Crew Switches To Back-Up Sensors For Heat-Shield Survey

A back-up sensor package is being pressed into service so the Atlantis astronauts can perform a streamlined inspection of vulnerable shuttle heat shield components.

The prime sensor package on the end of the shuttle's 50-foot boom inspection is not tilting properly because an electrical cable is blocking its way. The back-up sensor package must be used on the sun-lit side of Earth because it is equipped with digital camera that requires light to collect images. The television camera on the prime sensor package is equipped to operate on the light or dark sides of Earth.

NASA in the wake of the 2003 Columbia accident developed the 50-foot extension boom, which lathes on to the shuttle's equally lengthy robot arm. Sensor packages on the tip of the boom enable astronauts to inspect the 44 composite carbon panels that act as thermal armor for the shuttle's wings as well as the ship's nose cap and crew cabin.

The astronauts will be switching to a streamlined procedure that will skip the crew cabin inspections. Those areas presumably will be surveyed during a standard inspection done after shuttles depart the International Space Station. They also could be done while Atlantis is docked at the outpost, but that might eat up time during an already packed schedule of work planned during the shuttle's weeklong stay at the station.