NASA Tests Orion Launch Abort System (LAS) Attitude Control Motor (ACM)
This is a solid rocket motor. It weighs 1700 pound. It has one charge and one combustion chamber with eight valves and eight nozzles. Once ignited it burns until it is exhausted. It is used to control the attitude, or orientation, of the Orion spacecraft. In normal operation it is used to orient the spacecraft in preparation for re-entry. It would also be used in case of emergency during launch when the spacecraft is separated from the booster.
Update August 2015. Replaced missing video.