CAPE CANAVERAL, Fla. -- Space shuttle Discovery, atop the mobile launcher platform, makes the slow 3.4-mile journey via the broad, two-track crawlerway to Launch Pad 39A at NASA's Kennedy Space Center in Florida. First motion out of the Vehicle Assembly Building (at right) was at 5:17 a.m. EST. Discovery is targeted to launch to the International Space Station Feb. 12. During Discovery's 14-day mission, the crew will install the S6 truss segment and its solar arrays to the starboard side of the station, completing the station's backbone, or truss, enabling a six-person crew to live there starting in May. Photo credit: NASA/Troy Cryder KSC-2009-1121

The Space Shuttle program was the United States government's manned launch vehicle program from 1981 to 2011, administered by NASA and officially beginning in 1972. The Space Shuttle system—composed of an orbiter launched with two reusable solid rocket boosters and a disposable external fuel tank— carried up to eight astronauts and up to 50,000 lb (23,000 kg) of payload into low Earth orbit (LEO). When its mission was complete, the orbiter would re-enter the Earth's atmosphere and lands as a glider. Although the concept had been explored since the late 1960s, the program formally commenced in 1972 and was the focus of NASA's manned operations after the final Apollo and Skylab flights in the mid-1970s. It started with the launch of the first shuttle Columbia on April 12, 1981, on STS-1. and finished with its last mission, STS-135 flown by Atlantis, in July 2011.

• STS-119: Readying Discovery for space - collectSPACE: Messages
• STS-119 Shuttle Report - Spaceflight Now
• STS-119 Discovery - Eureka - Daniel Marin Naukas