Spaceflight Insider

NASA signs SAA with Aerojet Rocketdyne to use Stennis test stand for AR1 engine

NASA Stennis Space Center welcome sign Mississippi photo credit Jason Rhian SpaceFlight Insider

NASA's Stennis Space Center has entered into a Space Act Agreement with Aerojet Rocketdyne to develop systems to test the AR 1 rocket engine. Photo Credit: Jason Rhian / SpaceFlight Insider

NASA’s Stennis Space Center in Mississippi and rocket engine manufacturer Aerojet Rocketdyne have signed a Space Act Agreement (SAA ) for testing of the latter’s AR1 multi-element pre-burner and main injector. The AR1 is considered to be an important offering as it is one of several domestically-produced rocket engines which could end U.S. dependence on Russian-built engines.

The AR1 is being developed for possible use on United Launch Alliance’s (ULA ) Atlas V family of launch vehicles, which currently use the NPO Energomash RD-180 rocket engine in the booster’s first stage. When asked, representatives with the company provided details as to what would occur at the E1 test stand.

“Key modifications of the Stennis E1 Cell 2 include upgrades to the pressurization and propellant feed systems and integration of the Aerojet Rocketdyne-provided test hardware,” Aerojet Rocketdyne’s Glenn Mahone told SpaceFlight Insider.

According to the company, this agreement builds on the current assembly and testing of the company’s RS-68 and RS-25 engines at NASA’s Stennis Space Center. AR will now utilize an incremental approach to implement this plan.

“The AR1 Program is using a stair-step approach to validation and verification testing to incrementally reduce technical and programmatic risk. Incremental testing of key hardware allows risk to be reduced as the design is matured. Testing at the sub-scale and full-scale component levels can be conducted more cost-effectively than waiting for full engine-level testing. It can also be conducted earlier in the overall engine development cycle, allowing knowledge gained to be incorporated into the full-scale engine,” Mahone said.

Under the SAA, Aerojet Rocketdyne will pay NASA’s Stennis Space Center to modify the E-1 Complex cell 2 during a period that should last about half a year. The modifications should see the test stand configured to support AR1 staged combustion testing.

“This is another example of Aerojet Rocketdyne’s focus to maintain schedule for the United States to be able to have AR1 ready to fly in 2019, to keep our country on track to end dependence on Russian engines,” said Aerojet Rocketdyne’s Julie Van Kleeck, vice president of Advanced Space & Launch.

Hot-fire testing of a multi-element preburner injector for the AR1 rocket engine. Photo Credit: Aerojet Rocketdyne

Hot-fire testing of a multi-element pre-burner injector for the AR1 rocket engine. Aerojet Rocketdyne recently conducted a hot-fire test of a similar multi-element injector built using additive (3-D) manufacturing this spring. Photo Credit: Aerojet Rocketdyne

AR1 single booster engine – Aerojet Rocketdyne.

CGI rendering of an AR1 single booster engine. Image Credit: Aerojet Rocketdyne.

The AR1 has two combustion devices, a pre-burner and main injector/combustion chamber. These two components are crucial to the operation of the rocket engine. Aerojet Rocketdyne has maintained a busy schedule recently, conducting a subscale pre-burner hot-fire testing at NASA Marshall Space Flight Center in Huntsville, Alabama.

The AR1 rocket engine is described as being capable of producing an estimated 500,000 pounds-force (2.2 MN) of thrust at sea level and is equipped with an oxygen-rich staged combustion kerosene technology that should allow it to be used on an array of U.S. boosters.

“We are using a stair-step approach to eliminate the highest risk items first in our AR1 engine development program to ensure earliest possible delivery,” Van Kleeck said. “By incorporating additive manufacturing and other new processes, materials and techniques into our plan, we offer the Nation a timely, cost-efficient path to end reliance on the Russian engines.”

Aerojet Rocketdyne has been working to be at the forefront of the use of additive manufacturing, more commonly known as 3-D printing. It is hoped this relatively new technology will help to drive down the cost of sending payloads to orbit.



Jason Rhian spent several years honing his skills with internships at NASA, the National Space Society and other organizations. He has provided content for outlets such as: Aviation Week & Space Technology,, The Mars Society and Universe Today.

Reader Comments

An engine without a rocket…they used to be the leader…now they are the alternative…

Rumor has it that they actually intend to attach the engine to the rear end of a pig.

⚠ Commenting Rules

Post Comment

Your email address will not be published. Required fields are marked *