Aerojet Rocketdyne has successfully completed hot-fire qualification tests of its MR-104J liquid-fueled rocket engine. When Boeing's Crew Space Transportation (CST)-100 Starliner crew module makes its first manned flight in August 2018, 12 of these human-rated reusable engines will be installed in the capsule to provide thruster maneuverability during re-entry into the Earth's atmosphere.

Conducted at Aerojet Rocketdyne's facilities in Redmond, Washington, the tests of the hydrazine monopropellant engine were designed to demonstrate its ability to fulfill the reusability requirements for Boeing's propulsion system under the company's Commercial Crew Transportation Capability subcontract. The equipment can now be sent on to Boeing for installation in the Starliner spacecraft at its Commercial Crew and Cargo Processing Facility at NASA's Kennedy Space Center in Florida.

Intended to ferry astronauts and cargo to and from the International Space Station, the Starliner's primary propulsion system is housed in its Service Module, but the MR-104J rockets are needed after the module is jettisoned prior to reentry. The new engine shares many features with other reaction control systems, but is designed for better redundancy and improved strength to withstand the shocks of multiple firings over several missions.

In addition to the MR-104J, Aerojet Rocketdyne also builds the Starliner's Launch Abort Engines, Orbital Maneuvering and Attitude Control thrusters, and Service Module Reaction Control System thrusters.

"Our engineers have incorporated a unique design that will allow the MR-104 engine to be used on multiple missions, providing the reliability, cost-efficiency and reusability our customer needs to be competitive in the current commercial space environment," says Aerojet Rocketdyne CEO and President Eileen Drake. "We look forward to delivering the engines for the crew module and continuing our proud heritage of enabling astronauts to fly to the International Space Station from US soil."