NASA ended the science mission of the Neil Gehrels Swift Observatory after the satellite dropped below 275 kilometers, where air drag stops its telescopes from holding steady. Swift made its final observation on October 20 and is expected to burn up in Earth’s atmosphere within weeks.
Swift Made Final Observation on October 20
The spacecraft entered safe mode on October 20 when it could no longer compensate for the extra drag generated by a puffed-up upper atmosphere caused by strong solar activity. Operations team members at Pennsylvania State University then sent the command to end science work. NASA announced the decision on October 23 and has not set a specific date for re-entry.
Spacecraft Tracked More Than 2,000 Gamma-Ray Bursts
Built for a two-year primary mission, the observatory worked for nearly 22 years after launching on November 20, 2004. During its operational lifetime, it recorded more than 2,000 gamma-ray bursts and more than 1,400 supernovae. Data collected by the satellite fed about 7,000 scientific papers, while its public archive containing roughly 12 terabytes of data remains open.
Operations Team Responded to Rapid Outbursts
Gamma-ray bursts last anywhere from a fraction of a second to a few minutes and usually faded before large telescopes could locate them prior to Swift’s launch. The satellite combined a gamma-ray detector with co-aligned X-ray and optical-ultraviolet telescopes, allowing it to schedule up to 75 independent targets a day and react to urgent requests from other research teams.
Science operations for our Neil Gehrels Swift Observatory have now ended.With the spacecraft orbiting less than 171 miles (275 kilometers) above Earth, atmospheric drag prevents the satellite’s telescopes from steadily gazing at their cosmic targets. 🧵 pic.twitter.com/nl4dHq1rmp
Swift was designed as a satellite dedicated to studying gamma-ray bursts, outbursts that came and went so quickly that no one could target them with large telescopes to learn more,
said S. Bradley Cenko, the mission’s principal investigator at NASA’s Goddard Space Flight Center.
Rescue Attempt Fell Short in August
NASA hired Katalyst Space Technologies to grab Swift with a robotic spacecraft and lift it to a higher orbit, but the rescue was called off in August after the LINK vehicle ran into control problems. Because the observatory carried no propulsion system, the cancelled boost mission left the satellite with no backup plan as solar activity sped up its orbital decay.
This is not the outcome we were working toward, but it does not change why this mission was worth attempting,
said NASA Administrator Jared Isaacman.
Frequently Asked Questions About the Mission
What was Swift’s final discovery before entering safe mode?
Swift made its final observation on October 20 before entering safe mode when it could no longer fight atmospheric drag at altitudes below 275 kilometers.
How much data did Swift archive over its lifetime?
The mission compiled a public archive of roughly 12 terabytes, which is roughly equivalent to the storage capacity of 600 high-definition movies.
Why couldn’t NASA save the observatory with a robotic rescue?
NASA hired Katalyst Space Technologies to lift Swift to a higher orbit, but the rescue was cancelled in August after the LINK vehicle experienced control problems.
NASA's Neil Gehrels Swift Observatory has ended its mission following a failed reboost attempt and is expected to reenter Earth's atmosphere in November.via @SpaceNews_Inc pic.twitter.com/w30dLeyzQj
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