Discovery launch depends on external tank analysis

Discovery’s final flight will launch no earlier than Dec. 17 as NASA continues to investigate what caused cracks in metal brackets on the shuttle’s external tank earlier this month.

The cracks have been repaired, but engineers are still searching for the root cause behind the problem and studying the potential risk if more cracks occurred during flight.

“We have to understand what our exposure is to that problem recurring somewhere else on this tank,” John Shannon, the shuttle program manager, said today. “We want to make sure that we fully understand the problem before we commit to go fly.”

Shannon on Wednesday ruled out the possibility of a launch in the next available window, between Dec. 3 and Dec. 7.

The next window officially runs from Dec. 17 to Dec. 20, dates that would make Discovery the second shuttle to fly over the Christmas holiday. But other dates before the end of the year could be considered before a potential delay to February.

“We’ll fly Discovery when we’re fully confident in the ability of the tank to support the mission,” Shannon said.