Boeing CST-100 OMAC Thrusters Tested In New Mexico
September 21, 2013

Boeing Tests New CST-100 Spacecraft Thrusters

April Flowers for – Your Universe Online

After a gauntlet of test firings of the steering jets conducted at White Sands Space Harbor in Las Cruces, New Mexico, the Boeing's CST-100 spacecraft is closer than ever to liftoff.

The tests, which simulated the demanding environment of space, were recently completed by Boeing and Aerojet Rocketdyne to assess how the thrusters -- which fire with 1,500 pounds of force -- will speed up, slow down and move the spacecraft while carrying NASA astronauts in Earth orbit.

In partnership with NASA's Commercial Crew Program (CCP), Boeing is developing a fully integrated crew transportation system, which includes the CST-100 spacecraft and the United Launch Alliance Atlas V rocket. Eventually, commercial spaceflight capabilities being developed by NASA partners through CCP initiatives could provide services to transport astronauts to and from the International Space Station (ISS), launching from American soil. Currently, Boeing is working on development milestones that are part of NASA's Commercial Crew Integrated Capability (CCiCap) initiative.

"Boeing and Aerojet Rocketdyne continue to show a path forward for NASA's low-Earth orbit crew transportation needs by implementing cutting-edge technologies and showcasing decades of human spaceflight experience," said Ed Mango, CCP manager.

The orbital maneuvering and attitude control (OMAC) system for the CST-100 has 24 thrusters. This gives it the ability to perform critical maneuvers in space, such as those required to refine the CST-100's orbit, as well as the braking maneuver near the end of a mission that slows the spacecraft before re-entry. Just before re-entry, the OMAC thrusters will be jettisoned as the service module is released from the capsule. The 24 thrusters are arranged in four groups of six on the outside of the service module in such a way that, in the event that an emergency calls for it to separate from its rocket during launch or ascent, they could steer the spacecraft.

The tests called for the OMAC thrusters to be fired in a vacuum chamber that simulated the space-like environment at an altitude of 100,000 feet. This type of testing put the thrusters through the burns and stresses they would encounter during a real flight. To measure changes in even the smallest components, engineers fitted the jets with a host of instruments before the tests.

"The CST-100 OMAC thrusters are an example of leveraging proven flight hardware solutions to ensure mission supportability," said John Mulholland, Boeing vice president and manager for commercial programs. "We are very pleased with the data collected during this second series of tests and with our overall team performance as we continue to progress through CCiCap milestones on time and on budget."

The OMAC thrusters have been tested previously to verify their durability in extreme heat, evaluating the opening and closing of their valves and confirming continuous combustion and performance. The results of these tests are being used by designers to validate or adjust their complex computer models that predict how a thruster and spacecraft will work during a mission.

"The OMAC engines met CCiCap test objectives," said Terry Lorier, Aerojet Rocketdyne's CST-100 Service Module Propulsion Program manager. "Aerojet Rocketdyne and Boeing are both pleased with the results and look forward to continuing our partnership."

These tests represent the ninth milestone completed, putting Boeing on track to meet all 20 of its CCiCap milestones by summer 2014. Boeing, and all of NASA's industry partners, continues to meet their established milestones in developing commercial crew transportation capabilities.