Engineers install J-2X engine E10002 in the A-1 test stand at NASA's Stennis Space Center. The installation is in preparation for a new series of tests, where the engine will be gimbaled, or pivoted, during test firings.

Gimbal tests are an important part of the design process. When this upper stage engine is used in space, it will need to be able to move freely to steer NASA's Space Launch System, or SLS - an advanced heavy-lift launch vehicle that will provide an entirely new national capability for human exploration beyond Earth's orbit.

This is the first full engine to be installed in the A-1 test stand in almost a decade and the first time gimbal tests will be performed since testing on the space shuttle main engines.

A series of tests was completed on the E10002 engine in the A-2 test stand prior to its installation on the A-1 test stand at Stennis. Once this series of tests is complete, the engine will be removed, and preparations will be made to begin testing the RS-25 engine on the A-1 stand in 2014.

RS-25 engines from the Space shuttle inventory will power the core stage of SLS, while the J-2X engine will power the upper stage of the evolved launch vehicle. The SLS Program is managed at NASA's Marshall Space Flight Center. The J-2X engine is being built by Pratt and Whitney Rocketdyne.