CAPE CANAVERAL, Fla. -- The Atlantis astronauts rocketed into orbit Friday for the most complex flight in shuttle history, a daring mission to cast a tethered satellite 12 miles into the sea of space next week and then to reel it back aboard.
Whether the astronauts can haul in the science data they are trolling for with their tethered satellite remains to be seen becuse no one knows exactly how the Italian satellite, connected to Atlantis by a pencil- thin cord, will behave in the weightlessness of space.
While NASA managers say the odds of a collision or other mishap are minimal, the astronauts have been cleared to cut the line if their safety is threatened at any time.
'Mission success is deploying the satellite, getting the data and after that point, if safety dictates it, or at any time that it's dictated, we'll have to sever the cable,' said shuttle chief Jeremiah Pearson. 'But if we get the satellite out and get the data, that's success. If they happen to bring (the satellite) back, we're heroes.'
With its three main engines roaring with power, Atlantis's twin solid-fuel boosters ignited with a rush of brilliant orange flame 48 seconds after the scheduled time of 9:56 a.m., quickly pushing the 4.5- million-pound space freighter skyward through blue skies with scattered clouds.
At the controls were commander Loren Shriver, 47, and co-pilot Andrew Allen, 36. Their crewmates are Swiss astronaut Claude Nicollier, 47, Marsha Ivins, 41, Jeffrey Hoffman, 47, Franklin Chang-Diaz, 42, and Italian astronaut Franco Malerba, 45.
The launch was delayed 48 seconds by a minor glitch at the T minus 5- minute mark -- a computer detected a switch had not yet been thrown to open a hydrazine fuel tank to one of the three auxiliary power units that provide pressure to the shuttle's hydraulics.
Eight-and-a-half minutes after liftoff, Atlantis slipped into its planned preliminary orbit. A smaller rocket firing 41 minutes into the flight put the ship in a circular orbit 265 miles up.
'It was really a piece-of-cake countdown,' said Brewster Shaw, NASA deputy manager for the shuttle program, calling the seven-day mission 'really neat science.'
'We are going to learn something brand new that we've never done before by letting a satellite out on a tether,' he said.
The goal of the 49th shuttle mission, the fifth of nine planned for 1992, is two-fold. On Saturday, the astronauts are scheduled to launch a European satellite called Eureca that is packed with materials science and biochemical experiments.
The satellite, part of a $429 million European Space Agency project, will be brought back to Earth next April by another shuttle crew. NASA was paid about $29 million for the launch and retrieval.
But the clear highlight of Atlantis's mission is the deployment Monday of the Tethered Satellite System, or TSS. The spherical satellite is the centerpiece of a $379 million joint U.S.-Italian project to study the interaction between Earth's magnetic field and the extreme upper ionosphere, a region of the atmosphere dominated by electrically charged particles.
Attached to the shuttle by an electricity-conducting cable as thin as a clothes line, the 5-foot-wide, 1,200-pound TSS spacecraft will be reeled out 12 miles, remaining attached to Atlantis much like the lure on the end of a fishing line.
As the cable trolls through Earth's magnetic field, negatively charged electrons in the ionosphere will be attracted to the surface of the satellite and flow down the tether to the shuttle's cargo bay.
They then will be fired back out into space, completing a gigantic 5, 000-volt circuit generating about 2,500 watts of power, enough to run the lights and appliances in an average house.
The goal of the unprecedented project is to learn more about how to control satellites connected by cables and to confirm theories about how electric currents can be generated and utilized in space.
Such technology one day could lead to new power sources for future space stations and, if two tethered satellites were set spinning, allow engineers to design spacecraft that could utilize what would amount to artificial gravity for long-duration voyages to Mars or beyond.
But it will not be easy. Engineers first must learn how to control a tethered satellite in the weightlessness of space where uncontrolled motions could, in time, escalate into serious trouble.
While the chances of a collision with TSS are remote -- the satellite will be moving extremely slowly throughout its 30-hour deployment -- the astronauts can easily fire special cutters that would instantly sever the tether, eliminating any chance of a collision.
'The initial reaction that most people have when they learn that we're about to attach the shuttle to a satellite by a (12-mile-long) rope is...'Oh my God, why would anybody want to do that?'' Hoffman said in a recent news conference.
'The first thing you think about is, what's going to happen to all that rope, what's going to keep it in the place? What we've learned is that there are some very clear physical laws that we believe the tether should follow. We feel extremely confident that we have addressed adequately all the safety concerns.'
Even so, the actual behavior of the tether could not be simulated in Earth's gravity and surprises are no doubt in store for the astronauts. But Shriver downplayed the odds of a serious problem.
Atlantis is scheduled to land at the Kennedy Space Center in Florida next Friday at 8:05 a.m. EDT.
