NASA gave American Tank and Vessel Inc. a contract worth up to $45 million to install a test cell diffuser and systems in the A-3 test stand at Stennis Space Center. Mioss.

American Tank, of Mobile, Ala., received a five-year, indefinite delivery, indefinite quantity contract.

The A-3 test stand is being built at Stennis to test the J-2X engine for the Constellation Program developing next-generation spacecraft systems to send astronauts to the International Space Station, the moon, Mars and beyond.

The J-2X will power the upper stage of the Ares I crew exploration vehicle and the Earth departure stage of the Ares V cargo launch vehicle.

The A-3 test stand will allow engineers to analyze J-2X operating parameters by simulating conditions at altitudes up to 100,000 feet. For these simulations, the test stand will generate approximately 4,620 pounds per second of steam and use it to reduce the engine test cell pressure.

Construction began on the A-3 test stand in summer 2007, with the first test scheduled for 2012. The structure is the first large test stand to be built since the south Mississippi site was established in the 1960s.