NASA's Swift Observatory Is Coming Down: What to Know About Its Re-Entry

As of November 3, 2026: NASA's Neil Gehrels Swift Observatory is expected to re-enter Earth's atmosphere on Wednesday, November 4. It made its final observation on October 20. NASA expects most of the roughly 3,200-pound (about 1,450 kg) spacecraft to burn up, but some components are expected to survive re-entry. NASA says the risk of harm coming to anyone on Earth "is unlikely," approximately 1 in 2,100.

When and where

NASA's November 2 update said that, as of Monday, the U.S. Space Force predicted re-entry "at approximately 3:30 a.m. EST, Nov. 4, with an uncertainty of 11 hours." That is 08:30 UTC.

U.S. re-entry predictions are published as Tracking and Impact Prediction (TIP) messages on Space-Track.org, U.S. Space Command's public website for space surveillance data. The newest for Swift (catalogue number 28485) at the time of writing, issued at 11:32 UTC on November 3, predicts re-entry at 10:47 UTC on November 4 (5:47 a.m. EST). As of this writing, NASA has not given an uncertainty for that newer prediction. By the window field in the messages, its window is less than half the size of the one in the November 2 message, whose time matches NASA's figure.

NASA says re-entry locations "can vary from hemisphere to hemisphere and depend on when it re-enters," but because of Swift's low inclination, surviving fragments are limited to between 20.6 degrees south and 20.6 degrees north latitude. One detail is easy to misread: the latitude and longitude in a TIP message mark where the object is predicted to reach 10 km altitude, Space-Track says, "not the predicted Earth impact location."

What Swift did

Swift launched on November 20, 2004, to study gamma-ray bursts, outbursts that came and went too quickly for large telescopes to be pointed at them. It had to detect a burst, send its position to other observatories and swing its own X-ray and ultraviolet/optical telescopes onto the spot before the afterglow faded. "This typically took Swift about a minute to do," said S. Bradley Cenko, the mission's principal investigator at NASA's Goddard Space Flight Center.

That speed paid off in May 2005 with GRB 050509B, a 0.03-second burst that became the first short gamma-ray burst with a detected afterglow; NASA says those observations showed short bursts likely come from mergers of two neutron stars. In all, Swift observed more than 2,000 gamma-ray bursts and more than 1,400 supernova explosions, and its data contributed to about 7,000 published papers. Designed for a two-year primary mission, it was "productive for more than 10 times as long," said Shawn Domagal-Goldman, director of NASA's Astrophysics Division. NASA renamed the mission in 2018 to honor its first principal investigator, Neil Gehrels, after his death.

Why it is coming down

All satellites in low Earth orbit experience atmospheric drag, and Swift has no propulsion system to counteract it. NASA says recent solar activity magnified the drag on Swift, which began to sink faster than anticipated. "Without intervention, Swift was going to re-enter the atmosphere by year's end," Domagal-Goldman said in September.

In September 2025 NASA contracted Katalyst Space of Flagstaff, Arizona, to build and launch a spacecraft, LINK, that would meet, grab and lift Swift. To buy time, controllers at Penn State, home of Swift's Mission Operations Center, began pointing Swift at low-drag spots on the sky in place of some science targets in December 2025, switched over entirely by February 2026, and turned its instruments off by April.

LINK launched in July 2026 on a Northrop Grumman Pegasus XL rocket from Kwajalein Atoll, then developed problems controlling its orientation. On August 19, NASA and Katalyst announced that LINK would not capture or boost Swift. LINK attempted technology demonstrations instead and re-entered on September 25.

Swift turned its telescopes back on from August 26 and observed hundreds of science targets. The return to observations increased drag, NASA says, and Swift again began to sink rapidly. On October 20 it reached 171 miles (275 km), could no longer compensate for the drag and entered safe mode; the Penn State team then sent a command that effectively ended Swift operations.

Why the prediction window narrows

ESA's Space Debris Office, in the user guide for its re-entry predictions, attributes the errors, in "an overly general approximation," 70% to the atmosphere, 20% to the object's ballistic coefficient and 10% to orbit determination, and says that, in general, it applies an uncertainty margin of plus or minus 20% of the remaining orbital lifetime to its own predictions. Under a margin like that, the window shrinks as the time left shrinks, and the guide says re-entries "cannot be predicted with a high degree of confidence until the last few passes prior to re-entry."

The four Swift TIPs issued from October 31 to November 3 all point to November 4, at 09:25, 00:30, 08:30 and then 10:47 UTC, and the window in each message has been smaller than the one before. The newest window is less than a third the size of the first. In its API guidance, Space-Track lets data users check for new messages every 10 minutes once an object is within 12 hours of re-entry, "until the final TIP arrives."

Where to follow it

• NASA's Swift blog (science.nasa.gov/blogs/swift): NASA says to monitor it "for continued updates."
• Space-Track.org (space-track.org): the TIP messages themselves. Space-Track lists satellite decay and reentry predictions among its basic services and requires a user account to read them.
• On SpaceNexus: our space debris guide and space weather guide, on drag.

Sources

All accessed November 3, 2026. Re-entry predictions: USSPACECOM data via Space-Track.org.

• NASA Swift blog: "NASA's Swift Observatory to Re-Enter Atmosphere" (Alise Fisher, November 2, 2026)
• NASA Swift blog: "NASA's Swift Mission Ends Ahead of Re-Entry" (Jeanette Kazmierczak, October 23, 2026)
• NASA: "NASA's Swift Mission Ends, Leaves Behind Scientific Bonanza" (Francis Reddy, October 23, 2026)
• NASA: "NASA Highlights Lessons Learned From Swift Boost Mission" (Jeanette Kazmierczak, September 28, 2026)
• NASA Swift blog: "NASA's Swift Powers On Third Instrument, Restarts Automated Slewing" (September 25, 2026)
• NASA Swift blog: "NASA's Swift Restarts Science Observations" (August 28, 2026)
• NASA Swift blog: "NASA Updates Next Steps for Commercial Swift Boost Mission" (August 19, 2026)
• NASA mission pages: Neil Gehrels Swift Observatory and Swift Boost Mission
• Space-Track.org: Tracking and Impact Prediction messages for Swift (NORAD 28485), issued October 31 to November 3, 2026, and the site's documentation (glossary and API guidelines)
• ESA Space Debris Office: Re-entry Prediction Front-end User Guide (GEN-REN-MAN-00232-OPS-GR, 2018)