NASA’s Neil Gehrels Swift Observatory, facing the risk of an uncontrolled dive back to Earth, is set for a rescue ride on a Pegasus XL, the air-dropped rocket that hasn’t flown since 2021.
Flagstaff-based Katalyst has announced that the rocket to launch its LINK spacecraft on a rescue mission will be Northrop Grumman’s Pegasus XL air-launched vehicle. Assuming the mission launches in June 2026 as planned, it will be five years since the last flight of the Pegasus XL.
Time is running out for the venerable NASA observatory. In September, the agency reckoned there was a 50 percent chance of an uncontrolled reentry by mid-2026, increasing to 90 percent by the end of the year. Although the spacecraft was launched in 2004, it remains operational and could continue to capture data on gamma-ray bursts if boosted to a higher orbit.
NASA awarded Katalyst Space Technologies a $30 million contract to mount a rescue. The plan then was an orbit boost in spring 2026. Swift was never designed to be serviced in space, and the mission will be a first – the first time a commercial robotic spacecraft will capture an uncrewed government satellite.
While the choice of the Pegasus XL as a launch vehicle might raise an eyebrow or two, given the length of time since its last mission, there is logic in the selection. Swift’s orbit has a 20.6° inclination; it is tricky to reach from US launch sites, where most small rockets are limited to inclinations above around 27°.
Ghonhee Lee, CEO of Katalyst, said, “Pegasus is the kind of uniquely capable launcher we need for this mission.
“It’s the only launch vehicle that can meet the orbit, the schedule, and the cost to achieve something unprecedented with emerging technology.”
Those three factors are key. While something like a Falcon 9 could get Katalyst’s spacecraft to the desired orbit, it’s unlikely that it could do it for less than the price of a Pegasus XL dropped at 39,000 feet from the last flying Lockheed L-1011 Tristar (dubbed “Stargazer”).
Kurt Eberly, director of space launch for Northrop Grumman, said, “The versatility offered by Pegasus’ unique air-launch capability provides customers with a space launch solution that can be rapidly deployed anywhere on Earth to reach any orbit.
“The stringent mission requirements necessary to save the Swift observatory, including the unique low-inclination orbit and the tight mission timeline, all pointed to Pegasus being the perfect choice.”
Neither Katalyst nor Northrop Grumman has shared the launch cost, although it will have had to be priced keenly to fit within the $30 million budget allocated to the mission. ®