A Monday story by the Associated Press quotes NASA administrator Charles Bolden as denying that a Russian withdraw from the International Space Station would cause the project to be terminated. He claimed that no one international partner is crucial to the continuation of the ISS. This seems to fly in the face of the judgment of other space experts, not to mention Russia Deputy Prime Minister Dmitry Rogozin, who implied that the Russians would detach its modules from the ISS in 2020. One is a propulsion module without which the space station cannot maintain a stable orbit.
The Houston Chronicle noted that Russia has another trump card to play even before 2020. Since the end of the space shuttle program the international partners have been totally dependent on the Russian Soyuz to access the space station. While space observers think it is unlikely the Russians will kick American astronauts off their spaceship, it is a card they could play at any time. Commercially operated, government funded vehicles that could take astronauts to and from the space station are not slated to be operational before 2017.
Bolden has apparently not elaborated on what exactly he means. To be sure, at least for now, the International Space Station will remain flying through 2020. But afterwards, if Russia carries through on its threat, its continued survival remains problematic.
The United States and the other partners could adapt to the Russian departure in a number of ways. It could build replacement modules for the Russian ones that would go away. It could keep the Russian modules on the ISS, perhaps by force. The former solution would cost extra money. The latter would be a bold diplomatic move that might result in the first international crisis in space, something that would not be lightly entered into. In any case, for now, NASA’s official position is to deny that there is a problem.