A $30 million mission to save one of NASA's most productive space telescopes from burning up in Earth's atmosphere has ended in failure, the US space agency announced Wednesday. The rescue spacecraft, built by American startup Katalyst Space Technologies, could not be brought under control, leaving the Neil Gehrels Swift Observatory on course to re-enter the atmosphere and disintegrate later this year.

Launched in 2004, the Swift telescope was designed to detect and study gamma-ray bursts — brief but extraordinarily energetic explosions that rank among the most powerful events in the universe. Over two decades, it remained in heavy use by the global scientific community. But as the satellite gradually lost altitude, the risk grew that it would drift too close to Earth and burn up in the atmosphere. To prevent this, NASA commissioned Katalyst to attempt something that had never been done before: send an unmanned robotic spacecraft to intercept Swift, grab it with three movable arms, and boost it roughly 300 kilometres higher — back toward its original orbit — to extend its scientific life by years.

The rescue craft, named LINK, was launched on 3 July aboard a Pegasus rocket, itself released from an aircraft in flight. The plan required LINK to locate Swift in the vast expanse of space, fly around it, and execute a series of delicate docking and propulsion manoeuvres that had no precedent in spaceflight history. By 28 July, however, Katalyst reported that the spacecraft had been in an uncontrolled spin for 72 hours, suffering from multiple technical problems including a loss of communications. NASA and Katalyst formally called off the rescue attempt this week, citing "ongoing attitude control issues."

Despite the setback, NASA said LINK would still attempt to approach the Swift telescope in order to gather as much data as possible, with the aim of informing future satellite servicing missions. The agency had hoped the mission would serve as a proof of concept for giving ageing satellites a second life — a capability seen as increasingly important as the number of assets in orbit grows.

"This is not the outcome we were working toward, but it does not change why this mission was worth attempting," said NASA Administrator Jared Isaacman. "The team moved with extraordinary speed to give Swift a chance to carry out more science while advancing capabilities America will need for satellite servicing in the future." The original Swift telescope cost an estimated $250 million to develop and build, making the failed $30 million rescue attempt a costly but, NASA insists, instructive gamble.