Aerojet Rocketdyne [AJRD] in August completed critical design reviews (CDR) for the jettison motor and crew module reaction control system (RCS) it is developing for NASA’s Orion crew module, according to a company statement.
Aerojet Rocketdyne is now able to begin manufacturing hardware for installation into Orion for Exploration Mission-1 (EM-1), which is slated for launch readiness in 2018. This would also be the first flight of NASA’s Space Launch System (SLS) rocket. Aerojet Rocketdyne Program Director for Human Space Samuel Wiley said Thursday in an interview passing CDR also means the company will enter into more rigorous qualification testing.
The jettison motor is a solid rocket motor that Wiley said provides about 40,000 pounds of thrust for about 1.5 seconds, separating the launch abort system from the Orion spacecraft in about five seconds after fairing separation. This allows the crew to continue safely on their way to deep space. Wiley said Aerojet Rocketdyne is slated to perform additional development testing on the jettison motor early next year and will also perform initial hot fire testing about mid-2016. Company spokesman Glenn Mahone said jettison motor delivery is slated for mid-2017.
In addition to its normal operations, the jettison motor serves another purpose if a launch anomaly occurs. Designed to assist crew escape, the jettison motor is one of three solid rocket motors on the launch abort system that will rapidly pull the capsule away from the stack in the event of an emergency. An Orion pad abort test was successfully performed in 2010 at White Sands Missile Range, N.M. Orion is developed by Lockheed Martin [LMT].
The crew module RCS provides the only course control authority after separation from the service module. It ensures the heat shield is properly oriented, that the crew module is stable under the parachutes and that the vehicle is in the correct orientation for the splashdown. Wiley said Aerojet Rocketdyne is building the rocket engines on the crew module hardware with a goal of rocket engine acceptance testing in the spring. Crew module hardware, he said, is slated for mid-summer delivery.
Wiley said the crew module RCS is composed of 12 mono propellant engines and each provides about 160 pounds of thrust. Using hydrazine as fuel, the engines use a series redundant rocket engine to put hydrazine across the catalyst bed, which makes hot nitrogen, hot hydrogen and a little ammonia to expand hot gas out of the nozzle to create the thrust, Wiley said. He added that the engines provide redundant pitch, yaw and roll control of the crew module.
Primarily, Wiley said, the RCS is activated when Orion re-enters earth’s atmosphere. He added on a normal flight, the service module separates, the crew module RCS is activated and performs the steering and positioning to properly align at the entry interface. Wiley said the engines are fired all the way to splashdown because they are used to steer while the crew module floats under parachutes.
In other Orion news, NASA on Oct. 13 appointed Mark Kirasich to serve as program manager. Kirasich has been deputy Orion program manager since 2006. He now will be responsible for oversight of design, development and testing of the Orion spacecraft, as well as spacecraft manufacturing already underway at locations across the country and in Europe for ESA (European Space Agency), according to an agency statement.