NASA launches rescue spacecraft to save aging Swift gamma-ray telescope from orbital decay
A three-armed robotic spacecraft named Link rocketed into orbit from the Pacific on Friday, beginning a months-long mission to grab the drifting Swift observatory and boost it to a safe altitude before it burns up in Earth's atmosphere.
Liftoff after delays
Weighing roughly half a ton, the Katalyst Space Technologies spacecraft was released from a Northrop Grumman Pegasus rocket carried aloft by a Lockheed TriStar jet over the Marshall Islands at 08:36 GMT on Friday. The launch had been postponed earlier in the week: an initial Tuesday attempt was scrubbed due to weather, and a Thursday try was aborted by a last-minute software problem on the launcher.
The Pegasus, known for air-launching from the belly of a plane, sent Link toward low-Earth orbit, where it will embark on a month-long trek to the vicinity of the crippled observatory.
The broken telescope
Swift has been aloft since 2004 and revolutionized the study of gamma-ray bursts, the most powerful explosions in the universe. But the observatory has no onboard propulsion. Intensified solar storms have accelerated its orbital decay; without intervention, NASA said, it faced a 90% chance of reentering and burning up by October. The telescope is valued at $250 million to $500 million, depending on the source.
This is a high-risk, high-reward mission. The biggest danger was always we don't launch anything and we let Swift burn up in the atmosphere.
The approach and capture
Link will first deploy its solar panels and run system checks once it reaches a parking orbit. Then, using five sensor systems and three sets of thrusters, the autonomous vehicle will close to within about six miles of Swift, initiating a final rendezvous that should take another week.
The spacecraft is equipped with three robot arms, each fitted with hand-like grippers, designed to latch onto a satellite never meant to be docked with. Katalyst built the entire vehicle on a nine-month production schedule under a $30 million NASA contract.
- Original launch date scrubbed due to poor weather over the Pacific.
- Thursday launch attempt aborted by a last-minute software issue on the Pegasus rocket.
- Launch from Kwajalein Atoll at 08:36 GMT. Link begins month-long voyage to Swift.
- Expected arrival in the vicinity of Swift; autonomous approach and capture within about a week.
- After a roughly 60-day tow, Swift reaches its target altitude of about 600 km and may resume science operations.
The climb back
If capture succeeds, Link will fire its thrusters to slowly raise Swift by about 150 to 300 kilometers, aiming to double its altitude and place it in a sustainable 600-kilometer orbit. The tow is expected to last at least 60 days.
I'm just deeply thankful that we're even giving this a go.
NASA paused Swift's science operations earlier this year to conserve its dwindling orbit. Mission planners hope the telescope can resume scanning the sky for transient events as early as September and continue working for another five years or more.
