Aerojet Rocketdyne Holdings Inc. announced Monday it is partnering with the United Launch Alliance and the U.S. Air Force on a new rocket engine to launch military payloads into Earth orbit.

The AR1 engine would replace the Russian-built RD-180 engines currently used for launches of Atlas V rockets.

Key members of the AR1 design team work out of Aerojet Rocketdyne’s Chatsworth campus. Design and fabrication on the engine, including the use of 3-D printers to make parts, is being done in the San Fernando Valley as well.

The agreement between Aerojet Rocketdyne, in Sacramento, United Launch Alliance, in Centennial, Colo., and the Air Force is valued at $804 million for the engines that will be delivered by the end of 2019. The two companies will initially contribute $57.7 million to the project, with a total investment of $268 million if all options are exercised.

Aerojet Rocketdyne Chief Executive Eileen Drake said the award from the Air Force recognizes the priority of assuring access to space for military payloads.

“The AR1 engine is the option with the least technical risk that allows the United States to quickly and efficiently transition off its use of Russian-supplied engines,” Drake said in a prepared statement.

Aerojet Rocketdyne had already been at work on the AR1 prior to the announcement of the partnership agreement. The company also announced Monday that Dynetics, in Huntsville, Ala., will supply elements of the AR1 engine’s main propulsion system, the ignition system and ground support equipment.