NASA ends Swift science mission and preserves major archive

NASA said on 23 October 2026 that the Neil Gehrels Swift Observatory had ended its science mission while orbiting less than 171 miles (275 kilometers) above Earth's surface. Atmospheric drag at this altitude prevented the satellite's telescopes from steadily observing astronomical targets.

Swift conducted its final observation on Oct. 20. NASA said the spacecraft was expected to re-enter the atmosphere in the next few weeks.

NASA said Swift observed more than 2,000 gamma-ray bursts and studied more than 1,400 supernova explosions. It also witnessed stars shredded by black holes, monitored active galaxies, conducted an all-sky X-ray survey, and studied asteroids and comets. Swift data contributed to about 7,000 published scientific papers.

NASA said Swift was designed for a two-year primary mission but remained productive for more than 10 times as long. It could detect and locate gamma-ray bursts, relay their positions to other observatories, and turn its telescopes to image the burst locations before their afterglows faded. This typically took Swift about a minute.

Swift achieved a milestone in May 2005 with GRB 050509B, which lasted just 0.03 seconds. It detected 11 X-ray photons, producing the first short burst with a detected afterglow. NASA said the observations supported the theory that short gamma-ray bursts likely came from mergers of two neutron stars.

NASA said the Swift archive contains nearly 22 years of brightness measurements, multiwavelength spectra, and more than 1.5 million images from its Ultraviolet/Optical Telescope. The public dataset spans approximately 12 terabytes. NASA said it would continue prioritizing options for rapid responses to cosmic events and use current missions to fill the gap in the meantime.