COLORADO SPRINGS, Colo. — In the wake of a blue-ribbon panel’s report urging the U.S. government to develop a domestic replacement for the Russian-built RD-180 rocket engine, the Senate Armed Services Committee drafted a 2015 defense authorization bill that provides $100 million for that purpose.

The bill, details of which were released May 22, calls for an American-made liquid rocket engine to be produced by no later than 2019, and in addition to the funding provided in 2015 it authorizes the Pentagon to spend $20 million this year on the effort. The bill also directs the Pentagon to stop using Russian-built engines once it launches all of the missions covered under an $11 billion contract with Denver-based United Launch Alliance for 36 rocket cores, provided a reasonably priced U.S. alternative is available.

That U.S. Air Force contract includes a mix of cores for ULA’s Atlas 5 rocket, which is powered by the RD-180, and the Delta 4, which has a U.S.-built main engine. Those vehicles currently launch the vast majority of U.S. national security payloads, although other companies, notably Space Exploration Technologies Corp. of Hawthorne, California, are trying to break into the market.

The House of Representatives on May 21 passed its version of the bill, providing $220 million next year for a new main rocket engine, so it appears likely that substantial funding will be in the 2015 budget for the effort.

The future availability of the RD-180 has come into doubt amid a sharp downturn in U.S.-Russian relations following Russia’s annexation of Crimea under President Vladimir Putin. The U.S. government has since sanctioned several senior Russian government officials including Deputy Prime Minister Dmitry Rogozin, who responded by issuing a ban on U.S. use of the RD-180 for military purposes.

“Mr. Putin’s Russia is giving us some problems,” Sen. Bill Nelson (D-Fla.), a member of the Armed Services Committee, said in a prepared statement May 22. “So we put $100 million in the defense bill to develop a state-of-the-art rocket engine to make sure that we have assured access to space for our astronauts as well as our military space payloads.”

Meanwhile, an expert panel has completed work on an “RD-180 Risk Mitigation Study” that cited “significant” impacts if the access to the engine is lost, and recommends that the U.S. government embark on an effort to develop a liquid-oxygen (LOX)-hydrocarbon-fueled alternative. The report said the Air Force’s ability to mitigate these impacts in the near term is limited.

The study was chaired by retired Air Force Maj. Gen. Howard J. “Mitch” Mitchell, vice president of program assessments at the Aerospace Corp., with Mike Griffin, the former NASA administrator and now chief executive of the Schafer Corp., serving as deputy chairman. The report’s 20-page executive summary was obtained by SpaceNews.

According to the study, there are 38 Atlas 5 missions on the U.S. manifest, but only 16 RD-180 engines in ULA’s stockpile. The report was completed before ULA launched a classified satellite on an Atlas 5 May 22.

Should that mission be the last RD-180 ever flown — the report cited this as a “worst case” scenario — 31 missions would be delayed for an average of 3.5 years, and an additional eight heavy-lift rockets would be needed, the summary said. That would cost U.S. taxpayers about $5 billion, it said.

If ULA is allowed to fly only the remaining RD-180s it currently has in inventory, nine missions would be delayed by an average of two years, with no additional heavy launchers — presumably the triple-core Delta 4 Heavy — needed, the report said. Taxpayers would be out some $2 billion under that scenario, which also would require the government to prioritize among U.S. national security, intelligence, weather and science missions, the report said.

Michael Gass, chief executive of ULA, has raised the possibility of accelerating Delta 4 production if the Atlas 5 is grounded, but the report said that cannot happen quickly enough to avoid delays. The report said only one new entrant — presumably SpaceX — is expected to be certified to launch national security missions by 2017, and called the schedule for certifying that initial new entrant by late 2014 as “aggressive.”

In the near term, the report recommended that ULA accelerate its current RD-180 procurement to keep the missions under the 36-core block buy on schedule and to facilitate the upcoming first competitive phase of the Air Force’s Evolved Expendable Launch Vehicle program. The Air Force and ULA also should complete dual integration of Atlas-only payloads.

Regardless of what happens with the RD-180, the United States needs to develop a new rocket engine, the report said.

The report calls on the Pentagon to issue an acquisition decision memorandum for development of a new LOX-hydrocarbon engine to support competitive national security launch procurements beyond 2022. This memorandum should include a next-generation launch vehicle, with full funding identified in the out-year projections that accompany the Air Force’s 2016 budget request, the report said.

NASA and the Air Force, meanwhile, should create a joint program office to manage the engine development effort, with $141 million in initial risk-reduction funding.

According to several industry sources, NASA has served notice that it is not interested in funding such an effort.

In an interview May 22 here, NASA Associate Administrator Robert Lightfoot said the agency will weigh in once it sees the direction the Air Force is headed, adding that there have been no formal meetings yet on the matter.

“We want to make sure we understand the whole strategy before we agree to any piece of the Mitchell report,” Lightfoot said. “We’ve talked to them about some of the stuff that concerns us. In the last couple of weeks.”

The RD-180 engine is built by RSC Energomash of Russia and sold to ULA by RD Amross, a joint venture of Energomash and United Technologies Corp. (UTC). When that arrangement was set up during the 1990s, the parties agreed that Energomash would transfer the technology and know-how necessary for UTC to co-produce that engine in the United States.

The report recommended against co-production, as does Gen. William Shelton, commander of Air Force Space Command.

Speaking with reporters May 20 here at the 30th Space Symposium, Shelton, who oversees Air Force space operations and procurement, cautioned that it is too early to tell whether Russia will make good on threats to restrict the use of the RD-180 to nonmilitary missions. He said there are “indications” that the engine will remain available on a “business as usual” basis, but declined to be specific.

Shelton nonetheless said it is his personal preference that the United States develop a domestic alternative, emphasizing that such a decision is not his to make.

“I don’t see us going into an RD-180 co-production mode,” Shelton said. “There will still be a reliance on Russian system engineering and subject matter expertise and all that. You haven’t necessarily solved the problem.”

Shelton also said previous studies have shown that the difference in price between RD-180 co-production and starting from scratch are negligible. “There’s not a financial savings and if one of the objectives is avoiding foreign reliance — you don’t get there in co-production,” he said.

Shelton said he does not know where the money for a new engine development program would come from. But he was emphatic that it should not come from the Air Force’s space budget, which he said has been stretched to the limit in recent years.

Developing a new rocket main engine could cost more than $1 billion and take from five to eight years. U.S. lawmakers told Shelton this year that it is their job to find the money.

“Personally what I would like to see us pursue is hydrocarbon boost,” Shelton said. “I don’t think LOX-kerosene is the way to go; certainly LOX-hydrogen is a thing of the past.”

Kerosene is considered a hydrocarbon fuel, as is liquid methane.

Executive Editor Warren Ferster and Staff Writer Dan Leone contributed to this report.

Mike Gruss covers military space issues, including the U.S. Air Force and Missile Defense Agency, for SpaceNews. He is a graduate of Miami University in Oxford, Ohio.

Warren Ferster is the Editor-in-Chief of SpaceNews and is responsible for all the news and editorial coverage in the weekly newspaper, the spacenews.com Web site and variety of specialty publications such as show dailies. He manages a staff of seven reporters...