Photos: Walking above the clouds
During the first space walk Astronaut Piers J. Sellers hangs from the bottom of a 100-foot Remote Manipulator System/Orbiter Boom Sensor System. The astronauts successfully tested the space crane that will allow them to reach new locations on the space shuttle or International Space Station. See more Discovery photos.
Space station upgrades
During the second space walk, which lasted for almost seven hours, astronauts Michael E. Fossum (center) and Piers J. Sellers (you can see his backpack right) repaired the Mobile Transporter rail car and delivered a spare pump module for the International Space Station.
Astronauts Piers Sellers and Mike Fossum took a third space walk on Wednesday to test procedures for emergency repairs. The two took infrared video to see if damage within the shuttle's reinforced carbon panels could be detected.
Applying sealant with putty knife
The space shuttle brought damaged panels to see if astronauts could repair them in orbit using a substance called NOAX--a pre-ceramic polymer sealant containing carbon-silicon carbide powder. Their tools, a caulk gun and spatulas.
The weightless Discovery crew poses for a head-to-head photo shoot. From the bottom left are astronauts Stephanie Wilson; Steven Lindsey, commander; and Lisa Nowak. From the top left are astronauts Piers Sellers, Michael Fossum, and Mark Kelly.