Crew prepares to take on Hubble trouble Mission to repair ailing telescope lifts off Dec. 1

November 07, 1993|By Ann LoLordo | Ann LoLordo,Staff Writer

Tomorrow, submerged in an underwater tank in Houston, a team of astronauts will insert a telephone-booth-size device into a replica of the Hubble Space Telescope in a dress rehearsal of The Big Fix -- NASA's $251 million mission to service the space observatory and repair its flawed vision.

Dressed in 250-pound spacesuits, astronauts Kathryn C. Thornton and Tom Akers will take their turn in the buoyancy pool at the Johnson Space Center as part of a marathon, 59-hour simulation of the agency's most ambitious shuttle mission ever, a kind of mega-mile maintenance check of the four-story telescope that is orbiting 380 miles above the Earth.

It will be an often-practiced, well-choreographed preview of the main event -- an 11-day mission aboard the shuttle Endeavour, planned for a Dec. 1 liftoff from Cape Canaveral. The mission -- whose price tag doesn't even include the $378 million cost of launching the shuttle -- encompasses a record-breaking five spacewalks performed by four of the seven-member crew, among the country's most senior and experienced astronauts.

Planned as a routine servicing flight even before Hubble was launched into space April 24, 1990, the mission has become a crucible for the National Aeronautics and Space Administration, an exacting challenge to correct a colossal mistake in the $1.5 billion telescope that has kept the world-class observatory from doing all of the science it was designed to do.

The disappointment was felt strongly at the Space Telescope Science Institute, the center on the campus of Johns Hopkins University that coordinates the astronomical use of the observatory. But it also pushed the institute staff to develop a creative, innovative solution to the problem.

"Hubble is our eyes. It's how we are going to see back to the beginning of the universe," said Dr. Thornton, a 41-year-old physicistwho will be making her third space flight. "It's how we tell what's happened to us in the past and where our universe is going in the future."

Not only should the mission -- if successful -- prolong the life span of Hubble by replacing worn-out parts and expanding its astronomical repertoire, it should enhance NASA's record of space repairs. And it holds the potential to restore reputations that suffered when NASA revealed that Hubble's perfectly polished 8-foot primary mirror was misshapen.

"We know, whether we like it or not, this program will go down in history," said Edward J. Weiler, the chief Hubble program scientist at NASA. "This is the most aggressive and difficult mission NASA has ever tried with the space shuttle. We said we had a way to fix it, and we said we would go up in 1993 and do it . . . and we're going up and do it."

When NASA built Hubble, it envisioned just such missions to ensure the telescope's 15-year life span.

It was made to be touched by human hands -- although these will be in pressurized gloves. Astronauts who might one day blast off into space to fix it were consulted during design of

Hubble. This "user-friendly" telescope sports 225 feet of hand rails and 31 sites to attach foot restraints.

The telescope's tool box -- containing some 91 tools -- snaps into a wall of the shuttle bay for easy access during repairs. And, the astronauts will carry a kind of space tool belt attached to their chest. These space mechanics will be hoisted to those hard-to-reach places by a robotic arm, much like a utility worker in a cherry-picker.

"Although we are dealing with a very complex scientific instrument,our job as astronauts is not a very intellectual task," said astronaut Jeffrey A. Hoffman, 49, an astrophysicist whose first walk in space in 1985 involved rescuing a crippled satellite.

"The challenge has not been intellectually to develop some fundamentally new techniques of working with space physics or celestial dynamics. It's been very nitty-gritty, nuts-and-bolts type work, of trying to figure out how to do a lot of work in a limited amount of time using our mid-1990s spacewalking technology."

In some ways, the work seems the stuff of handymen: turning bolts with a power tool that resembles a cordless drill, removing blown fuses, cranking down on ratchets with wrenches. But make no mistake, the work will be time-consuming and tedious, choreographed in slow motion to protect against jostling sensitive equipment, and executed in weightless, frigid space.

It involves tasks no person has ever accomplished in space, repairs that come none too soon for the telescope's life's work -- peering into the solar system, singling out its so-called "black holes," photographing the cores of galaxies.

In one of the first space walks, Payload Commander F. Story Musgrave, 58, will crawl inside the guts of the telescope and squeeze behind a bank of internal components to replace a pair of Hubble's faulty gyroscopes -- instruments that allow the telescope to remain precisely fixed on an object.

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