The International Space Station depends on a mix of U.S. and Russian parts.

NASA

Tensions between the U.S. and Russia are high.

President Biden calls Putin a war criminal for making false claims about the U.S. working with Nazis in Ukraine.

The International Space Station is controlled by both Russia and the US, but the tone is very different: American astronauts live side-by-side with Russian cosmonauts, they check in with mission control centers in both countries, and supplies arrive aboard Russian and U.S. spaceships alike.

Nelson said at a Senate hearing that he sees nothing that has interrupted the professional relationship.

Some experts worry that the long-standing relationship may come to an end as the station nears the end of its lifespan.

Scott Kelly, a former astronaut who lived with Russian cosmonauts for nearly a year, hopes that we can hold it together as long as possible.

He says that NASA should prepare for the possibility that Russia might end its participation.

A longstanding partnership starts to unravel

The space station has floated above the politics of planet earth for 23 years as a symbol of unity.

It started as a U.S.-Russian project in 1998, when it seemed possible that the two foes could make a new start. The station was designed so that Russia and the U.S. needed each other to survive.

Mariel Borowitz is an associate professor at the Sam Nunn School of International Affairs at the Georgia Institute of Technology. During a time when Russia faced political and economic instability, the joint program kept Russian rocket scientists employed.

NASA was able to save money by relying solely on Russia systems.

The interdependency grew stronger in 2011. The space shuttle carried astronauts and supplies to the station. Without the shuttle, the space agency relied on Russia's space program to get its astronauts to the station. Kelly says the Russian program can put humans into space and bring them home.

The U.S. used to rely on Russia to get its astronauts to the space station.

NASA/Bill Ingalls/(NASA/Bill Ingalls)

The U.S. may have needed a ride, but they also had a lot of money.

NASA paid billions for seats on the Soyuz rocket, which helped keep the Russian space program afloat.

Even though wars, assassination attempts and allegations of political meddling have not been enough to send the space station off course, the symbiotic relationship has remained. A mix of technical and political factors is changing the collaboration.

The use of Russian rockets was ended in 2020 with the start of transportation by the company, SpaceX.

At the time, the end of that vital tie was a big deal, but it pales in comparison to Russia invading Ukraine. The war has strained relations between the U.S. and Russia, and it has already broken a long-standing Russian collaboration with the European Space Agency.

Tomas Hrozensky, a research fellow at the European Space Policy Institute in Vienna, Austria, says that there was ongoing cooperation between Europe and Russia. Russia has been kicked out of the lunar program by the European Space Agency because it was going to go to space on a Russian rocket.

As a consequence of the war in Ukraine, the member states of the European Space Agency have put significant sanctions on Russia. He conceded that the decision to suspend the rover mission was painful.

Could Russia ditch space station?

The war has made Russia less interested in Western collaboration.

In response to European sanctions, the country suspended the launches of the Soyuz rocket. The head of Russia's space agency, a prickly politician named Dmitry Rogozin, said last month that Russia may pull out of the space station.

The decision has been made, and we don't have to talk about it publicly. I can only say that we will notify our partners a year in advance about the end of our work on the International Space Station.

Anatoly Zak, publisher of Russianspaceweb.com, says that the Russian components are certified to operate until 2024, which is when NASA would like to keep the station running.

Zak and Borowitz are not sure how seriously to take the threats of withdrawal. Borowitz notes that he has made similar statements in the past, but without the space station, they are going to be in a situation where their cosmonauts don't have a clear mission.

It would be very costly for Russia to not have human spaceflight. The space program has a large role in Russian propaganda.

On a recent space walk, a Soviet-era victory banner was unfurled. The banner used to mark Victory Day in Russia has also been used by Russian forces in Ukraine.

Screenshot by NPR/Roscosmos Youtube

The station has played a part in Russia's propaganda efforts.

The Russian part of the station has begun to display Soviet-era items. On a space walk in April, two cosmonauts unfurled a Soviet victory banner to celebrate the defeat of Nazi Germany in 1945. The banner has been flown by Russian forces.

Scott Kelly is a NASA Astronaut and he says that the U.S. should start thinking about how to keep the station running.

Kelly supports continuing to work together in space for the time being.

He says his views may change as the war continues and the allegations of atrocities grow.