A Robot With Three Arms Is Racing Up to Catch a Falling Telescope

Professor Pip rummaged in his pockets on the front porch. "Now, where is that — ah! There you are." Out came a long-handled grabber tool with three pinching fingers at the end. From another pocket, a little cardboard model of a satellite, and a paper telescope that he'd carefully balanced on a piece of string.

Mia and Leo plopped down on the wooden bench beside him.

"Today," Pip announced, "we are going to rescue a falling telescope."

Leo's mouth fell open. "From space?"

"From space!" Pip's spectacles slipped down his nose. "There's a real one. It's called Swift. For over twenty years, it has been watching the sky for huge explosions of stars. But its orbit has been getting lower and lower, because of this." He puffed gently on the paper telescope. The string wobbled, and the little telescope tipped lower.

"You blew on it!" Mia laughed.

"Well, that's because — even way up in space — there's still a tiny tiny bit of air. Not enough to breathe, but enough to push on a telescope very slowly, year after year, like a gentle hand always tugging it lower. That's called atmospheric drag. Eventually it would pull Swift all the way down. We don't want that!"

"Can we save it?" Leo asked.

"Watch closely." Pip raised the grabber tool slowly. "A clever team of engineers built a robot named LINK. It's about the size of our refrigerator." He moved the grabber gently toward the swinging paper telescope. "It will fly up there. It will sneak up nice and slow. It will reach out with three little arms…" CLICK went the grabber, catching the paper telescope mid-swing. The kids gasped. "…and gently hold on."

"Then?" asked Mia.

"Then it gives Swift a slow, steady push upward — using something called ion engines, which shoot out tiny streams of fast-moving particles instead of fire. Not very strong! But strong enough, when you push for weeks and weeks, to lift Swift to a safer height."

"Oh!" said Leo. "Like helping a friend who's stuck on the monkey bars — but it takes ages to lift them all the way up!"

"Exactly right, Leo. Slow and steady wins this rescue."

Pip looked up at the bright blue sky. "This has never been done before — a robot catching another spacecraft that was never built to be caught. Curiouser and curiouser, my friends. The next time you look up at night, remember that there is a tiny brave robot up there, chasing after a falling telescope. Now I wonder… what other things in space might we one day rescue?"