spacetoday.net: External tank cleared for shuttle launch

Posted: Thu, Jun 8, 2006, 7:42 AM ET (1142 GMT)
STS-121: rollout (NASA/KSC)

Shuttle managers officially declared the space shuttle's external tank ready for launch after a final evaluation of test data about changes to its design. The tank design had undergone wind tunnel and other tests after NASA decided to remove a troublesome ramp that was prone to shedding foam during flight. The protuberance air load (PAL) ramp was designed to shield pressurization lines and cable trays on the tank from aerodynamic stresses during flight, but wind tunnel tests showed that the lines and cables would withstand those stresses without the ramp. The decision brings the shuttle a step closer to a July 1 launch, although the launch could slip a day to ensure better lighting conditions for photography of the tank after it separates from the shuttle orbiter. A firm launch date will be announced on June 17, at the conclusion of a flight readiness review.