Endeavour's crew Thursday performed a "late" inspection of the shuttle's thermal protection system earlier than normal given the activities planned for their mission's fourth spacewalk.

The STS-134 and Expedition 28 astronauts woke at 6:56 p.m. CDT on Wednesday to the song "Countdown" by the Canadian band Rush played for mission specialist Mike Fincke.

"Rush was really inspired by the launch of STS-1," said Fincke, "so they included that in their music. It was really inspirational for them, for their whole album. But what it is really cool about it is that the space shuttle program has really inspired everybody across the planet for such a long time. And so this song was a tribute to the space shuttle program."

Most of the crew day focused on the late inspection of the space shuttle, which was completed at 1:16 a.m.

They used the 50-foot-long orbiter boom sensor system to conduct a high fidelity, three-dimensional scan of the surfaces that will see the highest heating during reentry - the wing leading edges and nose cap. Managers and engineers in Mission Control will review the data to validate the heat shield's integrity and assure it has suffered no significant micrometeoroid and orbital debris damage.

The late inspection occurred earlier in the mission than normal, prior to undocking.

During the mission's fourth and final spacewalk on Friday, the boom will be left at the space station to extend its robotic reach. Once on station without power and in the extended exposure to the vacuum of space, the boom's imagery sensors will cease functioning.

The crew will spend time today preparing for the spacewalk. Fincke and mission specialist Greg Chamitoff, who will conduct the spacewalk, will be joined by mission specialist Andrew Feustel to gather tools, configure the suits and prepare the airlock.

On Wednesday evening, STS-134 commander Mark Kelly participated in media interviews with Tucson, Ariz., television stations. At 4:40 a.m., he and his crewmates will take part in an international news conference.

The nine members of the joint space shuttle Endeavour and International Space Station crews met in the Japanese Kibo laboratory early Thursday morning to answer questions from media gathered at NASA's centers and at the European Space Agency.