A commercial robotic spacecraft called LINK launched on an emergency mission to save NASA’s Neil Gehrels Swift Observatory, which has been slowly falling toward Earth, on July 3, 2026. Over the coming weeks, LINK, built by Katalyst Space Technologies, will try to grasp the telescope, then spend months raising it to a safer orbit.

For most of the space age, satellites have been disposable: moved aside or replaced when they ran low on fuel or failed. That wasn’t much of an issue decades ago, when orbit was far less crowded. Now, space surveillance networks track tens of thousands of human-made objects, and the European Space Agency estimates that more than 1.2 million pieces of satellite and spacecraft debris larger than half an inch (1 centimeter) are in orbit. Even chunks that small are large enough to cause severe damage in a collision.

You might say “just clean up the junk” because space debris looks motionless in photographs. But as a Ph.D. candidate researching satellite servicing, I know that the hardest part of removing a dead satellite before it breaks apart into new debris is not reaching it – it is understanding how it moves, how to approach without hitting it, and controlling the instant that two free-flying objects touch.

A tow hook changes the problem

So, how do you catch a dead or broken satellite? The spacecraft doing the catching is a servicer: a robotic mechanic that flies up to refuel, repair or move a disabled satellite.

Some satellites, called prepared satellites, are easier to catch. They carry a built-in feature that works like a........

© The Conversation