NASA pauses most Swift science ops to buy time for reboost mission

Anticipated summer launch is cutting it fine

NASA has ended most science operations on its Swift observatory to keep the spacecraft in orbit a little longer.

The 21-year-old observatory's altitude has now dropped below 250 miles (400 kilometers) - it needs to sit above 185 miles (about 300 kilometers) to maximize the chances of an anticipated reboost mission.

"Normally, Swift quickly turns to view its targets – especially the fleeting, almost daily explosions called gamma-ray bursts – with multiple telescopes," said principal investigator S. Bradley Cenko at NASA's Goddard Space Flight Center. While the Burst Alert Telescope will continue to detect gamma-ray bursts, the spacecraft will no longer slew to observe targets with its other telescopes.

Stopping the slewing and leaving the spacecraft in an orientation to minimize atmospheric drag will reduce the rate at which Swift's orbit decays until a reboost mission is launched – currently anticipated for the summer.

NASA awarded Katalyst Space Technologies a contract in 2025 to raise the orbit of the spacecraft. At the time, the expectation was an orbit boost in spring 2026. In November 2025, Katalyst confirmed it would use an air-dropped Pegasus XL as the launch vehicle for a June 2026.

The Register contacted Katalyst for comment.

Swift is expected to re-enter Earth's atmosphere in 2026 unless reboosted. The spacecraft's science payload remains operational, but a reboost is required to keep the data flowing.

Swift's prime mission duration was two years and it had an expected orbital life of seven years. It has far exceeded both milestones and remains operational. However, it is now significantly below its original altitude [PDF] of 373 miles (600 km). This makes it an ideal candidate for a reboost, which, if it goes to plan, will demonstrate a useful capability and extend Swift's already impressive lifespan.

The spacecraft is showing its age. It fell into safe mode several times in recent years due to reaction wheel problems and gyroscope issues. The team was able to recover the spacecraft, and in 2022, discussed observations continuing into the 2030s. However, expansion of Earth's atmosphere during periods of increased solar activity has accelerated orbital decay, necessitating a reboost.

Cenko said: "We anticipate the reboost mission to launch in the summer, so we're transitioning operations now to give it the best margin we possibly can." ®