NASA Ends Swift Observatory Mission After 22 Years as Orbit Decays
By Francis Reddy · · TexaHub · Space
NASA ended the science mission of its Neil Gehrels Swift Observatory after the spacecraft sank to 275 kilometres on Oct. 20. Swift, launched in 2004, is expected to re-enter the atmosphere within a few weeks.
Final Observation on Oct. 20
NASA announced on Oct. 23 that its Neil Gehrels Swift Observatory had ended its science mission. The spacecraft made its final observation on Oct. 20 and is expected to re-enter the atmosphere within a few weeks. [1]
On Oct. 20 Swift reached an altitude of 171 miles (275 kilometres), where it could no longer compensate for increased atmospheric drag, and it entered safe mode. The operations team at Penn State in University Park then sent a command that effectively ended Swift operations to prepare the spacecraft for re-entry. [2]
Failed Boost Attempt
Recent solar activity increased drag on Swift and caused it to sink rapidly. A high-risk, fast-turnaround servicing mission intended to raise its orbit ended in August without attempting the boost. [2]
The team had paused science observations to reduce drag, then restarted them in August. Swift went on to observe hundreds of targets, including remnants of stellar explosions, active supermassive black holes and comets, but resuming observations increased drag again and the spacecraft resumed its rapid descent. [2]
Mission Record
Swift launched on Nov. 20, 2004, for a two-year primary mission and operated more than ten times that long. NASA renamed it in 2018 after its first principal investigator, Neil Gehrels. [1]
The observatory recorded more than 2,000 gamma-ray bursts and studied more than 1,400 supernovae, and its data has supported about 7,000 published papers. In May 2005 it detected the afterglow of GRB 050509B, the first short gamma-ray burst with a detected afterglow, a 0.03-second event from which Swift collected 11 X-ray photons. [1]
Swift's flexible scheduling allowed it to respond to target-of-opportunity requests within minutes and to observe up to 75 independent targets per day. [1]
Its archive holds nearly 22 years of brightness measurements, more than 1.5 million images from the Ultraviolet/Optical Telescope and about 12 terabytes of public data. Shawn Domagal-Goldman, director of NASA's Astrophysics Division, said Swift "delivered an incredible, lasting return on investment for the nation". NASA said it would use current missions to fill the gap in rapid response to cosmic events. [1]
Sources
[1] NASA's Swift Mission Ends, Leaves Behind Scientific Bonanza — NASA Science
[2] NASA's Swift Mission Ends Ahead of Re-Entry — NASA Science