Key Takeaways
- The Swift Boost rescue mission is set to launch today, Thursday 2 July, at 10:09am UK time (09:09 GMT) after two weather delays
- It's the final flight of Northrop Grumman's Pegasus XL — the rocket that launches from underneath a converted airliner at 39,000 feet
- On board is LINK, a fridge-sized robot built by Katalyst Space Technologies that will grab NASA's falling Swift telescope with three arms and push it back up to a safe orbit
- LINK will be the first private spacecraft ever to capture a US government satellite in orbit
- The whole rescue — launch included — is costing NASA about $30 million, and the capture itself follows in the weeks after launch
📑 Table of Contents
Swift Rescue Launch Time: When and How to Follow It From the UK
Third time lucky, hopefully. After two days of weather delays, the mission to save NASA's falling Swift telescope is set to launch today, Thursday 2 July, at 10:09am UK time (09:09 GMT).
If that seems an odd hour for a rocket launch, it's because this one happens on the other side of the planet. The rocket takes off from Bucholz Army Airfield on Kwajalein Atoll in the Marshall Islands, out in the middle of the Pacific, where it will be 9:09 in the evening. Well, "takes off" isn't quite right either. It gets carried up by an aeroplane and dropped. More on that in a moment.
There's no launchpad livestream for this one, since the whole thing happens from an aircraft over the open ocean. The best way to follow it is NASA's Swift blog, which posts updates through the attempt, along with Katalyst Space and Northrop Grumman on social media. Confirmation of a good launch usually lands within the hour.
We covered the full story of the rescue last month. Here's what today is about, and why it's worth your attention.
Why NASA's Swift Telescope Needs Rescuing
The short version: the Neil Gehrels Swift Observatory, NASA's 22-year-old gamma-ray burst hunter, is falling out of the sky through no fault of its own.
A stormier-than-expected solar maximum has heated and puffed up Earth's upper atmosphere, and that extra wisp of air acts as a brake on anything orbiting through it. Swift has sunk from its original 600km orbit to around 400km, and the lower it gets, the faster it falls. Left alone, it would most likely burn up before the end of 2026. The telescope still works beautifully. It simply has no engine, so it can't climb back up on its own.
So NASA hired someone to give it a push. That someone is Katalyst Space Technologies, an Arizona startup that built a rescue robot in under a year for about $30 million. Today, that robot goes to space.
Pegasus XL's Final Flight: A Rocket Dropped From a Plane
Today is also a farewell. The rocket carrying the rescue robot is a Pegasus XL, and this is the last one that will ever fly.
Pegasus doesn't use a launchpad. It rides bolted under the belly of Stargazer, a converted L-1011 airliner, which climbs to 39,000 feet and lets go. The rocket free-falls for five seconds, lights its motor in mid-air, and climbs to orbit from there. It's been doing this since 1990, when it became one of the first privately developed rockets to reach space, and it has launched dozens of missions since. Cheaper rockets have made air-launch a niche business, though, and the fleet is retiring.
There's a nice symmetry in the send-off. Pegasus launched Swift itself back in November 2004. Now, 22 years later, the same type of rocket is flying its final mission to save the telescope it once carried. Old rocket, old telescope, one last job.
The LINK Spacecraft: How the Capture Will Work
Tucked inside the Pegasus fairing is LINK, a robot about the size of a fridge, weighing roughly 400kg, with three robotic arms and a set of gentle electric thrusters.
Its job sounds simple and is anything but. Swift was launched long before anyone planned to service satellites in orbit, so it has no docking ring, no grapple points, nothing designed to be grabbed. LINK has to close in on a spacecraft the size of a small van, choose a safe place to take hold, and grip on with its arms. The one mercy is that Swift is alive and can hold itself steady. Engineers describe it as an "unprepared but cooperative" partner: it can't help with the rescue, but it won't fight it.
If the grab works, LINK becomes the first private spacecraft ever to capture a US government satellite in orbit. Nobody has done this before. That's worth sitting with for a second — the entire history of spaceflight, and this exact manoeuvre has never once been pulled off.
Watch the same sky Swift lives in
You can't see the rescue from the ground, but the low orbit where it happens is full of satellites you can watch cross the sky on any clear night. A decent pair of binoculars makes satellite-spotting genuinely addictive.
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What Happens After Launch: The Rescue Timeline
A clean launch today is only the opening move. Here's roughly how the rest plays out.
First, LINK separates from the Pegasus and checks itself out in orbit. Then comes the chase: over days to weeks, it fine-tunes its orbit to creep up on Swift, hundreds of kilometres up. The capture attempt follows, slow and careful, with the three arms taking hold of a telescope that was never built to be held.
Then the long push. LINK's electric thrusters are gentle by design, so raising Swift's orbit takes about six weeks of steady nudging. The goal is to walk the telescope back up towards the 600km it started from, where the air is thin enough to leave it alone for years. If all goes well, Swift should be safely parked by the end of the summer, free to get back to its day job of catching the biggest explosions in the universe.
We'll cover the capture attempt when it comes. Today's job is simpler: get off the plane, light the motor, reach orbit.
Why the Swift Rescue Mission Matters
It would be easy to file this under "nice story about an old telescope", but the stakes are bigger than Swift.
Right now, when a satellite runs out of altitude or luck, that's the end. It becomes junk, and low Earth orbit already has far too much of that. A proven, cheap way to fly up and grab a spacecraft that was never designed to be grabbed changes the maths for every satellite up there. Rescue instead of write-off. Repair instead of replace. The same arms that catch Swift could one day drag dead satellites out of harm's way.
And the price tag matters as much as the robot. The whole mission, launch included, costs NASA about $30 million, built by a small company in under a year. If it works, it's a glimpse of a faster, cheaper way of doing business in orbit.
So spare a thought at 10:09 this morning for an ageing airliner over the Pacific, dropping the last of an old breed of rocket, carrying a fridge-sized robot on its way to catch a falling telescope. Space doesn't do many rescue stories. Today we get one.
Sources:
- Weather Delays Launch of Mission to Boost NASA's Swift — NASA
- NASA to launch rescue mission July 2 to save Swift space telescope from burning up in Earth's atmosphere — Space.com
- Pegasus XL set to air launch Swift Boost Mission to save NASA space telescope — NASASpaceFlight
- NASA races to save aging Swift telescope from falling back to Earth with daring rescue mission — PBS News
- Swift Boost Mission — NASA
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