Main Propulsion Test Article (MPTA-098)

      Background

        The Main Propulsion Test Article (MPTA-098) consisted of an Orbiter aft-fuselage, a truss 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)

      07/26/72 Contract Award
      07/17/74 Start of long lead fabrication
      06/24/75 Start structural assembly of aft-fuselage
      01/23/76 Truss on dock at Rockwell Downey
      03/17/76 Complete premate at Downey and delivered to Palmdale
      05/03/76 Complete proof load test setup at Palmdale
      06/29/76 Move truss assembly from Palmdale Building 294 to 295
      07/08/76 MPTA-098 on dock at Downey
      07/12/76 Start of Final Assembly
      07/24/76 Complete MPTA-098 proof load test
      05/27/77 Completed Final Assembly, Transport to Seal Beach
      06/03/77 Transport from Seal Beach to NSTL
      06/24/77 Arrival at NSTL for static firing
      09/10/77 Arrival of MPTA-ET at NSTL

      Testing Milestones (MPTA-098)

      04/21/78 1st static firing (2.5 sec)
      05/19/78 2nd static firing (15 sec)
      06/15/78 3rd static firing (50 sec)
      07/07/78 4th static firing (100 sec)
      05/04/79 5th static firing flight nozzles (1.5 sec)
      06/12/79 5th static firing flight nozzles (54 sec)
      10/24/79 6th static firing flight nozzles (scrubbed)
      11/04/79 6th static firing flight nozzles (10 sec cutoff)
      12/17/79 6th static firing non-flight (554 sec)
      02/28/80 7th static firing non-flight (555 sec)
      03/28/80 8th static firing non-flight (539 sec)
      04/16/80 9th static firing non-flight (4.6 sec cutoff)
      05/30/80 9th static firing non-flight (565 sec cutoff)
      07/12/80 10th static firing flight nozzels (105 sec shutdown)
      11/03/80 11th static firing flight nozzels (20 sec shutdown)
      12/04/80 11th static firing non-flight (591 sec)
      01/17/81 12th static firing flight nozzels (625 sec)

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      Last Updated Wed Nov 10 11:14:52 EDT 1993
      Jim Dumoulin (Redacted)