The ongoing conflict between Russia and the U.S.-led West over the Ukraine crisis seems to be spiraling out into the space with hitherto unforeseen and unexpected impact on international space collaboration that may have serious implications for the future of the International Space Station (ISS).

The U.S. and its allies have imposed a slew of sanctions against Russia over its military action in Ukraine, including new constraints on high-tech exports that U.S. President Joe Biden said were designed to "degrade Russian aerospace industry, including their space program."

Biden's assertions have prompted the head of the Russian space agency Roscosmos, Dmitry Rogozin, to warn that the U.S. move could potentially "destroy our cooperation" on civil space exploration and the ISS, leading to an unpredictable situation where the 500-ton space lab could come crashing down on the US, Europe, China or India.

"Do you want to destroy our cooperation on the ISS?" Rogozin asked as he posted a series of tweets in Russian, warning about the consequence of the U.S. sanctions on Russia's aerospace industry. 

"If you block cooperation with us, who will save the International Space Station (ISS) from an uncontrolled deorbit and fall into the United States or ... Europe?" he asked, pointing out that orbital control of the ISS into a safe altitude is maintained using periodic thrusts from engines of a Russian cargo craft docked to the ISS. 

"There is also the possibility of a 500-ton structure falling on India and China. Do you want to threaten them with such a prospect? The ISS does not fly over Russia, therefore all the risks are yours. Are you ready for them?" implored Rogozin, who has been at the helm of Roscosmos since May 2018.

He implied that if Russia's space sector is pushed out by the U.S. sanctions, there would be no one to correct the space station's orbit and the ISS could face unforeseen consequences. 

The Roscosmos chief also accused the U.S. of trying to monopolize the global space sector by destroying the Russian competition. "Do you want to ban all countries from launching their missions using the most reliable Russian rockets? This is what you are already doing and are planning to finally destroy the world market of space competition from January 1, 2023, by imposing sanctions on our launch vehicles. We are aware," he said in his tweets.

Rogozin described Biden's punitive actions as "Alzheimer's sanctions," urging the U.S. establishment to renounce the restrictions.

Even last June, Rogozin had threatened to withdraw from the ISS unless U.S. sanctions on Russia's space sector were lifted. However, speaking to CNN last September, the Roscosmos chief also asserted that the participating ISS members are "a family, where a divorce within a station is not possible."

NASA: Space cooperation with Russia to continue

In response to the Rogozin's terse warnings, the U.S. space agency NASA issued a statement playing down the concerns over the future of the ISS. The statement asserted that the U.S. space agency was continuing to work with all of its international partners, including Roscosmos, "for the ongoing safe operations of the International Space Station."

"The new export control measures will continue to allow U.S.-Russia civil space operations," NASA added. "No changes are planned to the agency's support for ongoing in-orbit and ground-station operations."

The ISS was launched in 1998 by the Russian and U.S. space agencies with their counterparts from Canada, European Union, Japan and Brazil joining the project later. Ever since, it has been a symbol of post-Cold War international cooperation between former rivals.

For nearly a decade since July 2011, when NASA's Space Shuttle was decommissioned, the U.S. was dependent on Russia's Soyuz spacecraft to launch American astronauts to the ISS. That dependence ended only in November 2020 with the first flight of Space X's Crew Dragon.

The ISS, orbiting some 400 kilometers (250 miles) above Earth, is currently populated by a crew of four Americans, two Russians and a German. The space station is divided into two orbital sections – Russian and American.

"The Russian segment can't function without the electricity on the American side, and the American side can't function without the propulsion systems that are on the Russian side," former NASA astronaut Garrett Reisman told CNN. "So you can't do an amicable divorce. You can't do a conscious uncoupling," he added echoing Rogozin's previous remarks.

Russia has earlier indicated that it could pull out of the ISS in 2025 after Roscosmos' agreement with its international partners runs out in 2024, while hinting that Moscow might already be building a space station of its own. The rapidly evolving geopolitical dynamics between Russia and the U.S. over the next two years will be critical in deciding the fate of the ISS.