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Heavenly Views

By Martha Pickerill

The space shuttle Columbia blasted off into a cloudless Florida sky last Friday morning. Its mission: to jazz up the Hubble Space Telescope with 6,000 pounds of new equipment. If the mission succeeds, the Hubble will soon send to Earth the sharpest pictures of outer space ever seen. "Hubble's up there ready for us," said Commander Scott Altman. "And we're ready to go to work."

Up Above the World So High
The Hubble Space Telescope has been peering into distant corners of the universe since 1990. The $2 billion scope is in orbit more than 300 miles above Earth.

Hubble's position beyond Earth's atmosphere gives it a crystal-clear view of space. The gases that make up Earth's atmosphere interfere with our view of the heavens, even through the most powerful ground telescopes. So far, Hubble has taken more than 420,000 shots of cosmic events. These wondrous sights include stars being born, galaxies crashing into one another, stars exploding and razor-sharp views of the planets.

Hubble's space pictures have given astronomers the best information ever about our universe. It's hard to believe that the whole project was nearly a disaster! Soon after Hubble was placed in orbit, scientists discovered that its vision was blurry because it was built with a flawed mirror. In a daring 1993 mission, astronauts corrected Hubble's vision with additional mirrors and fixed other problems with the telescope. "Hubble is an American comeback story," says Anne Kinney, NASA's astronomy director.

More Pictures, More Power
Soon, Hubble should be able to send back even more dramatic views of the universe. This mission is more complicated than the one in 1993. The crew plans to tune up the big scope during five space walks. A new Advanced Camera for Surveys will double Hubble's field of vision. The 800-pound camera is 10 times more powerful than the old one. It should capture objects that are smaller, fainter and farther away than anything yet seen in space.

Smaller, sturdier solar arrays—the winglike panels that collect the sun's energy to power the telescope—will replace the sun-damaged and debris-battered old panels.

A new power control unit will send energy to all parts of the telescope. The astronauts will replace part of the system that steers the Hubble. They'll also install a cooling system in hopes of reviving another Hubble camera, which hasn't worked since 1999. After all of the new parts are in place, Columbia will boost Hubble a bit higher above Earth. Then the shuttle's robot arm will nudge the telescope back into orbit.

Astronauts trained for this mission for two years. They practiced removing, adjusting and replacing telescope parts without seeing or feeling them—just as they must do in space.

One crew member, Richard Linnehan, is a veterinarian as well as an astronaut. He has operated on elephants, whales and walruses! Fixing Hubble might be similar work, he says. "It's like doing surgery on a big beast."

The riskiest space walk will come when the astronauts replace the power unit. All of the telescope's power must be shut down-something never attempted in the 12 years that Hubble has been in orbit. "If something's working well, you don't turn it off and just hope it comes back on," said Ed Weiler, NASA's space science chief. "It is a risk that we've never faced before."

Hubble's Future
One more trip to rev up the Hubble is planned for 2004. If all goes well, the trusty scope will keep its eye on the skies until 2010. Then it will be loaded into a shuttle and returned to Earth. It will spend its retirement at the National Air and Space Museum in Washington, D.C. By then, an even grander machine, the Next Generation Space Telescope (NGST), should be in orbit. Scientists say the NGST will offer even sharper views of galaxies far, far away.

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