Auxiliary power unit functional testing is also in progress. Columbia is jacked and leveled in Vehicle Assembly Building high bay 2 undergoing system observation during a temporary storage period. Columbia will remain in the Vehicle Assembly Building until mid-April, when Shuttle Discovery rolls out of Orbiter Processing Facility bay 1. Installation of Endeavour's three auxiliary power units is complete. No. 8 is also complete.
Preparations are in work to remove the left orbital maneuvering engine next week.
Checks on Atlantis' main propulsion system liquid oxygen and liquid hydrogen valves are complete. Orbital maneuvering and reaction control systems are undergoing drain line modifications and helium system leak checks are ongoing. The system will reply with a confirmation via e-mail of each subscription.