Main Propulsion Test Article (MPTA-098)
The Main Propulsion Test Article (MPTA-098) (German: main propulsion test article ) was developed by Rockwell International American US as a test bench for the final drive and fuel supply systems for the space shuttle built program.
description
The MPTA, which was never intended for actual space flight, consisted of the inner structure of a rear fuselage of the space shuttle orbiter, a truss structure that simulated the basic structure and shape of an orbiter fuselage, and a complete space shuttle main engine (SSMEs ). including all main propulsion system lines and associated electrical systems.
Later the very different STA (Structural Test Article) was converted into an airworthy orbiter, renamed again to OV-099 and christened Challenger . Rockwell and NASA therefore retrospectively referred to the MPTA as MPTA-098, although it was never baptized with a name.
history
On June 24, 1977, Rockwell International shipped MPTA-098 to the National Stet Technology Laboratory (NSTL) in Hancock County, Mississippi, where it was connected to the External Tank Main Propulsion Test item ( MPTA-ET ), the mounted in the starting position and used for static engine tests.
On July 2, 1979, MPTA-098 suffered significant structural damage due to a broken fuel valve on Space Shuttle Main Engine number 2002. Hydrogen escaped through the defective valve into the closed rear compartment, so that the overpressure caused severe damage to the structure.
After extensive repairs, testing resumed in September, but on November 4th a high pressure oxidizer [turbo pump] failed at 9.7 seconds in a scheduled 510 second test. Finally, on December 17, 1979, a full static ignition was performed that included all three space shuttle main engines at up to 100 percent of rated thrust for 554 seconds and exceeded the predicted maximum time the SSMEs would spend during an operational shuttle launch .
Flight certification
The Preliminary Flight Certification (PFC) program that would pave the way for the SSMEs aboard manned spacecraft began in early 1980. A number of setbacks, including the high pressure turbo pump overheating at 4.6 seconds into a 544 seconds Test on April 16, 1980, a hydrogen preburner burnout in a 581 second test after 105 seconds in July, and a nozzle structural failure in a test in November 1980 after 20 seconds, slowed progress dramatically. These errors resulted in a number of changes to the SSMEs and their associated systems.
Due to the number of changes in the SSME design since the SSME installation on the Columbia space shuttle, the three SSMEs (numbers 2005, 2006 and 2007) of the Columbia were expanded and successfully tested in the MPTA-098. The engines were then sent back to the Kennedy Space Center and reinstalled in Columbia.
On January 17, 1981, less than three months ahead of the scheduled STS-1 launch date, MPTA-098 successfully demonstrated a 625 second ignition with simulated abort profiles that completed the final PFC test and made the SSME design fully for flight certified. This paved the way for the STS-1 launch on April 12, 1981.
Shuttle-C
From 1981 to 1988 the MPTA-098 and MPTA-ET remained "in-situ" on the NSTL test bench, unused. In late 1988 Essex Corporation used the MPTA's thrust structure as the basis for a technical development model for the proposed Shuttle-C launcher . The model was used by NASA and Boeing at the Kennedy Space Center and the Marshall Space Flight Center to carry out checks and manufacturing studies. The Shuttle-C program was subsequently canceled by the United States Congress in 1990 , and the model was disassembled.
Shuttle Enterprise Upgrade
It was initially considered to convert the non-spaceflight Enterprise into a full-fledged space shuttle using the MPTA-098 . This idea was discarded and instead the STA (Structural Test Article) expanded into the Space Shuttle Challenger OV-099. After the Challenger disaster, this idea was considered again, but preference was given to building the new space shuttle Endeavor OV-105 using existing spare parts. After the Columbia disaster, the idea was taken up again, but had no chance as the end of the shuttle program was already in sight.
Current status
The main propulsion test item, without a framework, is on display at the US Space & Rocket Center, NASA Marshall Space Flight Center visitor information center in Huntsville , Alabama , next to the MPTA-ET, under the refurbished Space Shuttle Mockup Pathfinder orbiter simulator .
literature
- Jenkins, Dennis R .: Space Shuttle: The History of the National Space Transportation System: The First 100 Missions . World Print, Hong Kong 2002, ISBN 0-9633974-5-1 .
- Bart Hendrickx, Bert Vis: Energiya-Buran: The Soviet Space Shuttle . 2007, ISBN 0-387-69848-5 .