Rep. Mike Rogers (R-Alabama), above, said after a three-hour hearing he would prefer the Air Force re-engine the Atlas 5 rocket. Credit: C-SPAN.

WASHINGTON — The chairman of the House Armed Services strategic forces subcommittee wants the U.S. Air Force and launch industry to focus narrowly on replacing the Russian-made main engine on United Launch Alliance’s workhorse Atlas 5 rocket, as opposed to investing in various launch vehicle technologies.

“I want a new engine, I don’t want a rocket,” Rep. Mike Rogers (R-Ala.) said during a subcommittee hearing June 26. “My priority is to re-engine the Atlas 5.”

That sentiment puts Rogers squarely at odds with Denver-based ULA, which is pursuing a brand new launcher dubbed Vulcan whose planned methane-fueled main engine is incompatible with the current Atlas 5 design.

Congress mandated last year that the Defense Department develop a domestic propulsion system that by 2019 would be ready to replace the Atlas 5’s RD-180 main engine, whose future availability is in doubt due to the slide in U.S.-Russian relations. The Alas 5 today launches most U.S. government payloads.

Rogers pointed out that Congress authorized $220 million in 2015 specifically for a new engine. But the Air Force, wary of investing in an engine that none of its certified launch service providers — currently ULA and newcomer SpaceX — wants, has proposed spending that money more broadly on launch vehicle technology.

Rogers had a sympathetic witness during the hearing in Mike Griffin, the former NASA administrator who helped lead a recent Defense Department study that recommended replacing the RD-180 with an American-built alternative as soon as possible.

“This does nothing to solve today’s problems,” Griffin said of the Air Force’s current investment strategy. “And even if it did, it is irrational to suppose that an entirely new vehicle can be obtained more quickly or at less cost than a new engine alone.”

Griffin is chief executive of Schafer Corp., which is part of an industrial consortium including engine maker Aerojet Rocketdyne that has inquired about the possibility of obtaining production rights to the Atlas 5. Griffin said he testified due to his role on the RD-180 commission.

But Rep. Jim Cooper (D-Tenn.), the subcommittee’s ranking member, questioned the rationality of focusing exclusively on an apples-to-apples RD-180 replacement. “I’m a little worried we’re chasing a unicorn,” he said.

The Air Force in June released a solicitation calling for industry to move quickly to develop prototypes of new main-and upper-stage rocket propulsion systems. The service plans to award as many as four contracts worth a combined $160 million for the prototypes as early as September, and another $32 million for general booster propulsion technologies.

Julie Van Kleeck, vice president of advanced space and launch systems at Sacramento, California-based Aerojet Rocketdyne, said the Air Force is moving too slowly. Six months after lawmakers provided funding for the engine program, “virtually no money has been spent.”

In testimony, Air Force officials said they have spent about $50 million thus far and plan to spend another $50 million before the end of the year.

Van Kleeck characterized the Air Force’s situation as an engine problem, not a launch vehicle problem.

Air Force officials told lawmakers the problem is more complex.

“Assured access to space requires space launch services and not just a rocket engine,” said Lt. Gen. Samuel Greaves, commander of the Space and Missile Systems Center at Los Angeles Air Force Base, which acquires military space systems. He said the Air Force received a “broad response” from industry on its rocket technology solicitation.

Aerojet Rocketdyne is developing an engine dubbed the AR1 that, like the RD-180, is fueled by liquid oxygen and kerosene, and company officials say it could be plugged relatively easily into the aft end of the Atlas 5.

But ULA President and Chief Executive Tory Bruno said making the changes to the Atlas 5’s design to accommodate the AR1 — two of these single-nozzle engines would be needed to replace the double-nozzled RD-180 — could cost up to $200 million.

Van Kleeck said the figure could be significantly less, depending on the particular vehicle configuration.

In a brief interview following the hearing, Rogers expressed surprise at the ULA estimate for integrating the AR1 into the Atlas 5.

“That wasn’t on our radar screen until a day ago,” he said.

Meanwhile, Frank Culbertson, president of the Space Systems Group at Dulles, Virginia-based Orbital ATK said the company responded to the Air Force solicitation with concepts for both liquid- and solid-fueled rockets.

Jeffrey Thornburg, senior director of propulsion technology at Hawthorne, California-based SpaceX, told the subcommittee the company is open to selling its Merlin engines to industry and government. Currently nine such engines power the main stage of SpaceX’s Falcon 9 rocket, which recently earned Air Force certification to launch military payloads.

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.