Update: NASA’s administrator has told a news conference that everything is cool with Russia. The Russians have yet to comment.

There are only two countries in the world today with the capability to send humans into space — Russia and China.

The United States lost that capability on 21 July 2011 when the Space Shuttle Atlantis was retired. The space shuttles had been ferrying astronauts to and from our planet since 1981. Today, the USA relies solely on Russia’s Soyuz craft to get NASA astronauts to and from the International Space Station.

That puts the United States in a precarious position. Despite widespread international condemnation, the Russian army has occupied the Crimean peninsula and looks set to stay for the forseeable future. US president Obama has called this a breach of international law. Tensions are high between the two countries.

Three hundred and seventy kilometres above, looking down on the conflict, the NASA astronauts on the International Space Station, Michael Hopkins and Rick Mastracchio, must be getting a little worried. Their flight home is dependent on Russia and the United States getting along, and their commander, Oleg Kotov, is from the Crimea.

Russia’s Soyuz craft are being used to transport US astronauts to and from the International Space Station // NASA

The schedule of ISS flights is set years in advance. On 25 March 2014, Soyuz TMA-12M is scheduled to launch carrying two Russian cosmonauts and a third NASA astronaut — Steve Swanson.

In May 2014, Hopkins is scheduled to return on the Soyuz TMA-11M. The question is what happens if relations between the two countries continue to deteriorate. Could the astronauts be stranded as prisoners of war?

Let’s be clear — all-out conflict between the United States and Russia is a virtual impossibility at this stage. However, Russia’s president, Vladimir Putin, has been known in the past to use all the leverage available to him to pressure his opponents into submission. It’s not inconceivable that the International Space Station may play some part in this — either by denying the US the use of Soyuz, or simply by charging exorbitant amounts for it.

It’s not like the US wasn’t warned this might become a possibility. In 2008, when Russia marched into its tiny neighbour Georgia and the space shuttles were on the verge of retirement, US senator Bill Nelson warned that the country’s space program would be severely limited without the capability to transport astronauts into space.

What’s more, the United States has a law — the Iran North Korea Syria Nonproliferation Act — that prohibits the country from buying space-related goods and services from Russia while the nation exports nuclear technology to Iran. Nasa was granted a waiver to this law in 2005, and this was extended in 2009, but expires again in 2016.

Depending on how long the conflict goes on for, that could become another problem. In 2008, following Russia’s incursion into Georgia, Nelson said: “It was a tough sell before, but it was doable simply because we didn’t have a choice. We don’t want to deny ourselves access to the space station, the very place we have built and paid. It’s going to be a tougher sell now.”

The SpaceX Dragon capsule could eventually help US astronauts get back into space // NASA

The light at the end of the tunnel is NASA’s Commercial Crew Program — which is funding several American companies to build manned spacecraft. The most famous is SpaceX’s Dragon capsule, which has successfully docked with the International Space Station but isn’t yet ready for manned flight. If the conflict drags on, it’s likely that funds will be pumped into the program and development on the Dragon capsule, as well as other manned spacecraft, will be significantly accelerated.

But that won’t bear fruit until at best 2016, and there are multiple European and American astronauts that are scheduled to make the trip on ten different Soyuz launches until then.

One man who knows what it’s like to be stranded in orbit is Sergey Krikalev. He was launched to the Mir space station in 1991 by the Soviet Union, which promptly collapsed. He circled the Earth for ten months while his country fought off a coup, changed leaders, and then was dissolved entirely. He eventually returned to solid ground after 313 days in orbit, and today holds the record for the most time spent in space. His story was told in a 1999 documentary titled Out Of The Present.

An excerpt from the documentary ‘Out Of The Present’

The movie 2010, based on Arthur C Clarke’s literary sequel to 2001: A Space Odyssey, also considers the fate of two crews of astronauts in space following a conflict between the United States and the Soviet Union.

Movies aside, ultimately the fate of the American astronauts on board the International Space Station will depend on the duration and the severity of the US-Russia conflict. If matters are resolved reasonably quickly, as they were in the 2008 Russo-Georgian war, then the space program should emerge relatively unscatched.

If the crisis deepens and drags on, it’s likely that the US astronauts will be brought back to Earth and repatriated by the Russians, while science work is halted and the station operates on a skeleton crew. It’s extremely unlikely that the astronauts would be held against their will on the station.

Eventually, talks may need to be held on the future of the International Space Station project, perhaps with China being brought on as an additional partner ahead of the recommencement of US manned spaceflight. The country has previously expressed interest in space partnerships, though noted its desire not to fall into an “unequal” relationship with Washington.

Whatever happens, an increasingly belligerent Russia is only bad news for international space cooperation.