Headed after Hubble

Shuttle on mission to repair telescope

CAPE CANAVERAL, Fla. -- The Endeavour astronauts raced after the orbiting Hubble Space Telescope on Thursday after an early morning launch for the most ambitious shuttle mission ever.

The two high-flying spacecraft were on course for their scheduled rendezvous early Saturday.

Once the shuttle crew has grappled the $1.5 billion space telescope with Endeavour's robot arm, the astronauts plan to position the four-story observatory vertically on a massive rotating workbench in the ship's cargo bay.

The first of the five to seven lengthy spacewalks planned by the astronauts to correct the observatory's optical flaws and make other major repairs is scheduled to begin late Saturday night.

"It's really a great relief to have this mission on orbit now," said Loren Shriver, the former astronaut who chairs NASA's mission management team.

The ship roared from its Kennedy Space Center launch complex at 3:27 a.m., Houston time, Thursday, creating a spectacular night-time display.

"What a beautiful way to start the mission," Endeavour commander Dick Covey radioed mission control.

The ship's six-man, one-woman crew, dozens of ground controllers, hundreds of engineers and technicians have trained and prepped for a year to conduct the complex mission, with its time-critical rendezvous, exhausting spacewalks and exacting repair strategy.

The space agency is hopeful its success will temper the embarrassment that followed NASA's disclosure three years ago that the telescope had been launched with an undetected flaw in its 94-inch wide primary mirror. The debacle created a political and public millstone the agency is eager to cast aside.

"This mission is higher profile than most," said Shriver, who commanded the April 1990 shuttle flight that lofted the telescope into orbit. "I have big confidence we will get this done."

Among those most eager not to be overlooked by the media and public interest in the mission are the international teams of astronomers who use the telescope.

"I thought this day would never come," said NASA chief astronomer Ed Weiler, who has mounted an often frustrating campaign to preach the scientific accomplishments of the telescope. "I can't wait to vindicate this program."

Endeavour settled into a 354-mile-high orbit after launching, one of the loftiest of the 12-year-old shuttle program.

The astronauts began their pursuit about 6,000 miles behind and slightly below the space telescope. Two major shuttle maneuvers closed the gap to 2,900 miles late Thursday and slowed the closing rate.

A half-dozen more carefully planned maneuvers were planned to accomplish Saturday's rendezvous.

Endeavour's mission is commanded by Covey, a 47-year-old Air Force colonel. His flight crew includes pilot Ken Bowersox, a 37-year-old Navy commander; robot arm operator Claude Nicollier, a 49-year-old Swiss astronaut; and a four-member spacewalk repair team.

Led by physician Story Musgrave, 58, the repair team includes astronomer Jeff Hoffman, 49, Air Force Lt. Col. Tom Akers, 42, and physicist Kathy Thornton, 41.

The astronauts have adopted a topsy-turvy work schedule, starting their 16-hour days as most Americans leave their jobs for home each evening.

They comprise the most experienced crew of astronauts ever assembled for a space mission, with 23 space flights among them. Musgrave has been an astronaut for a quarter-century and is the first to fly five shuttle missions.

Each of the spacewalkers has logged at least one previous excursion in a space suit.

The space agency is betting the experience will count as the fliers attempt to tackle 11 repair tasks, seven of which are considered essential to the full success of the mission.

Those tasks include the installation of new gyroscopes and electricity-producing solar arrays as well as the the grand piano-sized Wide Field Planetary Camera and the refrigerator-sized Corrective Optical Space Telescope Axial Replacement -- the two components designed to correct the infamous optical flaw.

The spacewalkers also plan to install new magnetometers, a drive mechanism to keep the solar panels trained on the sun as the observatory circles the Earth and a component that will expand the telescope's computer memory.

With the optical repairs, astronomers expect to study in more detail the faint distant objects that were among the earliest inhabitants of the cosmos, more accurately estimate the age of the universe and prove the existence of black holes.