The LSP is a five-year procurement for approximately 34 missions that will blaunch starting in 2022.

WASHINGTON — The Air Force Space and Missile Systems Center on Friday released the final request for proposals for the purpose of competitively awarding contracts in 2020 to two domestic launch service providers. Proposals are due Aug. 1.

The National Security Space Launch Phase 2 Launch Service Procurement (LSP) is the second phase of the program previously known as the Evolved Expendable Launch Vehicle and recently renamed National Security Space Launch. Overseen by the Air Force and the National Reconnaissance Office, the NSSL program will consider both reusable and expendable launch vehicles.

Two vendors will be selected in 2020 from a field that is expected to include current national security launch providers United Launch Alliance and SpaceX, was well as new entrants Blue Origin and Northrop Grumman.

The LSP is a five-year procurement for approximately 34 missions that will launch starting in 2022. One of the winners will get 60 percent, the other 40 percent. The Air Force and the NRO are projected to spend about a billion dollars a year on national security launch services.

The final request for proposals (RFP) is being issued following three rounds of draft RFPs since December. In the weeks leading up to Friday’s release, the launch procurement program was caught in a political fight as congressional supporters of launch providers pushed for the Air Force to make revisions to the competition schedule and the selection criteria. In response to concerns raised by House Armed Services Committee Chairman Adam Smith (D-Wash.), the Air Force delayed the RFP from its original March 29 release date to conduct further reviews and tweak some provisions. Air Force officials insisted that the competition could not be postponed any further due to the timeline set by Congress for the Defense Department to stop using United Launch Alliance’s Atlas 5 rocket whose main stage is powered by the RD-180. By law, DoD will not be allowed to buy Atlas 5 launches after Dec. 31, 2022.

Blue Origin, United Launch Alliance and Northrop Grumman in October were collectively awarded Launch Service Agreement contracts worth $2.3 billion to help partially fund the development of their vehicles and build the infrastructure to launch national security payloads in preparation for the Phase 2 LSP. SpaceX did not win an LSA contract but the Air Force made Phase 2 a “full and open competition” allowing any company to compete for procurement contracts regardless of whether they have an LSA development contract.

“We must move forward now. We are answering Congress’ 2014 directive to transition off the Russian-made RD-180 rocket engine,” Secretary of the Air Force Heather Wilson said in a statement. “The industrial base is ready.”

William Roper, assistant secretary of the Air Force for acquisition, technology, and logistics said the Phase 2 strategy “harnesses the commercial launch industry to meet the more demanding national security space launch needs.”

With the congressional mandate on the RD-180 engine and the planned retirement of ULA’s Delta 4 rocket, the Air Force “developed an acquisition strategy to meet national security space launch requirements for the future,” he said.

The Air Force said the three LSA development awards to Blue Origin, Northrop Grumman and ULA were intended to ensure their respective launch systems — New Glenn, OmegA, and Vulcan Centaur — are able to meet the more stressing national security space requirements. The Air Force did not award SpaceX a development contract but expects the company to compete in Phase 2. SpaceX’s Falcon 9 and Falcon Heavy launch vehicles were competitively awarded nine missions over the last two years.