Space Shuttle Atlantis External Tank Draining, No New Issues Seen

The Final Inspection Team, or ice team, has completed its walkdown of Launch Pad 39A at NASA’s Kennedy Space Center in Florida following this afternoon’s tanking test. Preliminary reports indicate no issues.

Teams currently are draining about 535,000 gallons of liquid hydrogen and liquid oxygen from space shuttle Atlantis’ external fuel tank. Starting Saturday, technicians will take hi-tech x-ray scans of the tank’s support beams, called stringers, on the shuttle-facing side of the tank. Earlier this year, managers directed teams to make the same stringer reinforcement modifications to Atlantis’ tank, ET-138, as they had after small cracks in the support beams of shuttle Discovery’s STS-133 mission external tank were discovered. ET-138 is a similar tank to the one that used for the STS-133 mission.

Managers scheduled a tanking test to help verify there are no issues. During the tanking test, the main fuel valve for Atlantis’ No. 3 space shuttle main engine recorded temperatures below normal levels, indicating a possible liquid hydrogen leak. Teams isolated the engine and continued to fuel Atlantis with no issues. Temperatures returned to normal readings. Once technicians are able to gain access to the engine after the area is cleared from tanking test operations Thursday, engineers will evaluate any necessary work on the fuel valve. Even if the valve needs to be replaced, managers expect that work could be done at the launch pad and still support Atlantis’ July 8 target date.