TL;DR: NASA's Neil Gehrels Swift Observatory will fall back to Earth in an uncontrolled reentry after a privately built rescue spacecraft failed to boost it to a higher orbit.
NASA confirmed the rescue attempt is over, and agency officials said Swift is not expected to reenter sooner than October, according to Space.com's Aug. 27 report.
Rescue mission ends
The observatory launched to Earth orbit in November 2004 and spent more than two decades studying gamma-ray bursts and other cosmic objects with three telescopes, according to Space.com.
Its orbit decayed quickly because of high solar activity and atmospheric drag, prompting NASA to seek outside help in September 2025, according to Space.com.
NASA selected Arizona-based Katalyst Space Technologies under a $30 million contract to perform the reboost, according to Space.com.
Katalyst designed, built and launched a robotic spacecraft called LINK within nine months, according to Space.com.
LINK launched on July 3 to meet Swift and haul it to a higher orbit, according to Space.com.
The plan called for LINK to rendezvous with, grapple and slowly raise Swift's altitude over several months, according to NASA's Swift: News page.
LINK was built as a refrigerator-size spacecraft, according to Science News.
The mission lifted off from Kwajalein Atoll in the Marshall Islands aboard a Northrop Grumman Pegasus XL rocket, according to NASA's Swift: News page.
An airplane carrying the rocket and LINK departed NASA's Wallops Flight Facility in Virginia on June 18, according to NASA's Swift: News page.
Engineers had completed installation of LINK into the Pegasus XL on June 9 at Wallops, according to NASA's Swift: News page.
LINK arrived at Wallops on June 5 for final preparations, according to NASA's Swift: News page.
What went wrong with LINK
LINK suffered attitude-control issues after launch, leading NASA and Katalyst to wave off the rescue attempt, according to Space.com.
The trouble began just weeks after launch when its maneuvering gear malfunctioned, according to Science News.
Over one weekend, LINK experienced attitude-control problems that caused it to spin and produced sporadic communications, according to NASA's Swift: News page.
A preliminary investigation found two of LINK's three reaction wheels were not operable, according to NASA's Swift: News page.
The investigation also found some loss of functionality in its cold gas thruster system, according to NASA's Swift: News page.
During the following week, teams successfully reduced the spin of LINK, according to NASA's Swift: News page.
Katalyst later uploaded a flight software update with new attitude-control algorithms designed to maintain stability using remaining actuators, according to NASA's Swift: News page.
The Katalyst team managed to stabilize the rotating spacecraft with help from its main propulsion engines, according to Science News.
That recovery effort eventually left both systems with insufficient fuel to save Swift, according to Science News.
NASA and Katalyst called off the rescue attempt on Aug. 19, according to Science News.
NASA announced that day that LINK will not capture or boost an agency satellite to a higher altitude as planned because of the ongoing attitude-control issue, according to NASA's Swift: News page.
There is no backup mission to save Swift, according to Science News.
Katalyst Chief Executive Ghonhee Lee discussed the outcome on CNN News Central on Aug. 24, according to Space.com.
"This was an ambitious, high-risk, high-reward mission where we designed, built and launched a space robot within nine months," Lee said, according to Space.com.
Lee said the timeline worked against the group, according to Space.com.
"I think if we had had 12 months even — just three more months — it would have made a tremendous difference," Lee told CNN's Kate Bolduan, according to Space.com.
When and where Swift could fall
"Yes, Swift will have an uncontrolled reentry," Alise Fisher, public affairs specialist in astrophysics in NASA's Office of Communications, said, according to Space.com.
Fisher said the specific timing will depend on a number of factors, according to Space.com.
"Swift is not likely to reenter sooner than October. NASA will share more information as reentry approaches, following established interagency procedures for such notifications," Fisher said, according to Space.com.
The observatory was operating roughly 340 kilometers above Earth while losing altitude, according to Science News.
Swift dropped about 10 kilometers in the last month, Brad Cenko, NASA astrophysicist and principal investigator on the Swift mission, said in an email, according to Science News.
The point of no return — when managers can no longer control the observatory's movements — is somewhere below about 300 kilometers in altitude, according to Science News.
The latest modeling suggests Swift will plunge into the atmosphere in late November or December, Cenko said, according to Science News.
