NASA prepares to lift shuttle tank

NASA contractor technicians are preparing to place a shuttle external tank on a transporter so work associated with the change-out of suspect fuel-depletion sensors can be completed.

Operating a 325-ton crane, technicians on Tuesday will lift the 15-story tank from a checkout cell in the Kennedy Space Center Vehicle Assembly Building and then place it horizontally on a transporter.

The yellow transporter is in the transfer aisle of the 525-foot-tall building. The move will enable contractor technicians to reapply foam insulation around a manhole cover on the aft dome of the tank.

The foam was removed late last month so technicians could enter the tank through the manhole and replace four liquid hydrogen Engine Cut Off, or ECO, sensors. One of the critical sensors generated unexpected readings during an electrical test, prompting managers to order the change-out work.

The March 14 decision forced NASA to postpone its second post-Columbia shuttle test flight from May to July.

The crane operation is expected to take a little more than eight hours.

NASA and contractor managers are scheduled to meet April 21 to determine whether to proceed with the mating of the tank to a pair of solid rocket boosters already stacked on a mobile launcher platform in the assembly building.

The mating operation is tentatively scheduled for April 24.

The orbiter Discovery still is scheduled to move May 12 from its processing hangar to the assembly building, where it will be mated with the tank and its attached boosters.

The fully assembled shuttle is scheduled to roll out to the launch pad on May 19. Launch is scheduled during a window that will extend from July 1 through July 19.