NASA looking at blanket and computer issue
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: February 9, 2008
Engineers are assessing what, if anything, might need to be done about a small section of an insulation blanket on the shuttle Atlantis' right side orbital maneuvering system rocket pod that apparently pulled away from a seam during launch. Close-up photography of the rocket pod shows one corner of the blanket pulled up slightly, similar to a problem that cropped up on Atlantis during an August mission.
Lead Flight Director Mike Sarafin described the pulled-up corner as a "small tear" along a seam between adjacent blankets, adding "it's probably not that big of an issue, but we're off looking at it."
The insulation blankets on the OMS pods experience temperatures between 700 and 1,000 degrees Fahrenheit during the 15 minutes or so of peak heating during re-entry. Sarafin said he did not yet know the dimensions of the blanket corner in question, but the protruding triangular area spotted on the right-side rocket pod during Atlantis' August flight measured 4 inches by 6 inches.
In that case, a spacewalking astronaut pushed the flap back into place and secured it with surgical staples. Three spacewalks are planned during Atlantis' current mission and the same staple gun is on board if needed. But engineers have not yet determined what, if anything, needs to be done.
"We have some work to figure out if we need to gather some additional inspection imagery on that," Sarafin sad.
The only other technical issue of any significance as of this writing is troubleshooting to verify the health of general purpose computer No. 3, one of five machines that control all aspects of shuttle operation.
GPC-3 failed to properly transition from "standby" to "run" when the astronauts powered up the full redundant set as part of their normal rendezvous procedures. Engineers believe the computer is healthy, Sarafin said, but troubleshooting was deferred until after docking.
The incident occurred "when we brought it up out of a powered-down config earlier today," Sarafin said. "It had what we call a common set fail. Basically, when you bring up the multiple computers they all start talking to each other and that computer started talking to the other computers to make sure it was in synchronization and then it stopped for some reason. We're off investigating that."
The shuttle is equipped with four GPCs that run identical software and a fifth, backup computer that runs software from a different vendor to protect against the possibility of a bug or other problem that could disable the redundant set. At one point, NASA carried a spare GPC on board. While that is no longer the case, Sarafin said the failure of a single GPC likely would have no major impact on the mission.