NASA ends Swift telescope mission after 22 years

NASA's Swift observatory has finished watching the sky. It made its last science observation on Tuesday, 20 October, and NASA announced the mission's end Friday. Launched in 2004 for a planned two-year primary mission, it kept working for nearly 22 years. NASA says it observed more than 2,000 gamma-ray bursts, among the universe's most powerful explosions.

Swift was unusually quick. When it detected a burst, it could turn its telescopes toward the fading afterglow and alert other observatories. That helped astronomers study events that might otherwise disappear before anyone looked. Its archive remains available even though the spacecraft has stopped working.

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Atmospheric drag has pulled Swift too low for steady observations. NASA expects it to re-enter the atmosphere in the coming weeks. The agency is considering how other telescopes can fill its rapid-response role.