[STS-135] External Tank Scanned and Engine Valve Work

On June 20, technicians continued taking Computed Radiography (CR) X-ray scans of 50 support beams, called stringers, on space shuttle Atlantis' external fuel tank.

Technicians also are replacing the main fuel valve in Atlantis' space shuttle main engine No. 3, which apparently developed a small liquid hydrogen leak during the tanking test. The work is expected to take about a week, which still would support Atlantis' targeted July 8 launch date for its STS-135 mission
to the International Space Station. The 12-day flight is the last mission
of the Space Shuttle Program.