After 'tour de force' mission, NASA crew says goodbye to Hubble

With the final spacewalk of their mission complete, the seven-astronaut crew of the space shuttle Atlantis today is preparing to release the Hubble Space Telescope.

NASA Astronauts Drew Feustel and John Grunsfeld completed the mission's fifth and final spacewalk on Monday, replacing one of Hubble's three Fine Guidance Sensors, and installing a second three-battery module and a stainless steel thermal protection blanket on three of the telescope's bay doors.

Hubble should resume peering into the cosmos again in about three weeks.

"This is a really tremendous adventure that we've been on, a very challenging mission. Hubble isn't just a satellite -- it's about humanity's quest for knowledge," said Grunsfeld outside the shuttle's airlock at the end of the mission. "A tour de force of tools and human ingenuity. On this mission in particular, the only way of finding the limits of the possible is by going beyond them into the impossible. On this mission, we tried some things that some people said were impossible. We've achieved that, and we wish Hubble the very best."

The astronaut also said he hopes the Hubble telescope will be able to use its new instruments to "unlock further mysteries of the universe."

The crew of the Atlantis has been in space for nearly eight days on a mission to repair and upgrade Hubble. The work is expected to not only keep the orbiter running for another five years at least, it's expected to make the telescope more powerful than ever and enable it to make more and more important discoveries.

With the spacewalks behind them, the NASA astronauts this morning prepared the telescope, which was held in the shuttle's payload bay while it was serviced, for its return to orbit. Mission Specialist Megan McArthur then operated the robotic arm, which grappled the telescope at 6:45 a.m. EDT today. She maneuvered Hubble to a point above the shuttle bay before releasing it a little more than two hours later.

After the release, Commander Scott Altman and Pilot Gregory Johnson maneuvered Atlantis away from the orbiter.

Later in the day, the shuttle crew and NASA's ground team will turn their attention to examining the shuttle's heat shield system.

A day after the shuttle Atlantis blasted off last week, the crew used the robotic arm and an attached sensor to inspect critical areas of the shuttle's thermal protection system, especially on the craft's nose and the edges of its wings. NASA reported that day they had found multiple dings on four different heat shield tiles. The damage, the space agency reported, looked to be minor.