A U.S. defense firm is accelerating deliveries of rocket engines from Russia as members of Congress seek to end contracts with the country over the conflict in Ukraine.
United Launch Alliance said Thursday it is speeding up its schedule for receiving Russian-made engines, from once a year to twice per year.
ULA received one shipment of four engines last November, but this year will receive shipments of two engines in August and three engines in October.
"This year we are having the engines shipped once they are completed versus waiting to get one shipment," ULA spokeswoman Jessica Rye told The Hill.
The Air Force has a five-year contract with ULA to buy 36 rocket cores, for both Atlas V rockets, which use the Russian-made engines, and another type of rocket called Delta IV, which does not.
Lawmakers have called upon the administration to stop using rockets with the Russian-made engines, which are manufactured by Russian-owned firm Energomash.
Members of Congress, as well as competing rocket manufacturers, argue that U.S. national security missions are vulnerable to Russia's supplying the engines, and that taxpayer dollars should not go towards bolstering Russia.
Each engine reportedly costs between $11 to $15 million.
ULA pushed back against those concerns, saying that Russia has taken no actions to restrict sales or exports of the RD-180 engines, and if it did, ULA would use its Delta IV rockets, which don't rely on Russian engines.
"The RD-180 supply chain has never experienced a supply disruption in the 15 years of imports and is widely considered throughout the aerospace industry as a model of international cooperation," Rye said.
She said restricting imports of the engines would have a minor effect on Russia, because 90 percent of Russian exports to the U.S. are raw materials.
"It imposes an artificial crisis in the U.S. domestic launch market, one that only serves to impede U.S. capabilities to launch critical payloads," she said.
"It is completely appropriate to review the status of supply of RD-180s in light of the current political tensions in Russia," she said. "However, ULA is currently the only certified launch provider that can support the full range of national security space missions."