COLORADO SPRINGS, Colo. — A decision on whether a Blue Origin or Aerojet Rocketdyne engine will power United Launch Alliance’s future Vulcan rocket will be coming “very soon,” ULA’s president and CEO said April 17.

How soon?

“Soon,” Tory Bruno, who has led ULA since 2014, told Defense News in an exclusive interview at Space Symposium.

Perhaps when Blue Origin wraps up hot fire tests of its BE-4 engine? Or when the U.S. Air Force selects three companies to continue developing launch systems this summer?

Bruno takes out a notebook and flips it open. The word “SOON” is printed in all-caps across the page.

“As you come closer in a competitive selection, you find that it’s harder to be as open,” he explained.

The Air Force is slated to pick up to three competitors for the next phase of its evolved expendable launch vehicle, or EELV, program this summer. During the “launch services agreements” phase, companies and the government will enter into private-public partnerships to fund the development of next-generation launch systems.

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The ultimate goal is for the Defense Department to emerge with two competitive options capable of launching national security payloads into space using domestic rocket motors. ULA’s Atlas V rocket, which until recently was the Air Force’s dominant launch system, is powered by a Russian-made RD-180 for its first stage.

ULA had planned to pick either Blue Origin’s BE-4 engine or Aerojet Rocketdyne’s AR1 to power the first stage of its upcoming Vulcan rocket by the end of 2017, Bruno told Defense News last year. However, that deadline — and the first BE-4 hot fire tests — came and went without a decision from ULA.

“Testing is going well, I think it is common knowledge that Blue is testing at the full-scale level. Aerojet is testing at component full scale, and subscale for integrated set. They’re both doing well. Beyond that I can’t really say much more other than we will select soon,” he said.

It’s unclear whether ULA’s proposal for the EELV competition included a BE-4 powered Vulcan, an AR1-powered Vulcan, or both options — and Bruno wouldn’t confirm either way, noting that source selection is ongoing.

ULA has been leaning toward the Blue engine, which has mostly been funded by internal investments by Blue Origin and could be ready for qualification by the end of the year. But the engine is the first of its size to use methane as a propellant, which could introduce the possibility of combustion instability and has caused ULA to keep its options open until Blue Origin proves its engine works.

The AR1 is fueled with kerosene and liquid oxygen, the same as the RD-180, and is seen as the lower-risk entry. But its development has lagged behind the BE-4, with certification slated for 2019.

While ULA still hasn’t make a public decision on which engine to adopt, it’s been a busy year on the Vulcan program, Bruno said.

After the EELV request for proposals was issued last year, ULA decided to make a big change to its Vulcan design. Instead of using its Centaur upper stage, which was also used on the Atlas V, the company opted to speed up development of the Centaur 5, Bruno said. The newer stage will have a larger propellant tank that’s about 5.4 meters in diameter, compared to its predecessor’s tank, which is about 3 meters in diameter.

“It gives us much larger payloads for the more complicated orbits right out of the gate,” he said.

It also gives ULA on the head start of Advanced Cryogenic Evolved Stage, or ACES, a future upper stage for Vulcan that is planned to be reusable. ACES will have the same diameter of propellant tank as Centaur 5, Bruno said.

“It was something that we had been thinking about and planned to do later,” he said. “It did cause us to re-plan how the team would be distributed and how it would accomplish that. So yeah, there was a challenge — but not a huge challenge, and I wouldn’t characterize it as a surprise.”

So far, ULA has completed a critical design review for the Vulcan’s booster and a preliminary design review for its upper stage, with a critical design review planned for next year.

It has configured its facility in Decatur, Alabama, for Vulcan production with new tooling with a higher level of automation, and the company is building qualification hardware that it can test during the development process, Bruno said.

ULA has also been working on a new launch pad for Vulcan, and it’s reworking its launch tower to accommodate both Atlas and Vulcan.

Valerie Insinna is Defense News' air warfare reporter. She previously worked the Navy/congressional beats for Defense Daily, which followed almost three years as a staff writer for National Defense Magazine. Prior to that, she worked as an editorial assistant for the Tokyo Shimbun’s Washington bureau.

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