Tuesday, August 18, 2009

Live At KSC: NASA Holds Shuttle Readiness Review

LIVE IMAGES: The images above are from live video feeds in the Launch Complex 39 area at Kennedy Space Center. They will automatically refresh to the most up-to-the-minute image every 30 seconds.

A decision on whether to press ahead with the planned launch next week of Discovery or roll the shuttle back to its assembly building for repairs will be made at a flight readiness review that started this morning at Kennedy Space Center.

NASA engineers and contractor technicians at the same time are recovering from a cable swap-out that stalled other routine prelaunch work to the point a one-day slip in the targeted Aug. 24 launch is a possibility.

Discovery and seven astronauts are tentatively scheduled to blast off from Launch Complex 39A at 1:58 a.m. next Monday. The seven-member crew is due to arrive at KSC on Wednesday evening and launch countdown is slated to begin at 11 p.m. Thursday.

A firm launch date is expected to be set at the end of the flight readiness review, which began at 8 a.m. and could stretch into Wednesday. Bill Gerstenmaier, NASA's Associate Administrator for Space Operations, told managers and engineers that he didn't want to limit a thorough discussion of external tank foam issues that could prompt a shuttle rollback from the pad to the Vehicle Assembly Building.

One of 34 metal brackets that secures pressurization lines and electrically cabling to the outside of the external tank lost significant amounts of foam insulation during the past two shuttle missions and three since October 2007.

Thin strips of foam also peeled away from the central ribbed area of Endeavour's external tank during its launch on July 15.

At a program-level review last week, about 25 percent of the NASA and contractor shuttle engineering community thought the shuttle should be rolled back for repairs.

Extra tests and inspections were performed over the weekend in an effort to clear both issues. Managers will be briefed on the latest data at the review.

Out at pad 39A, technicians replaced a faulty cable associated with a line that vents gaseous hydrogen from the shuttle's external tank during fuel-loading operations. The cable swap stalled efforts to rig up small explosive devices that are used to separate the shuttle from its mobile launcher platform and ground support equipment. A target launch date slip to Aug. 25 is possible as a result.


Anonymous said...

on the first couple shuttle missions didn't they spray paint the external tank white and didn't that help hold on the foam? why not spray some of the areas that it is falling off white again?

Anonymous said...

The added weight of the paint is a liability with regards to the foam. They have also learned that the solvents in the paint degrade the foam cell structure and could cause accelerated delamination of the foam from the substrate.
The adheasion tests that have been performed will most likely spell out the fate of the foam, the scans can "see" to the interface of the foam to primer and determine if a proper cross link has occured.

Anonymous said...

"on the first couple shuttle missions didn't they spray paint the external tank white and didn't that help hold on the foam? why not spray some of the areas that it is falling off white again?"
Did not work at all. Plus it would add weight, something the shuttle and launch vehicles in general is very sensitive to.

One pound of weight added to the vehicle means one pound less available for useful payload. And some missions are very tight on performance of the vehicle.

Anonymous said...

I got this from apacheman on Twitter: "The sign coming to the pad now says launch is the 25th at 01:35 am."