Problem aborts space shuttle main engine test firing
BY JUSTIN RAY
Posted: June 23, 2000
The space agency has named an investigation team to determine what caused the engine to shut itself down five seconds into a planned 200-second firing at the Stennis Space Center in Mississippi.
Robert Sackheim, assistant director and chief engineer for propulsion at NASA's Marshall Space Flight Center, will lead the review.
The test last Friday evening was a qualification firing of the new high-pressure liquid hydrogen turbopump. During the hotfire, the engine was supposed to operate at hotter temperatures than normal, pushing the envelope of the powerplant's design to demonstrate its capability, NASA spokesman Ed Medal said.
"We were conducting the test to the upper design limit of the engine," he said.
But something went wrong and the engine's safety system halted the test.
Inspections have revealed turbine and combustion chamber damage inside the engine and erosion on a pre-burner injector faceplate, Medal said.
In order to create hotter temperatures, the engine was outfitted with a smaller main combustion chamber.
NASA is testing the new turbopump as part of the space shuttle upgrades effort to make the 20-year old stubby-winged spaceplanes safer and more reliable. The space agency plans to fly the pump for the first time during a launch in January.
As the defining part of future Block 2 engines, the new pump is stronger and its internal housing is manufactured using a casting process. The pump housing was not damaged in last week's incident.
Two earlier engine redesigns have occurred over the past five years, all to improve engine safety.
Medal said the incident is not expected to delay the next space shuttle mission, saying the engine that shut down was in a much different configuration than those currently in use.