CAPE CANAVERAL, Fla. NASA contractor engineers have uncovered a shuttle engine turbopump problem, but the trouble isnt expected to delay the upcoming launch of Endeavour on a mission to the International Space Station.
Endeavour and four astronauts are scheduled to blast off Nov. 29 on a mission to ferry a new three-person crew to the station and then return to Earth with the outposts current tenants.
A flaw, however, recently was discovered during inspections on an engine turbopump flown on a July 1999 telescope-delivery mission aboard shuttle Columbia.
Specifically, engineers found a small crack in an internal vane that helps direct the flow of liquid oxygen through the pump, which is about the size of an automobile engine.
And while two of Endeavours three main engines feature identical pumps, NASA officials say the ship likely will be cleared for flight at the conclusion of an ongoing engineering analysis.
"Bottom line is that the engineers dont think its going to be an issue for launch," said Dom Amatore, a spokesman for NASAs Marshall Space Flight Center in Huntsville, Ala., the agency field center that manages shuttle propulsion system programs.
"But they wont know for sure until they are done with their investigation."
Made by Boeings Rocketdyne division, the pumps in question direct the flow of supercold liquid oxygen from a 15-story external tank through shuttle engines, all three of which release an amount of energy 23 times the output of the Hoover Dam.
Severe cracks within internal pump vanes potentially could create metal debris that could jam up the pump in a worst-case scenario, causing an engine shutdown or even an explosion in flight.
Also a possibility: A decrease in engine performance that could leave a shuttle in a lower-than-intended orbit.
Preliminary analysis shows that the small crack found within Columbias pump would not hamper engine performance or endanger a shuttle if the part flew again. Consequently, engineers expect that two Endeavour engines featuring identical pumps likely will be cleared for flight.
Endeavours third engine sports a newer, advanced liquid oxygen pump and is not suspect.
The ongoing engineering analysis, meanwhile, likely will be completed by the time shuttle program managers meet next week for a traditional flight readiness review.
Program managers at that time could either clear Endeavour for flight or order the shuttles two suspect engines to be replaced. In the latter case, the planned Nov. 29 launch likely would be delayed at least two weeks.
The Endeavour astronauts are to ferry Russian cosmonaut Yuri Onufrienko and two U.S. flight engineers Daniel Bursch and Carl Walz up to the station, where the trio will live and work until next May.
Current station skipper Frank Culbertson and his two Russian colleagues Vladimir Dezhurov and Mikhail Turin remain scheduled to return to Earth aboard Endeavour on Dec. 10.
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