A three-armed spacecraft called LINK lifted off from a Pacific atoll on Friday aboard an air-launched Pegasus rocket, initiating an unprecedented attempt to salvage a major space observatory. The mission, funded by NASA at a cost of $30 million, targets the Neil Gehrels Swift Observatory, a gamma-ray-burst hunter that has been slowly sinking toward Earth and would otherwise burn up in the atmosphere by October. The launch, delayed by weather and a technical glitch, places the rescue craft on a trajectory to rendezvous with Swift in roughly one month.

Swift was launched in 2004 into an orbit of about 600 kilometres, but it now circles at roughly 360 kilometres after two decades of atmospheric drag. The decay accelerated sharply in the past two years because heightened solar activity has expanded the upper atmosphere, increasing friction on the satellite. The observatory carries no propulsion system of its own, having been designed for a two-year mission that was repeatedly extended. Without intervention, mission controllers in the United States had projected a destructive re-entry before the end of 2026, a timeline that forced a compressed development schedule.

Katalyst Space Technologies, an Arizona startup, designed, built and tested the LINK spacecraft in just eight months under a fixed-price contract. The robot, roughly the size of a refrigerator, will spend several weeks checking its systems before closing in on Swift. Using cameras and sensors, it will circle the telescope to assess its condition, then extend three robotic arms to grasp a structural flange. Once attached, low-thrust ion engines will slowly raise the observatory by about 240 to 300 kilometres over the course of at least a month, restoring it to an altitude where it can resume scanning the cosmos for gamma-ray bursts and other high-energy transients.

Scientists on both sides of the Atlantic describe the mission as high-risk but worth attempting. Bradley Cenko, Swift’s principal investigator at NASA’s Goddard Space Flight Center, called the observatory a “multi-tool” for studying the universe, while Simeon Barber, a planetary scientist at the UK’s Open University, noted that the telescope enables study of super-high-energy phenomena for which no other instruments exist. NASA officials have indicated that a similar salvage operation could be considered for the Hubble Space Telescope, which is also losing altitude. The immediate milestone is the rendezvous: LINK must locate and approach a moving target that was never designed to be captured, a manoeuvre expected to unfold over the next four to six weeks.