FB: Too fast? Air Force leaders warn Congress the move away from the Russian-made RD-180 could limit the service's ability to launch

​Pentagon and Air Force officials Friday today warned lawmakers that a cCongressional push to limit the use of a Russian-made rocket engine, and the development of a U.S.-made alternative, is an aggressive approach islikely to extend to movebeyond the 2019 deadline. It might eventually push the United Launch Alliance out of national security space missions altogether.

Gen. John Hyten, commander of Air Force Space Command, told the House Armed Services Committee today that the Senate Armed Services Committee's push to stop all use of the Russian-made RD-180 engine, which is used on national security payloads, is "aggressive."

Representatives from possible entrants into the selection for the new engine – United Launch Alliance, SpaceX, Orbital ATK, Aerojet Rocketdyne and Blue Origin – told the committee earlier Friday today that they could get their rockets ready by the 2019 deadline. However, Hyten warned, those rockets would still need to be certified, and launch systems would need to be adjusted to work with the new rockets, adding years until a new launch system would be ready.

"It's possible to get there in 2019," Hyten said. "The skepticism … is there are significant technical challenges in a couple areas."

Even a copy of the RD-180 engine built to drop in to a ULA Atlas V would take years to develop by accounting for even minor changes in engineering, said Lt. Gen. Samuel Graves, commander of the Air Force Space and Missile Center. There would be modifications to launch vehicle structures, fuel systems, heat shields, thrust vector control and throttling, all adding time to an already tight deadline.

"Every rocket is heavily influenced by the design of its engine," Greaves said. "To do otherwise produces outcomes that are suboptimal in terms of performance, safety, cost and development timelines. You cannot simply drop in a replacement rocket engine without extensively re-engineering the entire launch system."

Michael Griffin, the deputy chair of an RD-180 Availability Risk Mitigation Study, said the Senate's action is "too abrupt," and does not allow the Pentagon to wean itself off of the Russian engine. Years of delays for development of the entire new system could mean delays on payloads getting into orbit, and cost overruns. Instead of leaning on industry, Griffin told lawmakers they should view the rocket development like a new weapons system, and purchase a system instead of buying launches from commercial providers.

"We must ensure, from cradle to grave, in the national security community that we can get everything we need," Griffin said.

While Senate leaders, especially Armed Services Committee chairman Sen. John McCain, R-Arizona, are anxious to completely stop the use of the RD-180, House lawmakers were more accepting to the need to keep some of the rockets available to keep assured access to space.

"In other areas of national defense, we wouldn't think about phasing out a capability until we had confidence in a follow on," said Rep. Mike Coffman, R-Colorado. "We are anxious to phase out the RD-180 engine without full confidence that a robust capability will replace it."

The Senate Armed Services Committee's version of the fiscal 2016 National Defense Authorization Act limits the Pentagon's amount of Russian RD-180 rocket engines to nine, and calls on multiple U.S. companies to produce rockets and launch systems by 2019. The Air Force wants to be able to buy 14 more of the engines to be able to cover launches until 2022.

The limited amount of rockets, used in the United Launch Alliance Atlas V system, means the stockpile would run out likely before new systems are certified and ready. Without a promised revenue stream, ULA could not be able to compete with upstart SpaceX, should that company be certified for all launches, Hyten said.

The move would effectively shift the monopoly from ULA, a joint venture of Lockheed Martin and Boeing, to SpaceX, he said.

"(ULA) is asking for time to transition between where we are today and whatever their new system is," Greaves said. "They need a steady stream of revenue to maintain capability. If the Delta IV is forced to compete with the Falcon 9, it would not be cost competitive. Without the assurance of a steady stream of revenue, it would be hard to receive the capital investment they need."

Tory Bruno, the president and chief executive officer of ULA, urged the committee to change the law to keep more rockets available.

"If current law is not modified, America will no longer be compliant with its assured access to space policy as competition will have been unintentionally eliminated," Bruno said in testimony to the committee. "Our efforts to field a new launch system with an American-made engine hinge on our ability to close a business case justifying the significant corporate investment we will have to make to field this system."

Last month, the Air Force certified SpaceX for some military space launches. Jeffrey Thornburg, SpaceX's senior director of propulsion engineering, said in testimony Friday today that the company will first fly its large launch system, the Falcon Heavy, later this year and, once certified, the company would be able to carry all national security payloads with American-made systems.