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Space Tethers: Slinging Objects in Orbit?

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Space Tethers: Slinging Objects in Orbit?

Space Tethers: Slinging Objects in Orbit?

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  • <iframe src="" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
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Okay, consider this question. What do you get when you combine a high school library, a ballistic missile, and a machine that makes sexy underwear? The answer, and there really is an answer, is a woven rope more than half a mile long called a space tether. It is scheduled to blast off tomorrow, and it's the focus of our Monday report on the business of technology.

NPR's Nell Boyce has more.

NELL BOYCE: When Rob Hoyt was in high school, he liked science fiction. One day he was in the library, and he picked up a book called "The Flight of the Dragonfly."

Mr. ROB HOYT (Creator, Space Tether): And I looked at the author blurb in the back and it said something like, you know, Robert L. Forward spends half of his time writing science fiction and the other half of his time working on advanced space propulsion technologies for NASA. And you know, I read that and I thought, boy, that's the job I want to have.

BOYCE: So Hoyt got a degree in physics and went on to graduate school. That's when he went to a lecture by that same science-fiction author. The talk was about space tethers.

Now, for 50 years people have relied on rockets to move things around in space. But rocket fuel is expensive and heavy. As Hoyt sat in the lecture hall, he heard how much easier it would be to just fling things around using long tethers.

Mr. HOYT: It's sort of like using the techniques of Tarzan to move around in space. You're basically grabbing onto a long, high-strength rope and using it to swing you from one place to another.

BOYCE: But not yodeling or whatever it is Tarzan does.

(Soundbite of laughter)

Mr. HOYT: No. No one could hear you yodel in space.

BOYCE: But, the lecturer said, there was one problem.

Mr. HOYT: At the end of his talk, he said, well, but none of this will really work right now because space tethers will get cut by orbital debris.

BOYCE: In other words, a tether would get snipped in two by space junk.

Mr. HOYT: There are just so many millions and billions of flecks of paint and dust flecks and tiny little micro-meteorites zinging around in orbit at incredible velocities.

BOYCE: The lecture got Hoyt thinking. Instead of studying for his graduate exams, he began designing a new kind of space tether. It's made of more than one strand, like a woven net or a cat's cradle. If one strand gets cut, the others stay intact.

Hoyt wrote a letter to that science fiction author, Robert Forward, and eventually they started a company, Tethers Unlimited, which has gotten funding from NASA. Hoyt says they start with light but strong fibers, like Kevlar. Then they weave them together using a computerized machine.

Mr. HOYT: That's normally used for fabricating things like lacy edgings on, you know, Victoria's Secret undergarments. We've developed ways to use that to braid the multi-line tether structure that we're testing in space.

BOYCE: Soon, three tiny satellites will blast off from Kazakhstan on a modified Russian missile. Once in space, the satellites will deploy the tether. It's half a mile long and looks like a thin net made of gold dental floss. The tether will be anchored by a satellite at each end. Hoyt says the third satellite will crawl up and down the tether, taking pictures.

Mr. HOYT: And we'll then inspect them to see over a course of several months how many cuts the tether experiences.

BOYCE: Engineers have tested other tethers in space. But this will be first experiment in nearly a decade.

Mr. LES JOHNSON (NASA): I'm excited about it. The data that they'll collect from this, if it's successful, is going to be very useful as we look at the next generation tether system.

BOYCE: Les Johnson is an expert on new propulsion technologies at NASA's Marshall Space Flight Center. He thinks tethers have real potential. But he says it will be a while before they are used to move satellites or other things, because they are such a radically different approach.

Mr. JOHNSON: Not that we're afraid of things new; it's just before you put them on a system, they've got to be demonstrated and proven and you've got to have a lot of confidence in them. And we're still in the stages where we're proving this out.

BOYCE: If all goes well with the first experiment, Tethers Unlimited would like to send up another satellite. This one would spin around like a slingshot. Its tether would be nine miles long, and could toss a small object to the moon.

Nell Boyce, NPR News.

INSKEEP: And if you want a close-up look at the proposed space tether, just sling on over to

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