The abort motor will provide a half-million pounds of thrust to lift the crew module off the Ares I rocket, pulling the crew away safely in the event of an emergency on the launch pad or during the first 300,000 feet of the rocket’s climb to orbit. Thursday’s firing was the first time a motor with reverse flow propulsion technology at this scale has been tested and was also the first test of its kind since the initiation of the Apollo Program. Last Thursday’s test firing was the culmination of a series of motor and
component tests conducted this year in preparation for the next major
milestone, a test scheduled for the spring of 2009 with a full-size
mock-up of the Orion crew capsule.
The abort motor stands more than 17 feet tall and is three feet in diameter. During Thursday’s ground firing, the motor was fixed in a vertical test stand with its four exhaust nozzles pointing skyward at ATK’s facility. On ignition, the abort motor fired for 5.5 seconds. The high impulse motor was developed to expend the majority of its propellant in the first three seconds, delivering the half million pounds of thrust needed to pull the capsule away from its launch vehicle in an emergency abort. The launch abort motor uses a composite case and an exhaust turn-flow technology instead of a tower, which results in weight savings, improved performance, and improved success in crew survival during an abort. Instead of the rocket plume exiting a rear nozzle, the manifold is placed at the forward end of the motor. The rocket thrust enters the manifold and is turned 155 degrees and forced out the four nozzles, creating a forward-pulling force.
