In light of what it is calling the "illegal" sanctions that have been imposed on Russia over the Ukraine invasion, Russia has announced it will end cooperation with the US and Western countries on the International Space Station (ISS).

After previously declaring these sanctions an act of "economic war", the Russian government said it would refuse to participate in joint activity with the European Space Agency and NASA, with Roscosmos head Dmitry Rogozin stating the only way they can resume being the “full and unconditional removal of illegal sanctions.” 

Rogozin had previously filed an appeal with NASA and other space agencies, demanding an immediate withdrawal of sanctions by March 31 or ISS cooperation would come to an end. After receiving responses refusing to do so, Rogozin announced the international partnership will no longer continue in a long Twitter thread on April 2. 

“Nevertheless, the position of our partners is clear: the sanctions will not be lifted. At the same time, fearing the destruction of cooperation on the ISS, where the role of Russia is of fundamental importance, to ensure the viability and safety of the station, Western partners make it clear that in reality, sanctions in terms of work in the interests of the ISS will not work,” Rogozin wrote. 

“I believe that the restoration of normal relations between partners in the International Space Station and other joint projects is possible only with the complete and unconditional lifting of illegal sanctions.” 

Rogozin and Roscosmos have been threatening a host of highly controversial actions following the introduction of sanctions after Russia's invasion of Ukraine on February 24, including a strange and veiled video released by Rogozin showing Russia leaving the ISS and it breaking apart, leaving behind US astronaut Mark Vande Hei. This led to wild speculation that Russia was contemplating leaving behind the astronaut, who was scheduled to return home on a Russian Soyuz rocket, as a response to sanctions, but they subsequently announced this was not the case and Vende Hei returned on March 30 after a record-breaking time in space. 

The end of cooperation with Russia may spell the end of the ISS, at least as we know it, with Russian rockets providing integral thrust to keep the ISS in orbit. Following the early waves of sanctions, Rogozin tweeted that the removal of Russia would spell "doom" for the ISS, asking “who would save the ISS from falling out of orbit” onto the USA or Europe. Elon Musk then replied to the tweet with the SpaceX logo and later confirmed the firm would be willing to step in with its Dragon rockets to provide support if needed. 

NASA has already put forward extending the ISS through 2030, with the majority of other partners set to agree. The ISS is governed by the Intergovernmental Agreement, first negotiated by the US, Russia, Europe, Canada, and Japan in 1988. Due to not wanting to violate the IGA, it's unlikely NASA, ESA, Jaxa, and the Canadian Space Agency will break this partnership, so it will in effect come down to Russia. However, Rogozin has blustered and threatened to leave before. Whether it actually happens this time remains to be seen.