NASA Shuttle Atlantis STS-132 Mission

Once Atlantis returns to Earth, only two scheduled missions remain, both of them still angling to pin down their departure dates. Discovery is tentatively slated to lift off on Sept. 16 on an eight-day flight to the ISS that will deliver an Italian Multi-Purpose Logistics Module upgraded as a permanent supply compartment.

Endeavour, recently bumped to a tentative Nov. 27 launch date from late July, will deliver the Alpha Magnetic Spectrometer, an external observatory with 16 national sponsors for the study of cosmic rays and space particles.

For that final 10-day mission, Atlantis will be reprocessed and outfitted with an external fuel tank and solid rocket boosters to serve as a launch-on-need rescue mission for Endeavour’s six-man crew.

NASA has been discussing an as-yet-unscheduled Atlantis launch on a final supply mission to the station after Endeavour flies, with as few as four crew, who would wait out a Soyuz rescue on the station if their ship were crippled by launch debris or a malfunction.

Shannon characterises the prospect as remote, although Mike Suffredini, NASA’s space station program manager, says he would welcome a visit from Atlantis with a cargo of research equipment and spare parts for the station’s water recovery system in the summer of 2011.

Expectations have dimmed that a pair of yet-to-be-tested commercial cargo launch services will begin deliveries to the station next year.