Space shuttle Endeavour's crew completed today's inspection of the shuttle's thermal protection system at 2:16 a.m. EDT. The crew began the inspection early. They used the 50-foot-long Orbiter Boom Sensor System to conduct a high fidelity, three-dimensional scan of areas of the shuttle that experience the highest heating during entry - 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. As a consequence, the risk of re-entering with undetected micrometeoroid debris is increased but deemed acceptable.
During the mission's fourth and final spacewalk on Friday, the boom will be left at the space station to extend the robotic reach. Mike Fincke and Greg Chamitoff will prepare it for its stay by replacing its grapple fixture with a power data grapple fixture to enable its use as the new International Space Station Boom Assembly. Once on station without power and in the extended exposure to the vacuum of space, the boom's imagery sensors will cease functioning.