NASA and Alliant Techsystems (ATK) have unveiled a new vertical test stand at ATK’s facility in Promontory, UT, that will be used to support NASA’s Constellation program. The stand will be used to test-fire the full-scale abort motor for the launch-abort system, which sits atop the Orion crew exploration vehicle.
A full-scale inert motor, without oxidizer in the propellant, is now secured top end down in the test stand with nozzles pointing skyward. Engineers will be performing a final checkout of the test setup over the next several months.
The abort motor, which is designed to pull the crew module away from the Ares I launch vehicle in an emergency situation on the launch pad or during the first 300,000 ft after launch, stands more than 17 ft tall and 3 ft in diameter and is equipped with four nozzles. The motor’s manifold uses a reverse-flow technology to force hot gas through the manifold’s four nozzles, creating a pulling force. The hot gas exits the top of the motor, allowing the resulting plume to clear the crew module.
"We're breaking new ground with the development of this critical motor, which must have sufficient thrust to leave the vehicle quickly and get the crew to safety," said Ted Kublin, Lead Engineer for the propulsion abort motor at NASA's Marshall Space Flight Center in Huntsville, AL. "The launch abort system is one of the most vital components of the Orion spacecraft, requiring innovative engineering to ensure success."
A bench test firing of the abort motor’s igniter assembly was scheduled to take place in early June. The igniter assembly is a small rocket motor inside the abort motor that provides the ignition source for the motor propellant. Once ignited, the motor propellant burns at a very high rate, resulting in four individual plumes that are more than three times the motor length. Total abort motor burn time is 5 s and creates 500,000 lb of thrust. The majority of the high-impulse propellant is expended in the first 3 s, which corresponds with the critical time frame for the Orion crew module to escape from any potentially life-threatening situation.
After the vehicle is safely away from the booster, a canard section will be deployed to reorient the capsule before the crew module is released from the abort system to begin its controlled descent.
The abort system is a key element in NASA's effort to improve safety as it develops the next generation of spacecraft to return humans to the moon. NASA's Langley Research Center in Hampton, VA, manages the launch abort system design and development effort with partners and team members from Marshall.
Langley's Launch Abort System Office performs this function as part of the Orion Project Office located at NASA's Johnson Space Center in Houston. Orbital Sciences Corp. of Dulles, VA, is building the entire launch abort system for Orion’s prime contractor, Lockheed Martin Corp.
Two pad abort tests are scheduled as well as an ascent abort test. These tests will provide early data for the design reviews to follow. The first pad abort test will verify all launch abort system components can function properly as a system; the second pad abort test will incorporate any design changes resulting from the pad and ascent abort tests.
The first crewed mission is scheduled for no later than 2015, and the first lunar excursion is scheduled for the 2020 time frame.