This photograph shows an inside view of a liquid hydrogen tank for the Space Shuttle external tank (ET) Main Propulsion Test Article (MPTA). The ET provides liquid hydrogen and liquid oxygen to the Shuttle's three main engines during the first 8.5 minutes of flight. At 154-feet long and more than 27-feet in diameter, the ET is the largest component of the Space Shuttle, the structural backbone of the entire Shuttle system, and is the only part of the vehicle that is not reusable. The ET is manufactured at the Michoud Assembly Facility near New Orleans, Louisiana, by the Martin Marietta Corporation under management of the Marshall Space Flight Center.

The first Space Shuttle External Tank, the Main Propulsion Test Article (MPTA), rolls off the assembly line September 9, 1977 at the Michoud Assembly Facility in New Orleans. The MPTA was then transported to the National Space Technology Laboratories in southern Mississippi where it was used in the first static firing of the three main engines. Marshall Space Flight Center had management responsibility for Space Shuttle propulsion elements, including the External Tank. Martin Marietta was the prime contractor who designed and assembled the tanks at Michoud.

A structural steel section is lifted into place atop the B-2 Test Stand at NASA’s Stennis Space Center as part of modification work to prepare for testing the core stage of NASA’s new Space Launch System. The section is part of the Main Propulsion Test Article (MPTA) framework, which will support the SLS core stage for testing. The existing framework was installed on the stand in the late 1970s to test the shuttle MPTA. However, that framework had to be repositioned and modified to accommodate the larger SLS stage. About 1 million pounds of structural steel has been added, extending the framework about 100 feet higher and providing a new look to the Stennis skyline. Stennis will test the actual flight core stage for the first uncrewed SLS mission, Exploration Mission-1.