United Launch Alliance (ULA) has selected Blue Origin’s BE-4 engine to power its Vulcan Centaur rocket, the alliance said Thursday.

The alliance, which is a joint venture between Lockheed Martin [LMT] Space Systems and Boeing [BA] Defense, Space and Security and produces the Delta IV and Atlas V launch systems, said the engine will fuel the next-generation rocket’s booster stage. The liquefied natural gas-fueled booster will be powered by two BE-4 engines, each producing 550,000 pounds of sea-level thrust, according to a ULA statement.

Blue Origin's BE-4 engine (Photo: Blue Origin)
Blue Origin’s BE-4 engine (Photo: Blue Origin)

The BE-4 engine will replace the Russian-made RD-180 engine currently used to power the first stage of the Atlas V rocket. The fiscal year 2017 National Defense Authorization Act (NDAA) prohibited the use of RD-180 engines on U.S. platforms beginning in 2022, as rising tensions with Moscow have encouraged the U.S. military and defense industry partners to search for domestically made alternatives. Blue Origin, which is founded by Amazon co-founder Jeff Bezos, plans to build the BE-4 engines in Huntsville, Alabama, the company said in 2017.

ULA was also evaluating Aerojet Rocketdyne’s [AJRD] AR-1 engine for Vulcan Centaur’s booster stage. Both companies received research-and-development contracts from the Air Force in 2016 for work on the new engine.

The alliance in May selected Aerojet’s RL-10CX engine for the upper stage of the rocket. ULA also previously chose Northrop Grumman’s [NOC] solid rocket boosters, L-3 Avionics Systems’ [LLL] avionics and Switzerland-based RUAG’s payload fairings and composite structures for the new rocket system.

Steve Warren, Aerojet’s chief communications officer, said Friday in a statement that the company remains focused on manufacturing a full-scale AR-1 engine to be test-ready in 2019.

“We designed AR-1 to be configurable to multiple launch vehicles, which is why we will continue to mature the AR-1 engine for integration with other small to medium-class launch vehicles,” he said.

Analysts from Jefferies Research Services noted Thursday evening that Blue Origin’s offering has long been considered the front runner of the competition, and cost was likely the determining factor. 

The Vulcan Centaur is making “strong progress” in development and is on track for an initial flight in mid-2020, according to a statement from ULA. The next-generation rocket’s design leverages the success of both of those launch vehicles while including advanced technologies, the alliance said.

“With state-of-the-art engineering and manufacturing techniques, this rocket is designed specifically for low recurring cost,” Tory Bruno, ULA’s president and CEO, said in an emailed statement.

The new rocket design is nearing completion, and the booster preliminary design and critical design reviews are complete, ULA said. The system will have a maximum liftoff thrust of 3.8 million pounds and carry 56,000 pounds to low Earth orbit (LEO), 33,000 pounds to a geo-transfer orbit and 16,000 pounds to geostationary orbit (GEO). The rocket’s Air Force certification plan is in place, Bruno said.

The alliance was also awarded an $867 million cost-plus-incentive-fee, cost-plus-fixed-free, firm-fixed-price modification to the Air Force’s evolved expendable launch vehicle (EELV) launch capability for the Delta IV and Atlas V families of systems, the service said Thursday. The contract modification includes mission integration, base and range support, maintenance commodities and depreciation of both systems.

Work will be performed in Centennial, Colorado, as well as at Vandenberg Air Force Base, California, and Cape Canaveral Air Force Base, Florida. Work is expected to be complete by the end of fiscal year 2019 (FY ’19). The total face value of the EELV contract is worth over $9.7 billion.