(CNN) — Russia is threatening to end its space program partnership with the U.S. amid growing tensions over the crisis in Ukraine.
They were all smiles in the International Space Station this week, but could this be one of the last times that American astronauts and Russian cosmonauts journey together through space?
Russian officials are taking the battle over Ukraine into orbit, vowing to abandon the space station four years early in 2020.
And banning Russian-made rocket engines to launch U.S. military satellites. The deputy prime minister even suggested astronauts instead use a trampoline.
This is no small problem because since NASA retired the shuttle in 2011, American astronauts have no other way up or down than hitching rides on Russian rockets.
“The Russian announcement really means we need to rethink our reliance on them because it shows we are dependent on them in ways that might have made sense ten years ago but doesn’t make sense anymore,” Jim Lewis, Center for Strategic and International Studies said.
The U.S.-Russian space partnership has thrived for decades, one of the most visible symbols of detente during the Cold War and the new peace after the fall of the Soviet Union.
And it was very much a win-win: The U.S. saved billions on the shuttle. Russian made billions as a high-tech taxi service.
U.S. officials express hope the Russian threat is just bluster.
“We’ve had a long cooperation on our space program with the Russians and we’re hopeful that will continue. We still continue to cooperate on a range of issues,” Jen Psaki, State Dept. Spokesperson said.
NASA issued a statement: “We have not received any official notification from the government of Russia on any changes in our space cooperation at this point.”