Astronauts Snare Telescope, Make First of 5 Spacewalks

Speeding high above the South Pacific, shuttle astronauts deftly snared the $1.5-billion Hubble Space Telescope before dawn Saturday and then, in the first of five planned spacewalks, stepped out into the void to repair its sense of balance.

Barring complications--NASA has spent 18 months rehearsing for dozens of potential emergencies--Endeavour’s astronauts expected to leave the spacecraft on a second walk tonight to replace the Hubble’s bent and flapping golden solar wings. And on Monday, the crew members were to begin restoring the Hubble’s flawed optics by installing an advanced planetary camera designed by Pasadena’s Jet Propulsion Laboratory.

The mission’s record number of spacewalks is the heart of NASA’s $629-million effort to cure the observatory of its potentially fatal mechanical defects and hopefully to salve the space agency’s wounded pride.

By proving that men and women floating in space can perform complicated and physically demanding maintenance tasks, National Aeronautics and Space Administration officials said, the Hubble repair mission also will pave the way for construction and routine servicing of the planned space station and other orbiting outposts in the next century.

“This will demonstrate our ability to service satellites in orbit,” said Brewster Shaw, director of space shuttle operations. “Looking down the road to the space station, we are going to be doing a lot of this.”

It is not the first time that astronauts have repaired satellites in orbit. The sight of people in puffy white spacesuits wrestling satellites in slow motion has become a powerful testament to the abilities of astronauts to improvise repairs in orbit, in triumphs of old-fashioned muscle over the breakdowns of high technology.

NASA crews performed the first satellite retrievals and repairs almost a decade ago. Only last year, astronauts captured an Intelsat communications satellite by hand and dragged it aboard the shuttle.

But the Hubble was designed from the beginning to be easily serviced by hands made clumsy by stiff spacesuit gloves working where low gravity and vacuum make even the simplest twist of a wrench a complex undertaking.

Many of its parts were designed to be modular, standardized and easily accessible, ranging from small fuses to the scientific instruments themselves. The telescope’s gleaming silver cylinder even has 225 feet of handrails and 31 footholds to aid floating service crews.

The observatory’s astronomical cost--annual operational expenses are running at about $300 million--was justified, in part, because astronauts working from the shuttle could keep it operating for 15 years or more. Endeavour’s astronauts will need all of the help they can get this week. The slightest misstep, careless elbow or over-energetic twist of a bolt could spell disaster, NASA officials said.

“The No. 1 rule . . . is don’t hurt yourself,” said astronaut Jeffrey Hoffman, one of Endeavour’s four mission specialists, in a pre-launch briefing. “No. 2 . . . is don’t break anything that isn’t already broken.”

Hoffman and astronaut Story Musgrave started to put the servicing idea to its first rigorous test during the mission’s initial six-hour spacewalk, which began about 7:45 p.m. Saturday and was scheduled to end at 3:07 a.m. today.

With Hoffman riding the shuttle’s robot arm and Musgrave anchored to a foothold on the telescope, they expected to unbolt an access door with a programmable power wrench and replace several failed gyroscopes that the Hubble needs in order to keep its position and track stars. They were also to replace two electronic control units and, if there was time, change eight fuses.

Tonight, astronauts Kathryn C. Thornton and Thomas D. Akers are scheduled to replace the telescope’s solar panels. Engineers at the European Space Agency have designed new deployable solar arrays to eliminate the unwanted “jitters” that set in every time the Hubble moves in and out of daylight during its 90-minute orbits.

Since its launch, Hubble has traveled about 522 million miles and, despite its limitations, made about 45,000 observations for more than 1,000 astronomers.

Endeavour caught up with the Hubble just before 1 a.m. PST on Saturday.

Steering by hand, shuttle commander Richard Covey inched Endeavour to within 35 feet of the Hubble, where Swiss astronaut Claude Nicollier took hold of the 43-foot telescope with the Canadian-built mechanical arm and berthed it in the shuttle’s cargo bay.

“Houston, Endeavour has a firm handshake with Mr. Hubble’s telescope. It’s quite a sight,” Covey radioed to mission controllers at the Johnson Space Center in Houston.

“It’s one fantastic job you guys,” responded astronaut Susan Helms in Houston as the controllers applauded. “We really enjoyed watching over your shoulders on this one.”

Until Saturday morning, the shuttle crew had not encountered any complications more serious than a leaking water bag on one of their four $10-million spacesuits.

But once the Endeavour astronauts inspected the telescope, they saw what could be the first sign of trouble. One of the Hubble’s nearly 40-foot-long wings was warped, with two distinct kinks in a supporting strut that could make it impossible to roll up the solar panel as planned.

Hoffman first spotted the damaged panel as he examined it through binoculars at a distance of 10 miles. “The right-hand solar array, as we can see it, is bent way over, so apparently we have a dynamic situation,” he reported.

NASA officials said that as a last resort, they had plans to jettison the damaged solar array in case the panel cannot be rolled up into its carrier early this morning in preparation for their removal Monday. Otherwise it would be stowed aboard the shuttle for return to Earth.

Derek Eaton, the European Space Agency project manager for the Hubble mission, was unconcerned. “We half anticipated this,” he said Saturday. “The solar array should still retract OK without any manual work by the astronauts.”

Eaton would not rule out the possibility the damage had been caused by a micrometeorite, but said that was a “a long shot.”

Hooking Up With Hubble

Astronauts aboard the shuttle Endeavour deftly snared the flawed $1.5-billion Hubble Space Telescope. Later, in the first of five planned spacewalks, they stepped into space to repair the telescope’s sense of balance.

Details of tonight’s spacewalk, to take place sometime between 9 p.m. and 3 a.m. Pacific time.

* Astronauts: Kathryn C. Thornton and Thomas D. Akers

* Goal: Replace both solar energy panels.

* Procedure: After ground controllers order onboard motors to roll up the flexible solar panel blankets, one spacewalker standing on the shuttle’s mechanical arm will undo three latches and remove the entire assembly. The shuttle’s mechanical arm will then be swung down to the cargo bay, letting the astronaut drop off the old array in a special holder and pick up a new one. The arm will swing back to the telescope and the two astronauts will install it. The second array will then be removed and its replacement attached in the same fashion.

* Where to watch: CNN and C-SPAN will offer live coverage.

Source: NASA