WASHINGTON — The test failure of a rocket nozzle component likely will force a delay of six to 10 weeks--possibly until mid-August--in the first post-Challenger space shuttle mission, the National Aeronautics and Space Administration said Monday.
The space agency had planned to launch the shuttle Discovery on June 2. But a test last month of the redesigned shuttle booster rocket resulted in the breaking of an eight-foot-diameter "boot ring" inside the nozzle.
Meanwhile, the booster manufacturer said there were no other failures during the test.
"All of the rest of the nozzle, with the exception of the boot ring . . . looks super," said Rocky Raab, a spokesman at Morton Thiokol Inc.
The boot ring, two inches thick and seven inches wide, was being used for the first time in the test. The ring attaches a flexible boot that allows the rocket nozzle to swivel in flight.
'Not Going to Use' It
"At this point, we know we are not going to use the component," said Sara Keegan, a NASA spokeswoman. She said it was not certain whether a version of the ring that had withstood an earlier full-scale firing will be used instead.
Of the delay caused by the latest problem, Keegan said the "best guess is somewhere in the area of 6 to 10 weeks. That's our best assessment of what the problem is going to entail."
John Thomas, an official at NASA's Marshall Space Flight Center in Alabama, said through a spokesman that the delay will be held to the 6 to 10 week period if the earlier design of the boot ring is used and everything else remains on schedule.
Thomas was in charge of redesigning the shuttle booster rocket after the January, 1986, destruction of the Challenger and death of its crew of seven. He is part of the NASA team studying the new problem at the Morton Thiokol plant in Utah.
Raab said engineers picking apart the solid-fuel motor Monday also found that the rocket's case-to-nozzle joint worked as designed, preventing gases from escaping.
"They found one gas path through the adhesive as far as the (case-to-nozzle joint's) O-ring, but that's considered normal, expected," he said.
Failure of a rubber-like O-ring seal in one of Challenger's booster joints was blamed by a presidential commission for leaking super-hot gases that ignited the explosion that destroyed the spacecraft.
The defective nozzle has been taken off the rocket and into a Morton Thiokol building, but the actual disassembly will take a few days.
Morton Thiokol was to have shipped the aft sections of the booster rockets for the first flight by rail on Saturday, but the shipment was held up. David Drachlis, a NASA spokesman at Marshall, said that if everything goes well, the shipment might take place in mid to late February.
Five months is required to prepare a shuttle for flight after the booster rocket segments arrive at the Kennedy Space Center in Florida.
Later Launching Seen
Aviation Week and Space Technology magazine said in its Jan. 4 edition that the most optimistic launching date is September.
In another development, an internal report by NASA's safety experts concluded that the space agency still lacks the skilled engineers, clear guidelines and leadership to ensure the safety of manned spaceflight, the Atlanta Journal-Constitution reported in today's editions.
The agency is falling into a "safety second" mind-set despite heightened safety concerns after the worst accident in spaceflight history, according to the internal report prepared by a committee of safety experts.
NASA officials acknowledged the problems singled out by the committee but told the newspaper that they were working to correct them and said the report was not meant for public consumption.