Space Shuttle Discovery moved to Launch Pad 39A at Kennedy Space Center, where the huge spacecraft is poised to lift off at 7:32 a.m. ET Feb. 12.
A launch dress rehearsal, the three-day terminal countdown demonstration test, begins today.
STS-119 astronauts and ground crews will participate in the practice countdown. The test provides each shuttle crew with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training.
Discovery will launch on the 14-day mission to the International Space Station, where the shuttle crew of seven astronauts will install the S6 truss segment to the starboard, or right, side of the station and deploy its solar arrays. Four spacewalks will be conducted during the flight.
Lee Archambault will command the STS-119 mission. Tony Antonelli will be the pilot. Mission specialists are Joseph Acaba, Steve Swanson, Richard Arnold, John Phillips and Japan Aerospace Exploration Agency astronaut Koichi Wakata. Wakata will remain on the station as a resident crew member, replacing station Flight Engineer Sandra Magnus, who will return home on Discovery.
STS-119 is the 125th shuttle flight, the 36th flight for Discovery and the 28th flight to the station.
Under orders from outgoing President Bush, construction of the space station must be completed and the space shuttle fleet must stop flying by October next year, so that shuttle money can be used to develop the shuttle replacement, the next-generation Orion-Ares spacecraft system.
The first Orion-Ares manned flight is set for March 2015.
Meanwhile, NASA will pay Russia to fly U.S. astronauts to orbit on Soyuz spacecraft. Or, private space transportation companies may develop crewed transport vehicles that could fill the half-decade gap.