Atlantis Set to Launch

Space Shuttle Atlantis (STS-129) is scheduled to launch from the Kennedy Space Center in Florida later this afternoon. The 11 day mission to the International Space Station will deal primarily with the task of delivering spare parts that could be used to repair the ISS in the future. NASA plans to retire its shuttle fleet next year, and since the shuttle is the only vehicle capable to delivering large pieces of equipment to the space station, making sure that the ISS is well stocked with spares in the event of breakdown has become one of NASA's top priorities. As far as what sorts of spare parts are going up, NASA has this to say:

The spares are going up on two platforms – called external logistics carriers, or ELCs – to be attached on either side of the station’s truss, in hopes that wherever a failure happens, the necessary spare won’t be too far away. The ELCs carried up on STS-129 will be chocked full with two pump modules, two control moment gyroscopes, two nitrogen tank assemblies, an ammonia tank assembly, a high-pressure gas tank, a latching end effector for the station’s robotic arm and a trailing umbilical system reel assembly for the railroad cart that allows the arm to move along the station’s truss system. There’s also a power control unit, a plasma container unit, a cargo transportation container and a battery charge/discharge unit. In all, that’s 27,250 pounds worth of spares to keep the station going long after the shuttles retire.

Atlantis will carry a crew of 6 astronauts and will dock with the ISS on flight day 3 (Wednesday). Astronaut Nicole Stott, currently a member of the ISS crew, will be returning to Earth aboard Atlantis after spending over two months in space.