Alliant Techsystems has completed the second of two ground tests of a full-scale attitude control motor (ACM) for the launch abort system (LAS) of NASA's Orion crew exploration vehicle.

The second test was conducted on March 17, and evaluated environment extremes and ignition system robustness in addition to confirming the motor performance. The test was conducted at ATK's facility in Elkton, Maryland, where the first successful test was conducted on December 15, 2009.

Lockheed Martin, the prime contractor to NASA for Orion, leads the project team developing the nation's next-generation space flight vehicle to carry out missions to destinations throughout our solar system.

Orion's launch abort system is critical to the human rating of any similarly designed spacecraft and is essential for crew safety which is fundamental to successful human space exploration in the future.

This test of the control motor validates the readiness for NASA's upcoming pad abort 1 (PA-1) flight test that will be conducted at White Sands Missile Range (WSMR), New Mexico. The PA-1 ACM was delivered to WSMR in February. PA-1 is the first LAS flight test for NASA's Orion crew exploration vehicle.

"The success of this test, coupled with the success of the first test last December, demonstrates again that crew safety is an overriding priority in the design of the crew vehicles to be used in future human exploration missions.

We are now ready for the next major milestone, a flight demonstration," said Bart Olson, interim President, ATK Mission Systems.

ATK's attitude control motor provides steering for the Orion launch abort system, which is designed to safely lift and steer the Orion crew module away from the launch vehicle in the event of an emergency.

This was the seventh in a series of ground tests of Orion's attitude control motor system, validating that the thruster system performs as designed.

ATK's attitude control motor consists of a solid propellant gas generator, with eight proportional valves equally spaced around the circumference of the three-foot diameter motor.

In combination, the valves can exert up to 7,000 pounds of steering force to the vehicle in any direction upon command from the crew module. The valves are controlled by a redundant power and control system.

ATK is under contract to Lockheed Martin to develop the attitude control motor and provide motors for Orion's development test flights and human-rated flights. ATK is also responsible for the main launch abort motor, successfully test-fired November 2008, and the Ares I first stage, which was successfully test-fired in September 2009.

Orion Launch Abort System
The Orion launch abort system (LAS) activates within milliseconds in the event of an emergency on the launch pad or during initial ascent.

The LAS consists of three motors: the abort motor that fires nearly 500,000 pounds of thrust to pull the crew module up and away from the launch vehicle; the attitude control motor that exerts up to 7,000 pounds of steering force to reorient the vehicle's position; and the jettison motor that separates the crew module from the launch abort system so that parachutes can be deployed for a safe landing.

The jettison motor is the only motor that will be activated on all nominal missions to separate the spacecraft from the launch abort system assembly shortly after second stage activation.

ATK is providing the abort and attitude control motors and Aerojet is providing the jettison motor. All three motors have been integrated into the LAS assembly by a Lockheed Martin-led team at White Sands Missile Range in preparation for the Pad Abort 1 test this spring.