Atmospheric Drag Ends a 22-Year Mission
NASA officially ended science operations for the space telescope after its orbit dropped below 171 miles, preventing the instruments from holding steady on astronomical targets.
Launched on Nov. 20, 2004, the observatory was originally built for a two-year primary mission to study gamma-ray bursts. Instead, it operated for more than a decade past its intended lifespan, capturing more than 2,000 gamma-ray bursts, 1,400 supernovae, and stars being ripped apart by black holes.
Solar Activity Accelerates Orbital Decay
Intense solar activity in recent years increased atmospheric drag on satellites in Earth orbit, causing the telescope to steadily lose altitude. While the craft was originally placed in an orbit ranging from 585 to 604 kilometers, Earth’s tenuous outer atmosphere eventually slowed it down enough to make continued scientific observations impossible, according to mission updates.
NASA attempted a rescue mission in July to lift the satellite using a private spacecraft launched in early July. However, technical issues and hardware malfunctions prevented a boost attempt, and the rescue craft burned up in the atmosphere in late August.
FINAL ORBIT 🛰️: The NASA telescope that detected thousands of gamma-ray bursts has reached its final days. The agency has ended its effort to save the Neil Gehrels Swift Observatory after NASA failed to adjust the telescope’s altitude above Earth. Swift conducted its final… pic.twitter.com/tR6KrF9535
Heavy Components May Survive Uncontrolled Atmospheric Reentry
Because the telescope lacks onboard rockets, its final plunge will be completely uncontrolled. Dean Sladen, Quality Manager & Aerospace Engineer at Accu Components, explained in an email to IFLScience that once the satellite falls, extreme friction heats the surrounding air until the craft glows. Solar panels and antennas will tear off first, and the main body will break apart at roughly 78 kilometers.
Most of the structure will melt and vaporize during the descent, but certain heavy components are expected to survive the heat. NASA expects the spacecraft to re-enter the atmosphere in the next few weeks.
Swift Leaves Archive of 12 Terabytes for Astrophysics
During its career, Swift contributed data to roughly 7,000 scientific papers and generated a public archive spanning approximately 12 terabytes of multiwavelength observations. Shawn Domagal-Goldman, director of the Astrophysics Division at NASA Headquarters, noted in a statement that the mission leaves behind an extraordinary archive to fuel new discoveries. Domagal-Goldman added that Swift’s fast-acting observations played a major role in advancing our understanding of the changing universe and was part of a revolution in astrophysics.
The mission was led by its first principal investigator, Neil Gehrels, whom NASA honored by renaming the spacecraft in 2018. Cenko also explained that this process typically took about a minute. Astrophysicist Lynn Cominsky of Sonoma State University in Rohnert Park, Calif., noted that Almost immediately after launch, Swift started discovering things.
As Swift’s tenure unfolded, the spacecraft was utilized for various other cosmic phenomena; as astrophysicist Phil Evans of the University of Leicester in England put it, With scientists, if you give them a tool to do something, they will other find other things that you can do with that tool.
With Swift gone, high-energy astronomy loses a nimble asset capable of swinging its co-aligned optical, ultraviolet, and X-ray telescopes toward fleeting cosmic explosions within a minute. NASA is exploring ways to use its existing fleet and fast-to-orbit commercial capabilities to fill the operational gap left by the retired observatory.
Frequently Asked Questions About the Swift Reentry
When did Swift make its final observation?
The telescope conducted its final scientific observation on Oct. 20, before NASA officially shut down operations due to the satellite’s low orbital altitude.
What parts of the telescope are expected to survive reentry?
According to aerospace engineer Dean Sladen, only a handful of small, scorched fragments are expected to make it down, nothing recognisable as a telescope.
Why couldn’t NASA save the spacecraft?
NASA arranged a rescue attempt with a private spacecraft that launched in early July, but hardware malfunctions prevented the boost attempt before the rescue craft burned up in August.