STS-125 Commander Scott Altman sits in the cockpit of the Shuttle Training Aircraft before taking off to practice shuttle landings.

On the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida, STS-125 Commander Scott Altman, wearing his launch-and-entry suit, sits in the cockpit of the Shuttle Training Aircraft before taking off to practice shuttle landings. He is preparing for launch of space shuttle Atlantis, scheduled for 2:01 p.m. EDT on May 11. On Atlantis’ STS-125 mission, NASA's Hubble Space Telescope will be serviced for the fifth and final time. The flight will include five spacewalks during which astronauts will refurbish and upgrade the telescope with state-of-the-art science instruments. As a result, Hubble's capabilities will be expanded and its operational lifespan extended through at least 2014. Photo credit: NASA/Kim Shiflett