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- THE WEEK, Page 17HEALTH & SCIENCENo Go on the Space Shuttle Yo-Yo
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- Astronauts are forced to abandon a daring, difficult experiment
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- It was supposed to be another space spectacular, the kind
- NASA used to pull off like clockwork: astronauts aboard the
- shuttle Atlantis had plans to dangle a half-ton satellite on a
- 20.1-km (12 1/2-mile) tether, forming the biggest single orbiting
- object in history. But like so many of the space agency's
- ambitious projects lately, this one didn't quite work out. The
- Italian-made satellite rose properly from the shuttle on a 10-m
- (39-ft.) boom, but the astronauts couldn't pull out its
- auxiliary power cord. When they finally got the cord out and
- began unreeling the satellite, the tether that kept it attached
- to the shuttle paid out for about 260 m (850 ft.) -- and then
- jammed, like a badly wound fishing reel. It jammed again when
- they tried to pull it in, and rather than risk a spacewalk to
- try and loosen it, ground controllers decided to pull the
- satellite back inside.
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- By stretching the copper-cored, shoelace-thin tether
- within the earth's magnetic field, NASA scientists expected to
- generate up to 5,000 volts of electricity. Ultimately, such
- tethers could not only power spacecraft but also secure
- counterweights that could be set spinning to create artificial
- gravity.
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- Still, it might have been worse. NASA has had little
- experience with tethered satellites, and no one was sure how
- this one would behave. There was some fear that it would wobble
- wildly at the end of its cord. The astronauts were prepared to
- cut the whole thing loose if the experiment threatened the
- shuttle. To the relief of the Italian Space Agency, that didn't
- happen, and the $379 million system may one day fly again.
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