COLORADO SPRINGS, Colo. — For years, there’s been a big question surrounding the next-generation BE-4 rocket engine that’s being built by Amazon billionaire Jeff Bezos’ Blue Origin space venture: Will it be good enough for United Launch Alliance, a crucial prospective customer?

Now Blue Origin CEO Bob Smith says the BE-4 has passed all of the technical tests required for ULA to sign onto a production contract.

“We’ve met the technical and performance requirements that they’re looking for,” Smith told GeekWire today during a one-on-one interview at the 34th Space Symposium in Colorado Springs. “And so we’re just working through how do we actually get to a production deal. We’re working through terms and conditions, termination liability, all of the things you’d want within a contractual structure.”

Smith said there’s been good interaction with ULA on the technical side of the BE-4 test-firing process. “At this point, we think it’s just, how do we get to the commercial production deal?” he said.

Bringing the BE-4 project to fruition ranks among the highest priorities for Smith, a veteran aerospace executive whom Bezos brought in to fill the newly created role of chief executive officer last year.

Blue Origin and ULA joined forces back in 2014, with the objective of putting the BE-4 engines on ULA’s next-generation Vulcan rocket. The BE-4 is designed to be used on Blue Origin’s orbital-class New Glenn rocket as well. Both rockets are supposed to enter service by 2020.

If ULA gives the go-ahead, Blue Origin plans to ramp up BE-4 engine production, which is currently being done at the company’s main facility in Kent, Wash. A big part of the ramp-up would involve opening up a new engine factory in Huntsville, Ala.

But ULA is still keeping its options open, just in case it can’t strike a deal with Blue Origin. Plan B focuses on Aerojet Rocketdyne’s AR1 rocket engine. During a meeting with journalists earlier in the week, Aerojet CEO and President Eileen Drake said “we are well on our way to produce the first engine.” AR1 test firings are due to begin next year, she said.

“At the end of the day, we will be able to offer … an engine like no other engine in the United States,” Drake said. “It will have a lot of applicability.”

United Launch Alliance CEO Tory Bruno has shied away from providing a precise timetable for making the decision on the engine, other than to say it’ll be made “soon.” ULA spokeswoman Jessica Rye declined to comment specifically on Smith’s remarks, but noted that engine selection would be part of a competitive procurement process.

For those who are wondering when @ulalaunch is going to chose between @blueorigin 's BE-4 and @AerojetRdyne 's AR1 engine for its Vulcan rocket, here is @torybruno 's official answer. #34SS pic.twitter.com/DF8DOWct2e — Valerie Insinna (@ValerieInsinna) April 17, 2018

Getting the BE-4 qualified and into commercial production would mark a milestone for Blue Origin, and improve the status of Bezos’ company with respect to fellow billionaire Elon Musk’s SpaceX.

The road hasn’t always been smooth: Last May, Bezos reported that an engine powerpack was lost during a round of testing at Blue Origin’s West Texas facility.

Smith said Blue Origin learned lessons from that setback. “We incorporated a lot of changes associated with how do we deal with foreign object debris,” Smith said.

He said the 550,000-pound-thrust engine, which is fueled by liquefied natural gas, is still “very much in testing.” It hasn’t yet been cranked up to 100 percent of its maximum power, and it hasn’t yet been fired for full mission duration.

But Smith drew attention to a 114-second test firing at 65 percent power. That time duration is roughly half of what’ll be required for launch, he said. Other tests have throttled the engine between 40 percent and 70 percent power levels, or have fired the engine for longer than 114 seconds, Smith said.

Just as importantly, the BE-4 is meeting expectations for reusability. “The hardware looks excellent, so for a reusable launch vehicle that’s a great thing,” Smith said. The engine that went through Blue Origin’s first full-fledged test firing last October is on display at the Space Symposium.

Formal engine qualification is expected by the end of the year.

Smith said Blue Origin is designing the BE-4 to have a 100-mission lifetime. And he added that Blue Origin won’t stop with BE-4.

“We are a propulsion company at our core, and yes, there will be additional engines,” he said.

For example, Blue Origin recently announced that it would use a vacuum-optimized version of its hydrogen-fueled BE-3 engine on New Glenn’s second stage.

Smith said making the switch “wasn’t a particularly hard decision.”

“The rocket equation fundamentally says that: You want high thrust on the first stage, and you want to have high ISP [specific impulse] on the second stage,” Smith said. Liquid hydrogen can provide the high performance that Blue Origin and its customers will be looking for.

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