Wednesday, December 16, 2009

Orion Launch Abort System Attitude Control Motor Test-fired

Orion Launch Abort System Attitude Control Motor Test-fired
NASA, Alliant Techsystems (ATK) and Lockheed Martin celebrated a major milestone with a ground test of a full-scale attitude control motor (ACM) for the Orion crew exploration vehicle’s launch abort system (LAS).

"The completion of the Demonstration Motor 1 hot-fire test is a substantial advancement in developing the ACM," said LAS Manager Kevin Rivers, of NASA’s Langley Research Center in Hampton, Va. "With an elaborate eight-valve control system that relies on advanced ceramic composites for several key components, the ACM is among the most complex solid rocket systems ever built."

The test performed at ATK’s facility in Elkton, Md., was the sixth in a series of ground tests of Orion’s attitude control motor system. The ACM is charged with keeping the crew module on a controlled flight path after it jettisons, steering it away from the Ares 1 crew launch vehicle in the event of an emergency, and then reorienting the module for parachute deployment.

Having reached this milestone brings Constellation another step closer to flight-ready status and demonstrates progress toward improved flight safety for astronauts, which is at the core of Constellation Program success.

The launch abort system, mounted on top of the Orion crew module, centers around three solid propellant rocket motors: an abort motor, an attitude control motor; and a jettison motor. Successful tests of both the abort and jettison motors were completed in 2008. The attitude control motor consists of a solid propellant gas generator, with eight proportional valves equally spaced around the outside of the 32-inch diameter motor. Together, the valves can exert up to 7,000 pounds of steering force to the vehicle in any direction upon command from the crew module.

"Controllable solid rockets have only recently begun seeing application in spacecraft, and the ACM delivers an order of magnitude greater thrust than any of those systems," said Rivers. "It represents a significant technical advancement in controllable solid propulsion."

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