WASHINGTON — Senior U.S. military space leaders told a House subcommittee April 3 they backed the idea of developing an American-made alternative to the Russian-made RD-180 that powers the core stage of the U.S. Atlas 5 rocket, but said breaking existing contracts to buy and use the engines would be expensive and risky.

Testifying before the House Armed Services strategic forces subcommittee, these officials said the idea made sense from a national security perspective and as a way to support U.S. businesses.

Concerns about the U.S. military’s reliance on the RD-180 have heightened in the wake of Russia’s occupation and subsequent annexation of Crimea. United Launch Alliance’s Atlas 5 is one of the two main workhorses for launching U.S. national security satellites, along with the company’s Delta 4 rocket.

The RD-180 is built by RSC Energomash in the Moscow region and sold to ULA by RD-Amross, a joint venture between the Russian manufacturer and United Technologies Corp. 

U.S. reliance on the engine was the dominant topic of the military space-themed hearing. The witnesses included Gen. William Shelton, commander of Air Force Space Command; Gil Klinger, deputy assistant secretary of defense for space and intelligence; Doug Loverro, deputy assistant secretary of defense for space policy; and Betty Sapp, director of the National Reconnaissance Office.

“I would be a strong supporter of [fielding a U.S. alternative to the RD-180] if we could find the money,” Shelton said.

Rep. Mike D. Rogers (R-Ala.), the subcommittee chairman, responded that finding the money was Congress’ problem and it was the military’s job to develop the strategy. Rogers said it was important to get the leaders on the record about their preference for a U.S.-made rocket engine. 

“I’m one of those agencies who’s very interested,” said Sapp, whose agency buys and operations the nations spy satellites. “Certainly we’d all feel better if they were built in the United States.”

Both the Defense Department and the Air Force are conducting studies on the use and implication of continued reliance on the RD-180 and the feasibility of an alternative to the engine.Shelton said he expects the Air Force’s report to be completed by the end of May.

Industry officials, including RD-Amross President and Chief Executive Bill Parsons, have said that while it is feasible to set up a domestic manufacturing line for the engine, doing so would significantly increase the engine’s price tag at a time when launch costs are a major concern among lawmakers and U.S. government officials.

In the meantime, Klinger outlined a Pentagon plan to deal with any interruption in RD-180 shipments should the relationship between the United States and Russia continue to sour. 

That plan includes increased reliance on ULA’s Delta 4 and on new entrants into the national security space launch market, such as Space Exploration Technologies Corp.’s Falcon 9. The plan also would take advantage of the stockpile of RD-180 engines at ULA’s factory in Alabama and evaluate designs for a next-generation U.S. rocket.

ULA currently has about a 2.5-year supply of Atlas 5 engines on hand in its factory and expects to take delivery of five engines next year and six in 2015. 

Lawmakers also asked during the hearing about the implications of breaking the U.S. Air Force’s promise to buy 36 rockets from Denver-based ULA on a sole-source basis. The service has already ordered the first batch of rockets under the so-called block buy, which is designed to save on unit costs through economies of scale. 

Klinger said the Defense Department does not have an exact value on breaking such a contract but estimated the cost would exceed $370 million.  

In addition, the witnesses said, the Defense Department would be forced to negotiate on a mission-by-mission basis for access to space, thereby driving up costs on a per-launch basis. Shelton said the Air Force also would have to pay to integrate national security payloads with a different booster than the Atlas 5. 

Follow Mike on Twitter: @Gruss_SN

Mike Gruss is a senior staff writer for SpaceNews. He joined the publication in January 2013 to cover military space. Previously, he worked as a reporter and columnist for The Virginian-Pilot in Norfolk, Va. and The Journal Gazette in Fort Wayne, Ind. He...