WASHINGTON — United Launch Alliance (ULA), which operates the embattled Atlas V, has enough of the rocket’s Russian engines in storage to meet its commitment to the U.S. Air Force in the company’s 36-booster bulk buy inked in December, according to a Boeing executive.

"We believe we can deliver on the block buy with the engines we have," says Roger Krone, president of Boeing Network and Space Systems. ULA has 16 RD-180s on U.S. soil, according to an industry official.

Krone was asked about the stockpile during a May 13 roundtable with reporters, shortly after Dmitry Rogozin, Russia’s deputy prime minister, announced Moscow would halt further sales of the RD-180 for military launches and truncate International Space Station participation beyond 2020. His announcement was a response to sanctions posed by the U.S. and allies — targeting specific Kremlin officials, including Rogozin — after Russia annexed Crimea and began stirring rebels in Ukraine.

Krone and ULA say they have received no official notification of a stoppage from NPO Energomash, the Russian RD-180 manufacturer, or RD Amross (a joint venture including Aerojet Rocketdyne crafted solely to sell the engines in the U.S.), of a work stoppage on domestic orders.

Boeing and Lockheed Martin share a 50/50 financial stake in ULA since the two merged their launch operations in 2006. He says the company’s assumption going into the block buy was a roughly even split between Delta IV (a legacy Boeing vehicle) and Atlas V (a legacy Lockheed Martin vehicle) cores. ULA has said it maintains a two-year stockpile in the U.S. in accordance with the policy crafted when Lockheed received approval to source its propulsion system from NPO Energomash.

Should it run short of RD-180s, ULA and U.S. Air Force, its customer, can shift some launches from the Atlas V manifest to Delta IV. "That is not our desired approach," Krone says. "We’d just as soon not move the manifest."

The Atlas V and Delta IV, designed under the Air Force’s Evolved Expendable Launch Vehicle (EELV) program, were crafted with enough commonality to allow for satellites to fly off either model. But despite their similarities, each does have peculiar requirements – and integration costs – for a particular satellite model. Krone says integration on both boosters has already been done for the GPS IIF – seven remain to be launched – and Wideband Global Satcom – at least four remain to be launched.

The fate of the Atlas V was suddenly questioned due to tensions between Moscow and Washington. Fanning the flames is a suit filed in Federal Claims Court by Space Exploration Technologies (SpaceX) April 28. The company, founded by entrepreneur Elon Musk, claims the Air Force’s 36-core deal with ULA bypassed traditional competition rules, resulting in a buy that is needlessly costly and monopolistic.

In reviewing SpaceX’s claim and the sanction rules, the court placed a temporary injunction on payments from ULA to RD Amross for the RD-180s. However, it was lifted May 9, and payments resumed May 13, ULA spokeswoman Jessica Rye says. "There is no impact to ULA’s factory or launch operations," she says.