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. <br /><br />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 <br />to the International Space Station. The 12-day flight is the last mission <br />of the Space Shuttle Program.
