Main Propulsion
Test Article  (MPTA-098)

Background

The Main Propulsion Test Article (MPTA-098) consisted of an Orbiter aft-fuselage, a trus arrangement which simulated the Orbiter mid-fuselage and a complete Space Shuttle Main Engine (SSME) thrust structure including all main propulsion system plumbing and electrical systems. The unit was shipped to the National Space Technology Laboratory (NSTL) on 06/24/77 where it was mated with the Main Propulsion Test Article External Tank (MPTA-ET) and used for static engine tests. The MPTA-ET is now located at the Marshall Space Flight Center (MSFC) Alabama Space and Rocket Center where it is mounted to the "Orbiter Simulator" Pathfinder while MPTA-098 is at the Stennis Space Center (SSC) in Mississippi (previously called the NSTL).

On 7/2/79, MPTA-098 suffered major structural damage due to a fractured fuel valve on engine 2002. Testing resumed two months later but a liquid oxygen high speed turbopump failed 9.7 seconds into a scheduled 510 second test. It wasn't until 12/17/79 that a complete static firing was accomplished that included 3 main engines running up to 100 percent of rated thrust for 554 seconds.

On 1/17/81, just three months prior to the scheduled STS-1 launch date, MPTA-098 successfully demonstrated a 625 second firing. The three flight rated engines from Columbia were removed, shipped to NSTL, and installed on MPTA-098 where they successfully completed a 520-second flight mission demonstration test. The engines were then shipped back to KSC and installed on Columbia where they successfully performed a 20-second Flight Readiness Firing (FRF) on 2/20/81. This cleared the way for the launch of STS-1 on 4/12/81.

Construction Milestones (MPTA-098)

Testing Milestones (MPTA-098)