After a four-year, high-profile competition, rocket maker United Launch Alliance announced Thursday that it has selected the BE-4 rocket engine manufactured by Blue Origin to power its new Vulcan Centaur rocket. The new space company founded by Amazon's Jeff Bezos defeated the most storied rocket engine manufacturer in the United States, Aerojet Rocketdyne, which is developing the AR1 engine.

"We are pleased to enter into this partnership with Blue Origin and look forward to a successful first flight of our next-generation launch vehicle," United Launch Alliance's chief executive, Tory Bruno, said in a statement Thursday. He added that the Vulcan rocket remains on track for an initial flight in mid-2020.

"We are very glad to have our BE-4 engine selected by United Launch Alliance," Blue Origin Chief Executive Bob Smith also said. "United Launch Alliance is the premier launch-service provider for national security missions, and we're thrilled to be part of [its] team and that mission. We can't thank Tory Bruno and the entire United Launch Alliance team enough for entrusting our engine to powering the Vulcan rocket's first stage."

A new, novel engine

The BE-4 engine is notable both for its power and the fact that it uses a relatively new rocket fuel, methane. With a sea-level thrust of 550,000 pounds, the engine is nearly 25 percent more powerful than the space shuttle's main engine. Moreover, it is the most powerful rocket engine ever designed and built to use methane, a fuel more dense than hydrogen and with a higher specific impulse than the commonly used form of kerosene known as RP-1.

The company's success is all the more significant because it was largely funded by Jeff Bezos without direct cost to taxpayers. Bezos likely spent nearly $1 billion financing it. (The US Air Force is paying for the majority of the AR1's development). Up until a few years ago, every US-based rocket engine was funded almost entirely through government contracts. SpaceX changed the model by building its Merlin rocket engine (190,000 pounds of thrust) largely on its own and then using nine of them to power the Falcon 9 rocket.

Throughout the competition, United Launch Alliance has maintained that it preferred the BE-4 engine to the one developed by Aerojet. This is partly because the BE-4 was expected to be completed sooner and probably also because it would cost the company less to buy, once complete. Each Vulcan rocket will use two engines.

Lobbying campaign

Despite this, Aerojet has significant lobbying clout and has pressed US lawmakers to use their influence over United Launch Alliance, which receives the majority of its launch contracts from the US Air Force for national security flights.

In February 2017, two US representatives with oversight over the Air Force, Mike Rogers (R-Ala.) and Mac Thornberry (R-Tex.), sent a letter to Lisa Disbrow, the acting secretary of the US Air Force, and James MacStravic, who was then performing the duties of the undersecretary of defense for acquisition, technology, and logistics. "The United States government must have a hands-on, decision-making role," the letter said, in regard to the design of the Vulcan rocket.

The letter went on to say the Air Force should not give any additional funding to United Launch Alliance, other than for current launch vehicles, until the company provides "full access, oversight of, and approval rights over decision-making" in its choice of contractors for the engines on Vulcan. The letter also asserted that the methane-fueled BE-4 engine was an "unproven" technology.

Blue Origin

Blue Origin

Blue Origin

Since then, however, Blue Origin has continued to design and test its engine, while Aerojet has not appeared to make significant progress. In October 2017, Blue Origin began hot-firing a full-scale version of the BE-4 rocket engine. Aerojet, meanwhile, began spending less of its own money on AR1 development and stopped internal funding of the engine altogether this spring. As Ars reported on Monday, this signaled that a decision in BE-4's favor was all but certain.

The decision sends a positive signal to the aerospace community, said Greg Autry, an assistant professor at the University of Southern California who studies commercial spaceflight. "If this was any other industry in the world, this would be a no-big-deal event," he said. "But because this industry has been so moribund for decades, it's a big deal. I think it's a very good sign for the industry to see a competitive process."

A “visionary”

In the past, during a competition such as this, Aerojet would have been the presumed winner because of its heritage of excellent—if costly—rocket-engine production. But the arrival of SpaceX during the last decade combined with Blue Origin's recent large rocket engine have led to a new era of competition and private investment generally known as new space.

For a more traditional company like United Launch Alliance, this competition is layered in complexity. Bruno's decision reflects the need to reduce the price of his launch vehicles in order to compete with SpaceX and its Falcon 9 and Falcon Heavy rockets for national security launches. He will be able to procure BE-4 engines at a likely substantially lower cost than the AR1.

But in making a deal with Blue Origin, he will also support a potential competitor. Although Jeff Bezos has said he will spend as much money on Blue Origin as needed to bring its powerful New Glenn rocket to the launchpad—it also uses BE-4 engines, seven of them—he will now also be paid by United Launch Alliance. This is despite the fact that, in a few years, New Glenn and Vulcan rockets will be competing for the same launch contracts, as well as those in the commercial market.

This certainly was not a decision easily made by Bruno, who has a doubly difficult job in that his company is jointly owned by Lockheed Martin and Boeing. "He's been a real visionary and risk taker," Autry said of Bruno. "And that's amazing, given the heritage of his company and the dynamic he's in, being in a company owned by two traditional aerospace companies."