Two U.S. astronauts ventured outside the shuttle Columbia Monday to begin a week of spacewalks aimed at improving the Hubble Space Telescope. The astronauts replaced the first of two new solar wings that will give more power to the observatory.
Astronauts John Grunsfeld and Rick Linnehan floated outside Columbia for seven hours to exchange one Hubble solar array for a new one. An alternate pair of spacewalking astronauts will repeat the task with the the other array during a second spacewalk Tuesday.
Unlike the old flexible solar wings, the new ones are rigid and smaller, causing less drag. They also provide 20 percent more power than the old ones, providing enough electricity to serve all of Hubble's instruments at once.
Later in the week, the astronauts will install a new generator to distribute the power, a new gyroscope to aim Hubble, and a new camera to boost the observatory's visual strength to let it see closer to the edge of the universe.
The crew also hopes to revive a long dormant infrared camera that sees celestial objects through the dust of space.