Six NASA astronauts will use the next-to-last mission of the space shuttle Atlantis to begin preparing the International Space Station for the day when there will be no shuttles to keep the station supplied.

Liftoff of Atlantis on the third utilization and logistics flight (STS-129/ULF-3) is set for as early as 2:28 p.m. EST Nov. 16, kicking off an 11-day mission. The flight will see three spacewalks to prepare a place for the final U.S. pressurized station module, and bring ISS Expedition 20 and 21 flight engineer Nicole Stott home, in the last station-crew rotation on a shuttle. But the main event will be elaborate robotics work to attach outsize spare parts to the station truss.

“This flight is all about spares,” says Brian Smith, the mission’s lead station flight director. “Basically, we’re getting them up there while we still can.”

Packed in the orbiter’s commodious payload bay will be two Express Logistics Carriers (ELCs), which will be pulled out of the orbiter and installed on the station truss with the Canadian-built shuttle and station robotic arms.

Bolted to the ELCs will be 27,250 lb. of spare parts that are too big and massive to fly in any of the vehicles that will be left when the shuttle retires—probably in the first half of 2011. They include two 600-lb. control moment gyro assemblies; a 415-lb. latching end effector for the station’s robotics; and two nitrogen tank assemblies, weighing 550 lb. each, that pressurize the ammonia tank assemblies for the station cooling system.

Atlantis is also delivering one of the 1,702-lb. ammonia tank assemblies. Other hardware to be delivered includes two 780-lb. cooling-system pump module assemblies; a 1,240-lb. high-pressure gas tank filled with 220 lb. of gaseous oxygen contained at 2,450 psi., and a new Materials International Space Station Experiment (Misse-7) for future space-exposure experiments.

The mission will include the normal post-launch inspection with the orbiter’s robotic arm and 50-ft. extension boom, and the back-flip rendezvous pitch maneuver, both to ensure that the thermal protection system escaped serious damage on ascent.

Rendezvous and docking will occur nominally on Flight Day 3. The ELCs are to be moved on Flight Days 3 and 6, and the spacewalks are scheduled on Flight Days 4, 6 and 8.

Astronauts Randy Bresnik, Mike Foreman and Robert Satcher will pair off for the three extravehicular activities (EVAs), which will include installing an antenna assembly, lubricating robotics grippers and setting up cargo attachment platforms for future missions. They will also work with their colleagues inside the station to prepare the way for the Tranquility pressurized node, which is scheduled to be delivered by the shuttle Endeavour next February.

After some off-duty time on Flight Day 9, Atlantis is scheduled to undock on Flight Day 10 and perform a flyaround to document the station exterior. After preparing the orbiter cabin on Flight Day 11, they are set to return to KSC on the morning of Flight Day 12—Nov. 27 on a nominal mission time line.