NASA’s Neil Gehrels Swift Observatory is expected to re-enter Earth’s atmosphere around November 4, according to an estimate from the U.S. Space Force. Most of the telescope is expected to burn up during its descent, though some components could survive and fall into the ocean or elsewhere within the projected re-entry zone.
Swift’s orbit began to decay faster than expected following unusually strong solar activity in late 2024, which increased atmospheric drag. NASA contracted Arizona-based Katalyst Space Technologies to build a spacecraft designed to lift the observatory into a higher orbit. The rescue craft launched on July 3, but the first-of-its-kind mission failed after problems including an issue with its orientation control system. NASA shut Swift down in late October because it had become too unsteady.
Launched in November 2004 for a planned two-year mission to study gamma-ray bursts, Swift spent 22 years observing the universe. It detected more than 2,000 gamma-ray bursts and 1,400 supernova explosions, as well as stars being torn apart by black holes, asteroids, comets and other phenomena. Its observations contributed to roughly 7,000 scientific papers.
The observatory also acted as a first responder: it sent alerts about noteworthy events so other telescopes, including Hubble and the James Webb Space Telescope, could investigate them further. Among Swift’s notable contributions in 2017 were detecting signs of a neutron-star merger and helping trace a high-energy neutrino to its source.
The telescope’s re-entry could give researchers information about how spacecraft break apart in the atmosphere, potentially informing the design of safer satellites. Researchers are also interested in the effects of material from re-entering spacecraft on the upper atmosphere.
Although Swift’s observing mission has ended, its archived data remains available for researchers to study and could support future discoveries.
Sources: Smithsonian Magazine.