If scientists resume science operations, reentry would happen even sooner because observing maneuvers increase drag, according to Science News.
Ahead of LINK's arrival, NASA had suspended Swift's scientific maneuvering and powered off instrument detectors to reduce drag and prolong orbital lifetime, Cenko said, according to Science News.
Swift has an orbital inclination of 21 degrees, so it could reenter anywhere between 21 degrees North and 21 degrees South latitude, according to Space.com.
"The most likely outcome is that any surviving debris will land in the sea, but there is a chance it could impact a built-up area and cause a casualty," Ewan Wright, a doctoral student in interdisciplinary studies at the University of British Columbia and junior fellow at the university's Outer Space Institute, said, according to Space.com.
Wright said uncontrolled reentries of satellites and rockets are increasing each year and the chance that someone will be hit is growing, according to Space.com.
What could survive the fall
NASA expects most of Swift to burn up during passage through the atmosphere, Fisher said, according to Space.com.
"But some components are expected to survive reentry. The risk of harm coming to anyone on Earth is unlikely," Fisher said, according to Space.com.
Swift's dry mass is 613 kilograms, or 1,351 pounds, according to Space.com.
Its science gear includes a Burst Alert Telescope, an Ultraviolet/Optical Telescope and an X-Ray Telescope, according to Space.com.
"The dry mass and instruments are such that it will likely disintegrate sufficiently upon reentry to not pose a ground casualty hazard," Darren McKnight, senior technical fellow at LeoLabs, said, according to Space.com.
McKnight said the internal workings of the X-ray and optical telescopes might survive, according to Space.com.
He identified optical lenses and titanium tanks as components that might reach the ground, according to Space.com.
McKnight said he was sure an analysis had been done but had seen no public reporting on a survivability analysis, according to Space.com.
Wright said Swift is unlikely to burn up entirely because of its mass, according to Space.com.
Why scientists valued Swift
Swift observes gamma-ray bursts, flashes of radiation from outside the Milky Way that last seconds, according to Science News.
Unlike other space telescopes, Swift is agile, and it can swivel toward the afterglow within minutes to pinpoint the source, according to Science News.
Researchers think longer bursts are caused by the deaths of very massive stars, Huei Sears, an astrophysicist at Rutgers University in New Brunswick, New Jersey, said, according to Science News.
"Our home galaxy is just too metal-rich to host long gamma-ray bursts," Sears said, according to Science News.
These events let scientists briefly observe another galaxy and glimpse its stellar environment, Sears said, according to Science News.
"It’s always sad to lose something as beautiful and fantastic as a cathedral in space," Sears said, according to Science News.
A test for satellite servicing
The Katalyst mission was the latest demonstration of on-orbit satellite servicing, with robots acting like orbital mechanics, according to Science News.
NASA gave the company nine months to develop LINK, and engineers rushed testing because time was short, according to Science News.
Katalyst also sought to mount a similar mission to the 36-year-old Hubble Space Telescope, and Swift was meant as a preview, according to Science News.
Before his appointment as NASA administrator, Jared Isaacman had offered to mount a SpaceX mission to raise Hubble's orbit, according to Science News.
"The technology to enable servicing is on a very good path," David Barnhart, an astronautical engineer at the University of Southern California in Los Angeles, said, according to Science News.
Barnhart cited advances in rendezvous sensors, propulsion systems and robotic arms, according to Science News.
In July, the U.S. government dispatched a spacecraft that will eventually inspect, relocate and attach life-extending jetpacks to existing satellites, according to Science News.
Future probes could refuel spacecraft, drag defunct satellites toward reentry or haul historic objects into long-lasting orbits, according to Science News.
Barnhart is particularly interested in salvaging parts, such as removing solar panels from a dead satellite for use on a new one, according to Science News.
"There's full expectations that the first missions may not succeed," Barnhart said, according to Science News.
What happens to LINK
There is no rescue mission for the rescue mission, according to Science News.
Katalyst plans to conduct rendezvous and proximity operations, shortening the distance between LINK and Swift to single kilometers in coming weeks, marketing director Esther Jeohn said, according to Science News.
The company did not respond to a question about LINK's eventual fate, according to Science News.
Cenko said the spacecraft is required to reenter Earth's atmosphere within five years, according to Science News.