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ATLANTIS’ O-RING SEALS `WORKED GREAT’

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The space shuttle Atlantis' two solid-fuel boosters, equipped with redesigned post-Challenger O-ring seals, appear to have "worked great" during launch Dec. 2, a top NASA manager said Friday.

Aviation Week & Space Technology magazine, meanwhile, reports in its Dec. 12 issue that Atlantis's astronauts launched a secret "Lacrosse" spy satellite the same day they blasted off and initially ran into problems getting the $500 million spacecraft's solar panels to open."The Lacrosse satellite's massive solar arrays initially failed to unfold when commanded to swing open after the spacecraft was deployed from the shuttle," the magazine said. "The deployment occurred during the fifth orbit, about seven hours after launch.

"Defense managers feared the mission might fail, but a second set of radio commands freed the solar arrays."

As for Atlantis's boosters, Royce Mitchell, manager of the shuttle booster project at the Marshall Space Flight Center in Huntsville, Ala., said by telephone that a preliminary examination of the big rockets indicates they performed as advertised during the 27th shuttle launch.

"They've been inside the motors and everything looks great," Mitchell said, adding that a complete assessment will not be available until the rockets are disassembled for a detailed inspection.

The Wall Street Journal reported Friday that hot gas made it past an insulation material in the nozzle joints of the rockets used by the shuttle Discovery during the first post-Challenger launch Sept. 29 and that more of the same was expected when engineers finished taking apart the rockets used by Atlantis.

But Mitchell, who was quoted in the Journal story, dismissed the issue when asked about it by United Press International.

"It's a non-problem," he said, clearly angry. "We don't even have it on our in-flight anomaly list to be addressed and closed prior to the next flight."

Each booster nozzle assembly is made up of five joints. After the joints are assembled, Mitchell said, a rubbery heat-resistant material is injected into small gaps where the joints are located.

"We backfill those joints . . . because there's a gap there," Mitchell said. "That gap is there for thermal growth and assembly tolerances. And so as a thermal filler, we . . . squirt RTV silicon down in there as kind of a thermal barrier.

"From time to time, we get gas past that backfill. We've never had O-ring distress and certainly not an O-ring leak or failure or anything. We saw it in our test program."