ROANOKE TIMES
Copyright (c) 1996, Roanoke Times
DATE: Monday, February 26, 1996 TAG: 9602270051
SECTION: NATIONAL/INTERNATIONAL PAGE: A-1 EDITION: METRO
DATELINE: CAPE CANAVERAL, FLA.
SOURCE: The Washington Post
A $440 million science satellite was lost in space Sunday night when a slender tether holding it to the shuttle Columbia suddenly snapped, sending the small instrument package sailing into oblivion in a costly failure for NASA and the Italian Space Agency.
``The tether has broken at the boom!'' astronaut Jeffrey Hoffman suddenly exclaimed when the cable broke. ``The tether has broken. It is going away from us. Get it on the TV, Claude, please get it on the TV! The tether has broken.''
Astronaut Claude Nicollier quickly aimed the shuttle's television cameras at the receding satellite to document its departure. In stark, black-and-white footage, the satellite could be seen slowly sinking in the black night of space, trailing 12 miles of jumbled, now-useless tether in its wake.
Columbia and its seven-man crew were not in any danger from the incident. The cable broke inside a telescoping 39-foot launching boom extending out of the shuttle's cargo bay like a giant fishing rod. About 30 feet of tether remained inside the boom, but the rest pulled free with the satellite.
Putting their disappointment aside, the astronauts and flight controllers worked to inspect the boom to make sure the remaining cable would not prevent the tower's retraction later. The boom can be jettisoned if necessary.
The astronauts were in the process of unreeling the Italian Tethered Satellite 12.5 miles into space when the tether snapped.
The idea was to demonstrate a novel technique for generating electrical power using the tether's passage through Earth's magnetic field and electrically charged ionosphere. Other applications included futuristic methods for raising or lowering a satellite's orbit without using rocket power.
The deployment had proceeded like clockwork from the point the satellite was released at 3:45 p.m. Sunday, and excited scientists watched their instruments eagerly as electrons began flowing through the tether exactly as planned.
``The tether is not straight. It makes a huge bow,'' Hoffman observed at one point. ``It goes out toward the nose of the shuttle and then makes a huge curving arc to come back to the satellite. It's quite remarkable. When the sun rises, the satellite is the brightest star in the sky.''
``That's awesome,'' replied astronaut David Wolf in Houston. ``We are really pushing out tether right now.''
``Yeah, we're pushing out lots of tether, and we're pulling down a lot of electrons,'' Hoffman replied.
``Sitting close to 1,600 volts,'' Wolf said. ``And that's at 420 milliamps, Jeff.''
But suddenly, with the satellite about 12 miles out, the tether snapped without warning. The satellite was propelled away at nearly 100 mph relative to the shuttle, almost as if the tether had been a rubber band.
``Those are some tether dynamics we did not want to see,'' Wolf said later, watching a videotape of the satellite's departure.
``Well, we have demonstrated you can generate a lot of electricity with a tether,'' Hoffman said quietly. ``Unfortunately, we've also demonstrated that you can use tethers to launch a satellite into a much higher orbit.''
``We can see it picked up about an 80-foot-per-second boost,'' Wolf said.
``Without using any propel- lant,'' added Hoffman.
But that was no consolation to the scores of men and women in the United States and Italy who labored for 10 years on the tethered satellite project and who had such high hopes for its success.
In 1992, the crew of the shuttle Atlantis - including four members of Columbia's current crew - failed to fully deploy the satellite when the tether jammed after just 843 feet of cable had played out.
NASA and the Italian Space Agency spent $60 million making repairs and planning the current mission, only to see their hopes dashed Sunday.
``We did get a large amount of good data, and nothing can diminish the great job all the people on this team have done,'' Wolf radioed Columbia's crew later.
LENGTH: Medium: 79 lines ILLUSTRATION: PHOTO: AP. Before it was reeled out on the 12-mile cable thatby CNBbroke, the satellite perched on this 39-foot boom. The $440 million
satellite is now lost in space.