s re-entry. Domagal-Goldman said that without intervention the observatory was expected to re-enter by year’s end, but the precise timing remains uncertain in the published accounts. For now, the failed boost leaves Swift’s remaining observing time dependent on its declining orbit, while NASA and Katalyst assess what LINK’s abbreviated flight can contribute to later servicing attempts.