As smoke billows across Launch Pad 39A, Space Shuttle Endeavour climbs into the sky on mission STS-118, the 22nd shuttle flight to the International Space Station. The mission 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 a docked shuttle to draw electrical power from the station and extend its visits to the orbiting lab.