NASA's Swift Observatory Ends Its Nearly 22-Year Science Mission

NASA has ended science operations of the Neil Gehrels Swift Observatory after its orbit decayed to below 171 miles (275 km) above Earth's surface — too low for its telescopes to maintain stable pointing at astronomical targets. Swift conducted its final observation on October 20, with atmospheric re-entry expected within weeks. Launched on November 20, 2004, the spacecraft was originally designed for a two-year primary mission but remained productive for more than 10 times that span. Over its lifetime, Swift observed more than 2,000 gamma-ray bursts and more than 1,400 supernova explosions, witnessed stars torn apart by black holes, monitored active galaxies, and contributed to roughly 7,000 published scientific papers. The observatory could schedule up to 75 independent targets per day and could respond to ground-commanded target-of-opportunity requests in as little as a few minutes. Its archive holds nearly 22 years of brightness measurements, more than 1.5 million images from its Ultraviolet/Optical Telescope, and approximately 12 terabytes of data in total — the storage equivalent of around 600 high-definition movies. NASA says it will explore ways to preserve rapid-response capability for cosmic events using existing and future missions, while Swift's archive is expected to support new discoveries for decades to come.