At T-9 minutes and counting, space shuttle Discovery is moving toward an on-time liftoff at 4:50 p.m. EST. During the hold, a series of polls will be conducted to verify the readiness of managers and engineers at Kennedy Space Center and Mission Control in Houston to proceed with launch.

Discovery is embarking on its last mission. It will carry the Leonardo Permanent Multipurpose Module, or PMM, to the International Space Station. The PMM has been loaded with supplies, experiments, equipment and a humanoid robot assistant for the station. The Robotic astronaut is called Robonaut 2 and it will become the first robot of its kind to fly into and work in space.

During space shuttle Discovery’s final spaceflight, the STS-133 crew members will take important spare parts to the International Space Station along with the Express Logistics Carrier-4.

Steve Bowen replaced Tim Kopra as Mission Specialist 2 following a bicycle injury on Jan. 15 that prohibited Kopra from supporting the launch window. Bowen last flew on Atlantis in May 2010 as part of the STS-132 crew. Flying on the STS-133 mission will make Bowen the first astronaut ever to fly on consecutive missions.

Source: NASA release