Lieutenant General Samuel A. Greaves Credit: U.S. Air Force

WASHINGTON — The U.S. Air Force issued a solicitation June 2 for an American-made rocket propulsion system to help end reliance on the Russian-built rocket engine used today to launch most national security payloads.

The solicitation calls for industry to move quickly to develop prototypes of new launch 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 booster propulsion technologies.

Congress mandated last year that the Defense Department develop a domestic propulsion system that would enable the Air Force by 2019 to end its reliance on the Russian-made RD-180 rocket engine that powers United Launch Alliance’s Atlas 5 rocket.

While Air Force officials have raised doubts they can meet that deadline, service leaders have nonetheless been working for months on developing and kicking off an acquisition strategy. That four-step strategy, first announced in April and fleshed out June 2, calls for investing in promising technologies and culminates with a rocket propulsion system to help assure the Air Force has at least two commercial providers to launch military and spy satellites to space.

“We’re not sitting around. We’re moving out fast,” said Lt. Gen. Samuel Greaves, commander of the Space and Missile Systems Center at Los Angeles Air Force Base, during a conference call with reporters. “This is not something we’re approaching with a relaxed strategy. This is almost [an] Apollo, [a] getting to the moon approach.”

U.S. Lawmakers, particularly members of the Senate Armed Services Committee, have criticized the Air Force for being slow to spend the nearly $260 million Congress allocated for a new engine.

The pair of announcements June 2 formally kicked off the service’s acquisition strategy.

Thus far, the Air Force has already spent about $57 million for work that includes upgrading rocket engine test stands and large scale engine combustion tests, according to service officials.

The first steps builds on that effort as the service looks to improve its understanding of booster propulsion technologies.

The Air Force is looking for improvements in two specific areas: reducing the cost of booster propulsion components and subsystems through the use of new materials and additive manufacturing; and improving the performance, safety and cost for new or existing launch systems. The service is looking for improvements which can be completed in less than two years.

For this step, the Air Force plans to award six to eight contracts with a combined value of $32 million for companies to work on booster propulsion technologies. The individual contract awards will range between $500,000 and $8 million, the notice said. Companies will be eligible for multiple awards so long at the total value does not exceed $16 million.

The Air Force plans to ask industry to submit white papers in specific areas, but it is not clear how quickly the service would makes contract awards for the proposals it wants to fund.

At the same time, the Air Force is looking for responses from industry for the second step in the strategy. During this step, the Air Force plans to begin partnerships with industry on prototype rocket propulsion systems. Those systems could include main- or upper-stage engines, the June 2 solicitation said, as a way to end dependence on the RD-180.

Greaves said industry would be expected to cover at least one-third of the costs in this step of the process, but the actual size of the government investment would vary from proposal to proposal.

The Air Force’s contribution would cover 12 to 18 months of development work, Greaves said, and last until a preliminary design review.  T.

Initial proposals are due by June 23. The Space and Missile Systems Center, the Air Force’s space acquisition arm, would begin making rolling awards as early as September and running through December, he said.

In the third step of the strategy, the Air Force would build on the progress made during the second step by making a shared investment with industry in launch system development. This step may incorporate some of the improved propulsion technology from the first step, Greaves said.

In the final step, if all goes to plan, the service will have fostered a launch system that could compete for national security missions around 2018.

“What we’re doing is taking a major step in pursuing assured access to space for the nation within a competitive environment by pursuing a launch service approach,” Greaves said.

Meanwhile, Greaves also said SMC and the Pentagon are involved in “intense” discussions over the potential continued use of the RD-180 engine under a waiver from the defense secretary. Such a waiver is allowed under the 2015 National Defense Authorization Act.

The use of the waiver would allow United Launch Alliance to compete for more than five launch contracts from 2015 to 2019. Without an intervention from Congress or the use of the wavier, ULA has said it would not have enough engines to compete against SpaceX for launch contracts until ULA’s new Vulcan rocket is ready around 2022.

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.