Hot-fire tests have validated the design of the preburner for the AR1 rocket engine developed by Aerojet Rocketdyne to replace the Russian-built RD-180 engine currently used to launch most U.S. national security payloads into space.

The preburner, a critical component that drives the engine's turbomachinery, was built using state-of-the-art techniques, including 3-D printing, which features Aerojet Rocketdyne's proprietary Mondaloy™ high-strength, burn resistant nickel-based super alloy. Use of this material eliminates the need for exotic metal coatings used in the Russian-made RD-180 engine.Aerojet Rocketdyne tests its AR1 engine preburner at NASA's Stennis Space Center, MS. Image credit: Aerojet Rocketdyne

Using an advanced oxidizer-rich staged combustion engine cycle, the liquid oxygen/kerosene AR1 will generate 500,000 lbf of thrust at sea level. The thrust class enables the engine to be easily configured for use on multiple launch vehicles, including the Atlas V and the Advanced Boosters being considered for NASA’s Space Launch System.

The AR1 engine development is using the same rigorous methodology the company has used for its previous successful engine development programs, such as the RS-68, J-2X, RL10, and RS-25. Prior to full engine testing, the company is testing critical components and systems to validate the flight designs, ensuring that they are each robust prior to completing the flight engine design. Hundreds of component and subsystem tests along with manufacturing demonstrations have already occurred on the AR1 engine in advance of full engine testing.

The engine design team has now successfully completed a series of 22 component Critical Design Reviews leading up to an engine system Critical Design Review to support engine qualification and certification in 2019.