Angered over U.S. sanctions against Russian officials involved in the annexation of Crimea, and unrest in Eastern Ukraine, Russian deputy Prime Minister Dmitry Rogozin said Moscow may retaliate by re-assessing the space cooperation between the two countries.

If his threat becomes reality, it could affect future space explorations aboard the International Space Station (ISS).

Russia has not formally committed to continue cooperation on the ISS until 2024, as the U.S. proposes, and now says it might pull out by 2020. But the largest and most important US-Russian space cooperative seems to be unaffected.

Astronaut Rick Mastracchio, who recently returned to earth after more than six months in orbit, says the atmosphere on the space station is as good as ever.

"The working relationship that we have at the person-to-person level both on board the space station and even here on the ground, we get along very well with our Russian colleagues, so there's been no problem whatsoever working with them," he said.

The personal and professional relationships may be intact, but Scott Pace, director of the Space Policy Institute at George Washington University, says the political environment ? and the strategic reasons for continuing cooperation ? have come under pressure.

"The question is, 'Is this a temporary state of affairs or is this more of a permanent watershed state of affairs which would call into question the entire range of post-Soviet cooperation that we have had with Russia?'" he said.

NASA expects to launch the Orion capsule, to carry astronauts to the space station and beyond without Russian involvement, by 2017.

With diminishing public support and ever-shrinking budgets for sending human crews on deep space missions, officials realize that international cooperation is a necessity.

At a recent panel discussion on the future of space explorations at the Berlin Air and Space Show, NASA administrator Charles Bolden said his agency understands that.

"I have to emphasize, there's nothing on this chart that we're doing alone," he said.

For instance, the power and propulsion systems for the Orion capsule are provided by the Europeans, with the bulk of construction being done in Germany. But Russian space officials did not take part in that discussion.

Pace says Moscow wants to return to exploration of the moon, but might not have funds to support that.

"Russia is going to have to make a decision as to what it wants to be really doing in space past 2020," he said.

As Pace sees it, a continued Russia-U.S. partnership would be good for international space cooperation, but that seems to be subject to political forces beyond the space program.

Meanwhile, a fresh U.S.-Russian crew is heading to the ISS this week aboard the Russian-made space capsule Soyuz.

Source: Voice of Amercia