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Time - Man of the Year
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1993-04-08
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THE WEEK, Page 17HEALTH & SCIENCENo Go on the Space Shuttle Yo-Yo
Astronauts are forced to abandon a daring, difficult experiment
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.
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.
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.