The STS-118 crew waves to spectators as they head for the Astrovan.

The STS-118 crew waves to spectators as they head for the Astrovan. From left are Mission Specialists Alvin Drew, Barbara R. Morgan, Dave Williams and Rick Mastracchio, Pilot Charlie Hobaugh, Mission Specialist Tracy Caldwell and Commander Scott Kelly. The Astrovan will take them to Launch Pad 39A for final suit preparations before climbing into Space Shuttle Endeavour for launch at 6:36 p.m. EDT. The STS-118 mission is the 22nd shuttle flight to the International Space Station. It will continue space station construction by delivering a third starboard truss segment, S5, and other payloads such as the SPACEHAB module and the external stowage platform 3. The 11-day mission may be extended to as many as 14 depending on the test of the Station-to-Shuttle Power Transfer System that will allow the docked shuttle to draw electrical power from the station and extend its visits to the orbiting lab. NASA/Kim Shiflett