NASA is pressing ahead with repair work on shuttle Discovery while engineers try to pin down the root cause of troublesome cracks in structural braces on its 15-story external tank.
The determination of root cause, meanwhile, will be key to gaining enough confidence to try to launch Discovery on its 39th and final flight during the last opportunity this year -- a short window that will stretch from Nov. 30 through Dec. 6..
NASA engineers and contractor technicians today are busy at Kennedy Space Center's launch pad 39A, replacing a leaky quick disconnect valve from seven-inch line that routes excess gaseous hydrogen from the external tank to a flare stack about 1,000 feet from the pad, where the explosive substance is safely burned off. A significant leak from the line prompted NASA to scrub a Nov. 5 launch attempt. Engineers found the valve and an internal seal were misaligned and that a leak path was opened up as a result.
Also in work: technicians are repairing four cracks found on the tank after the scrub. The cracks are on two "stringers" -- structural braces located on the middle of the tank in the area between its hydrogen and oxygen reservoirs. The cracked stringers are being replaced with doublers, which essentially strengthen the braces.
The discovery of cracks on the second stringer has prompted managers to call for extra inspections on the tank while engineers attempt to determine the root cause of the problem. Senior managers will meet Thursday to review inspection data and then a status briefing will be conducted next Monday to determine whether NASA will be able to try to launch Discovery during the upcoming window. If not, a string of Russian, European and Japanese cargo missions to the station, and inadequate solar conditions at the outpost in January, will conspire to push the launch back to late February.
One other repair operation is taking place at the pad: a circuit breaker panel in Discovery crew cabin is being replaced. A faulty breaker on the panel kept a back-up main engine controller from operating properly during the countdown to the Nov. 5 launch attempt. Engineers found trace contaminate on the faulty breaker.
ABOUT THE IMAGES: Click to enlarge the latest still images from live video feeds in the Launch Complex 39 area at Kennedy Space Center.
6 comments:
Dunno bout anybody else, me thinks I would be packing plenty of Xtra undies for this trip...
The longer they can delay it, the longer on payroll. Think about it.
Maybe those cracks occurred at the plant that manufactured the tanks?
Has NASA ruled that out?
They never stated how draining the ED caused the cracks to occur! How come this hasn't occurred during the past draining of the ET?
Bunch of incompetent fools delaying their inevitable layoffs by prolonging the last few launches. Let's hope it doesn't end up like the Challenger. Scrap metal & worthless apologies.
You know, it seems that there are always people that take aim at NASA. They are NOT delaying to prolong the program. They are just trying to ensure that we fly safely. When / if those jobs are gone, you will see it in your pockets as well. When those people move away from your area, your tax base will be gone, as well as other businesses that are dependent on the very people's salaries that help all of you... Best of luck on trying to survive... Oh, I guess you can always work at the beach as a surf board waxer!
Hey, 9:31 am post I am the 9:46 pm post. I feel what you are saying. That is why I said rollback, destack and replace with another ET. This is not the time to attempt a fix they have never done on the pad or at KSC.
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