Shuttle tank headed back to factory

The last of three external tanks in storage at Kennedy Space Center at the time of the February 2003 Columbia accident was loaded aboard a barge today for a trip back to its New Orleans factory, where it will undergo safety modifications.

Mounted atop a yellow transporter, the tank -- designated ET-117 -- rolled out of the KSC Vehicle Assembly Building and onto a covered barge at the Launch Complex 39 Turn Basin.

Still evident on the tank: Two Protuberance Air Load ramps. The so-called PAL ramps are thick slabs of foam insulation designed to serve as windshields for pressurization lines and electrical cabling on the outside of the tank.

A PAL ramp on the tank that flew on NASA's first post-Columbia flight last July shed a one-pound chunk of foam debris that nearly struck Discovery's right wing. To prevent a recurrence, NASA has removed both PAL ramps from the tank that will fly with Discovery during a planned July 1 launch.

ET-117 also is still equipped with a large wedge of foam insulation known as the Bipod Ramp. The Bipod Ramp was designed to prevent ice build-up on metal struts that connect the nose of the shuttle orbiter with the tank. A 1.67-pound piece of foam debris from Columbia's Bipod Ramp caused the severe wing damage that led to the loss of that shuttle and its seven-member astronaut crew.

The barge is scheduled to depart Port Canaveral Tuesday for a five-day trip to Michoud Assembly Facility. The tank will be retrofitted with all post-Columbia safety modifications and then shipped back to KSC for use on a future International Space Station assembly mission.

Click to enlarge the image taken by NASA photographer Jack Pfaller.