to support United States Government launches, as well as commercial launches, it was also arranged for the RD-180 to be co-produced by Pratt & Whitney. However, all production to date has taken place in Russia. The engine is currently sold by a joint venture between the Russian developer and producer of the engine NPO Energomash and Pratt & Whitney, called RD Amross. The RD-180 was first deployed on the Atlas IIA-R vehicle, which was the Atlas IIA vehicle with the Russian (hence the R) engine replacing the previous main engine. This vehicle was later renamed the Atlas III. An additional development program was undertaken to certify the engine for use on the modular Common Core Booster primary stage of the Atlas V rocket. Prospective uses RD-180 was proposed to be used with a new family of Rus-M Russian space launch vehicles, proposed by Roskosmos contractors, but the program was canceled by the Russian Space Agency in October 2011. In March 2010, Jerry Grey, a consultant to the American Institute of Aeronautics and Astronautics and Universities Space Research Association and a former professor of aerospace engineering at Princeton University, suggested using the RD-180 for a prospective NASA heavy-lift launch vehicle. For those who might be concerned about too much reliance on Russia, he pointed out that RD Amross was "very close to producing a U.S.-built version of the RD-180, and with some infusion of NASA funding could be manufacturing that engine (and perhaps even a thrust equivalent of the RD-170) in a few years". Prospective alternative In February 2010, despite the availability of necessary documentation and legal rights for producing RD-180 in the United States, NASA was considering development of an indigenous core-stage engine that would be "capable of generating high levels of thrust approximately equal to or exceeding the performance of the Russian-built engine". NASA desired to produce a fully operational engine by 2020 or sooner, depending on partnership with the U.S. Defense Department. In 2021, NASA stopped buying new engines due to the planned retirement of Atlas V rocket. 2022 Russian invasion of Ukraine On February 24, 2022, Russia began a large-scale military invasion of Ukraine. Six days later on March 2, 2022, as Russia continued the invasion, they formally announced an end of all sales and support of the RD-180 engines to the United States, in retaliation for sanctions placed on Russia by the US for the Ukraine