A Tiny Space Tug Blasts Off to Save a Falling Telescope!
Quick Summary
NASA launched a small robotic spacecraft on July 3 to rescue a falling space telescope before it burns up in Earth’s atmosphere. The rescue robot is called LINK, and it rode to space on the last-ever flight of a very special rocket. If everything goes to plan, LINK will grab the telescope and push it back up to a safe height.
What Happened?
High above Earth, a famous space telescope is slowly falling. It is called the Neil Gehrels Swift Observatory, or just “Swift.” NASA launched Swift back in 2004. That is more than 22 years ago! In all that time, Swift has been watching the universe for powerful explosions called gamma-ray bursts. These bursts are the biggest explosions in the whole universe.
Swift was never meant to last this long. It was only supposed to work for two years. But it kept going strong, so NASA kept using it.
Here is the problem. Earth’s atmosphere — the thin blanket of air around our planet — reaches very high up into space. Even at great heights, there is just a tiny bit of air. That tiny bit of air slows Swift down a little every single day. It is like trying to run through water instead of air. Over many years, Swift has sunk lower and lower. Right now it is dropping about five miles every month.
If nothing is done, Swift will sink so low that it will tumble back into the thick atmosphere and burn up like a shooting star — and take 22 years of science with it.
So NASA hatched a rescue plan. Engineers built a small robotic spacecraft called LINK. It is about the size of a large washing machine. LINK has three robot arms, solar panels as long as a school bus is wide, and special ion thrusters that shoot out a stream of charged gas called xenon to push it through space.
On the morning of July 3, LINK launched from a tiny island called Kwajalein Atoll in the South Pacific Ocean. It did not ride a regular rocket from a launch pad. Instead, it was bolted under the belly of a specially modified jet airplane called Stargazer. Stargazer climbed to about 40,000 feet — higher than most airplanes fly — and then dropped a rocket called Pegasus XL. The rocket’s engines fired, and LINK zoomed up to orbit.
That Pegasus rocket is now retired. This was its very last flight ever, after 36 years and 46 missions.
Now LINK is in orbit. Over the next few weeks, it will test all of its systems. Then it will slowly fly toward Swift, look it over carefully, and reach out with its robot arms to grab it. After that, LINK will spend weeks slowly pushing Swift higher and higher until it is safe again — maybe for another ten years.
Why Does It Matter?
This mission is special for two big reasons. First, it could save a $250 million telescope that is still doing amazing science. Scientists do not want to lose it.
Second, this has never been done before. No commercial robot spacecraft has ever grabbed a NASA satellite that was not built to be grabbed. Swift has no special handles or docking ports. LINK has to figure out where to hold on all by itself. If LINK succeeds, it will prove that future broken or sinking satellites can also be rescued. That is a huge deal for the future of space.
The entire rescue cost about $30 million. That sounds like a lot, but it is much cheaper than building a brand-new telescope. Think of it like fixing a bicycle for $10 instead of buying a new one for $100.
Big Words
- Orbit: The curved path a spacecraft follows as it travels around Earth, like a ball on a string spinning around your hand.
- Atmospheric drag: The slowing-down effect on spacecraft caused by tiny bits of air high above Earth, the same way wind slows you down when you ride your bike into it.
- Ion thruster: A super-efficient engine that pushes a spacecraft by shooting out charged particles called ions — like a very gentle but steady breath that pushes the craft through space.
- Gamma-ray burst: An enormous explosion in deep space that releases more energy in a few seconds than our Sun will produce in its entire lifetime.
- Rendezvous: When two spacecraft carefully navigate to meet each other in space — like two boats slowly steering toward each other in the middle of the ocean.
Fun Fact
Swift is called Swift because it can spin around to point at a new target in under two minutes. Most big telescopes take hours or even days to reposition. That super-fast spin lets Swift catch explosions in space before they fade away!
Think About It
If you were designing a space robot that had to grab a satellite it had never touched before, what would you put on its arms to help it hold on safely?
Sources
- NASA Science — Swift Boost Mission
- Space.com — NASA launches rescue mission to save Swift space telescope from burning up in Earth’s atmosphere
- CBS News — Mission launched to save falling Swift space telescope
- CNN — A daring rescue mission launches to save a falling NASA observatory
- Northrop Grumman — Northrop Grumman’s Pegasus Rocket Powers Mission to Extend NASA’s Swift Observatory
- TechTimes — Pegasus XL Final Flight Delivers $30M Rescue for $500M Swift Observatory