Russia’s deputy prime minister Dmitry Rogozin has announced that the country will reject a U.S. request to use the International Space Station after 2020. Kremlin is taking these steps as a retaliation against sanctions being imposed by the U.S. over the Ukraine crisis. Just last month NASA announced in a memo sent to employees that it was cutting all ties with Russia except for on the ISS. It cited “Russia’s ongoing violation of Ukraine’s sovereignty and territorial integrity” as the main reason.

The $100 billion International Space Station was a joint effort launched back in 1998. It was planned to operate until 2017 but the mission was extended by the Obama administration through 2024. Since NASA decommissioned its shuttle program in 2011 the only way U.S. astronauts can get a ride to the space station now is courtesy of the Russians, who get $60 million per person for the favor.

Rogozin also claimed that Russia is planning “strategic changes” in its space industry after 2020, even suggesting that they can continue to use the station without the United States. “The Russian segment can exist independently from the American one. The U.S. one cannot,” he said.

Russia is also going to bar the U.S. from buying its rocket engines which would be used to launch military satellites. Rogozin said that they’re ready to deliver the NK-33 and RD-180 engines if the U.S. guarantees they won’t be used to launch military satellites.

The country is evidently following through from the threats made last month. At the time the deputy prime minister joked that the U.S. would have to explore the option of using trampolines to send its astronauts to the ISS. Though with NASA’s new plans of returning human spaceflight to American soil by 2017, it may never come to that.

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