The most-used vehicle in NASA's space shuttle fleet is about to lift off on its final scheduled voyage. The STS-133 mission to the International Space Station (ISS) on space shuttle Discovery is now scheduled to begin November 5 with a 3:04 P.M. (Eastern Daylight Time) launch from Kennedy Space Center in Florida.* It is the last mission on the calendar for Discovery before the shuttle program is phased out in 2011.

The 11-day mission will deliver to the ISS two major pieces of hardware: the Italian-built Permanent Multipurpose Module, which will be attached to the U.S. Unity node to provide storage and work space; and an Express Logistics Carrier, an external platform that can store spare parts on the station. Discovery will also bring to the ISS a humanoid robot, developed in partnership with General Motors, called Robonaut 2. The robot's purpose, according to NASA press materials, is to test how such robots work in space with the hope of eventually delegating some maintenance or spacewalking tasks to Robonaut's more advanced successors.

With 38 missions completed since its inaugural trip in 1984, Discovery has flown more times than any other orbiter in the shuttle fleet. The next shuttle mission, targeted for February, would send space shuttle Endeavour to the ISS. A NASA authorization bill that passed Congress in September paved the way for one more and probably final shuttle flight, also to the ISS, using space shuttle Atlantis in mid-2011. (That mission, STS-135, awaits appropriations legislation and is not yet on NASA's public launch calendar.)

Discovery had been slated to lift off November 1, but the launch date was postponed first due to gas leaks in one of the shuttle's Orbital Maneuvering System engine pods, then due to an electrical glitch in a controller for one of the shuttle's main engines, and most recently due to bad weather. As of the morning of November 4, NASA was forecasting only a 60 percent chance of permissible weather for the November 5 launch.

The STS-133 crew comprises commander Steven Lindsey, pilot Eric Boe, and mission specialists Timothy Kopra, Michael Barratt, Nicole Stott and Alvin Drew. All six are NASA astronauts with previous spaceflight experience.

*UPDATE (11/10/10): The STS-133 launch is now scheduled for no sooner than November 30.

Photo of Robonaut 2: NASA