United Launch Alliance (ULA) ordered 20 Russian-developed RD-180s for use in civil and commercial missions with annual deliveries beginning in 2017, according to a company statement issued December.

The company said it is moving “smartly” with engine partners Blue Origin and backup Aerojet Rocketdyne [AJRD], but added this development program is difficult and takes years to complete. ULA said this bridge contract for 20 RD-180s will allow it to provide reliable and affordable launch services for civil and commercial customers while the new American engine is developed. The Air Force and industry are working toward a congressional mandate to be off the RD-180 for national security launches by 2019.

ULA spokeswoman Jessica Rye said Jan. 5 the company receives RD-180s on an annual basis and will receive three engines in late 2017.

The timing of the announcement came shortly after ULA won a big victory with the fiscal year 2016 Consolidated Appropriations Act, which lifted caps that severely restricted Air Force use of the engine in national security launches. The bill did not lift the mandate to get the Defense Department off the engine by 2019.

James Muncy, founder of independent space policy consultancy PoliSpace, said Jan. 5 the timing was simply a coincidence.

“It makes sense that all of these engines are for civil or commercial customers. It probably took them months to negotiate this deal,” Muncy said. “I don’t think a week between the omnibus (spending bill) and a contract announcement is enough time to negotiate a change to buy more engines for DoD use.”

The RD-180 is developed by NPO Energomash. ULA is a joint venture of Lockheed Martin [LMT] and Boeing [BA].