Russia cast doubt on the long-term future of the International Space Station, a showcase of post-Cold War cooperation, as it retaliated on Tuesday against U.S. sanctions over Ukraine.
Deputy Prime Minister Dmitry Rogozin said Moscow would reject a U.S. request to prolong the orbiting station's use beyond 2020. It will also bar Washington from using Russian-made rocket engines to launch military satellites.
Moscow took the action, which also included suspending operation of GPS satellite navigation system sites on its territory from June, in response to U.S. plans to deny export licences for high-technology items that could help the Russian military.
"We are very concerned about continuing to develop high-tech projects with such an unreliable partner as the United States, which politicises everything," Rogozin told a news conference.
Washington wants to keep the $100 billion, 15 nation space station project in use until at least 2024, four years beyond the previous target.
Moscow's plan to part ways on a project which was supposed to end the "space race" underlines how relations between the former Cold War rivals have deteriorated since Russia annexed Ukraine's Crimea region in March.
Since the end of the U.S. Space Shuttle project, Russian Soyuz spacecraft have been the only way astronauts can get to the space station, whose crews include mostly Americans and Russians, as well as visitors from other countries.
At a time when Moscow is struggling to reform its accident-plagued space programme, Rogozin said U.S. plans to deny export licences for some high-technology items were a blow to Russian industry. "These sanctions are out of place and inappropriate," Rogozin said. "We have enough of our own problems."
Moscow's response would affect NK-33 and RD-180 engines which Russia supplies to the United States, Rogozin said. "We are ready to deliver these engines but on one condition that they will not be used to launch military satellites," he said.
RD-180 engines are used to boost Atlas 5 rockets manufactured by United Launch Alliance (ULA), a partnership of Lockheed Martin and Boeing that holds a virtual monopoly on launching U.S. military satellites.
ULA on Tuesday said it was not yet aware of any restrictions and hopes talks will resolve any issues that do arise. It added that it can use other launch vehicles and has a two-year supply of engines to smooth over any transition.
"ULA and our Department of Defense customers have always prepared contingency plans in the event of a supply disruption," ULA spokeswoman Jessica Rye said