No Go on the Space Shuttle Yo-Yo

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.