Aerojet Rocketdyne announced that assembly and testing of its AR1 advanced liquid rocket engine will take place at NASA’s Stennis Space Center in Mississippi. As a result, the company is expanding its Center of Excellence for Large Liquid Rocket Engine Assembly and Test there. The AR1 is being developed to support the country's mandate to eliminate U.S. reliance on the Russian RD-180 engine for national security space launches by 2019.
History will not be kind to the AR1 program. It’s a fairly expensive development program focused on building an American alternative to the RD-180, an engine used on a launch vehicle that will be phased out within 3-ish years of when the AR1 would be completed.
The AR1 is in competition with the BE-4 for use on ULA’s Vulcan. The BE-4 is at least a full year ahead of the AR1, and is expected to be tested in full by the end of 2016. It’s probably no coincidence that ULA expects to make a decision between the two in the same timeframe as the BE-4 test.
Outside of Atlas V and Vulcan, no one seems to be interested in AR1. Can anyone say pork?