Spacewalkers easily pull off tricky Hubble fix

— -- It was supposed to be one of the toughest spacewalks in history.

Instead, two astronauts nimbly polished off an unprecedented and tricky job on Saturday's outing into space: fixing a priceless Hubble Space Telescope camera that broke in 2007.

Astronaut John Grunsfeld said before his mission that repairing the camera, the Hubble's most valuable, would be a "nailbiter." But he pulled off the repair at a rapid-fire pace, without so much as a pause. He and spacewalking partner Andrew Feustel worked so quickly that they got an hour ahead of schedule.

During their spacewalk, Grunsfeld and Feustel also breezed through the installation of the new Cosmic Origins Spectrograph, which will allow scientists to study the composition and structure of the universe.

"Nice work, guys. Congratulations," said the spacewalkers' commander, Scott Altman, as they wrapped up their work.

Grunsfeld, Feustel, Altman and four other astronauts blasted into space on space shuttle Atlantis Monday to pay the fifth and final call on the Hubble. Because they'll be the Hubble's last visitors, it's up to them to leave the telescope in good enough shape to last another five to 10 years.

The ease with with Grunsfeld and Feustel dispatched their assignments Saturday was in sharp contrast to the labors of the mission's first two spacewalks. NASA officials had characterized the first two outings as routine, but instead they turned into marathons of frustration and exertion:

•On Thursday, an old Hubble camera refused to budge from its slot, leading Mission Control to fear that its $132 million replacement would have to return to Earth. In the end, Feustel and Grunsfeld succeeded in exchanging the cameras, thanks to new tools and brute strength.

•On Friday, spacewalkers Michael Massimino and Michael Good could not slide a new gyroscope into place on Hubble despite repeated tries. They ended up having to put a spare, refurbished gyroscope in its place.

No such trouble plaugued Grunsfeld and Feustel Saturday. The new $88 million spectrograph glided into place, after the astronauts removed its outdated predecessor without incident.