In this image provided by NASA the afternoon sun creates shadows on space shuttle Endeavour's external fuel tank as workers remove the seal from the Ground Umbilical Carrier Plate on the tank Wednesday June 24, 2009. A hydrogen leak at the location during tanking for the STS-127 mission caused the launch attempts to be scrubbed on June 13 and June 17. NASA plans a fueling test Wednesday July 1, 2009 of shuttle ahead of July 11 launch attempt. AP Photo logo AP Photo 5 months ago

In this image provided by NASA the afternoon sun creates shadows on space shuttle Endeavour's external fuel tank as workers remove the seal from the Ground Umbilical Carrier Plate on the tank Wednesday June 24, 2009. A hydrogen leak at the location during tanking for the STS-127 mission caused the launch attempts to be scrubbed on June 13 and June 17. NASA plans a fueling test Wednesday July 1, 2009 of shuttle ahead of July 11 launch attempt.