Two of the three science instruments aboard Swift resumed operation on Aug. 26. The spacecraft they ride on is still sinking toward Earth.
That is the blunt state of play for NASA’s Neil Gehrels Swift Observatory. The Ultraviolet/Optical Telescope and the X-ray Telescope are gathering data once more, having been powered down since February. What isn’t happening is the rescue mission meant to hand them several more years of life.
What came back, and what didn’t
February’s shutdown of both instruments was a drag-reduction measure, intended to stretch whatever orbital time Swift had left while NASA pursued a possible boost. Power was restored to them on Wednesday, Aug. 26.
Instrument number three, the Burst Alert Telescope, remains offline. Its use was halted in April to reduce how much power the spacecraft consumed, freeing engineers to tilt Swift’s solar panels into an orientation that produced less drag. Restoring it to data collection is expected within the next few weeks.
For now, then, Swift amounts to about two-thirds of an observatory — and the absent third is the piece that detects the bursts.
The rescue that fell apart
In September 2025, NASA put Katalyst Space under contract for something never before attempted with a science telescope: send up a second spacecraft, take hold of Swift, and tow it to a higher orbit.
The company was given a single year to design, build, test and launch that vehicle — named LINK — then fly it out to Swift and finish the boost. One year. For a mission built around rendezvous and capture.
July saw LINK lift off atop a Northrop Grumman Pegasus rocket. Trouble controlling its orientation surfaced later that same month, a particularly unwelcome failure on a craft whose whole purpose is precise maneuvering at close quarters.
The announcement came on Aug. 19: NASA and Katalyst confirmed LINK would not try to capture Swift and lift its orbit.
That doesn’t end the flight. Katalyst intends to bring LINK into Swift’s vicinity anyway for rendezvous and proximity operations — a demonstration of technologies applicable to in-space satellite servicing, including future missions in which one spacecraft closes on another and works alongside it. Valuable data, certainly. Just not a rescued telescope.
Why the Sun is to blame
Lacking any propulsion capable of raising its own orbit, Swift has no way to push back against drag. Even at altitudes of hundreds of miles, enough residual atmosphere lingers to slow a spacecraft and gradually drag its orbit downward.
Solar activity in recent months has compounded the problem. When the Sun grows more active, it pumps additional energy into Earth’s upper atmosphere, which swells and drives its outer layers deeper into space. Anything in low Earth orbit encounters more drag as a result.
In Swift’s case, the consequence has been altitude loss running ahead of projections.
The number that matters is 185
By NASA’s estimate, the low-drag operating configuration would keep the observatory above 185 miles (300 kilometers) through October.
Beneath 185 miles (300 kilometers), running the telescope becomes more difficult, and altitude is expected to bleed away faster as drag builds. Think of it as a threshold rather than a cliff — but it marks the end of routine operations.
Now that science observations have resumed, the team anticipates Swift reaching that mark within the next one to two months.
Twenty-one years of catching things that don’t wait
Across 21 years of operation, observing at multiple wavelengths of light, Swift’s defining strength has been quickness. Detect an outburst, slew to the source, and alert observatories on the ground and in orbit — all fast enough that others can catch the event before it fades.
That is the capability now on a countdown. For anyone tracking transient astronomy, the practical upshot is this: Swift’s follow-up alerts are a resource with a known expiration window, and how much of that window proves usable hinges on the Burst Alert Telescope coming back in the weeks ahead.
Until that point, Swift keeps watching — and keeps falling.