Their relationship on Earth may be at its lowest ebb in decades, but the US and Russia haven't allowed their disagreements over Ukraine get in the way of their joint mission in space.
In the early hours of Wednesday local time, a rocket carrying a Russian-American crew to the International Space Station blasted off successfully from the Baikonur cosmodrome in Kazakhstan.
The Soyuz booster rocket lifted off as scheduled at 3.17 am local time on Wednesday (10.17am NZ time), lighting up the night skies over the steppe with a giant fiery tail. It entered a designated orbit in about 10 minutes after the launch. All onboard systems were working flawlessly, and the crew was feeling fine.
The crew - Nasa astronaut Steve Swanson and Russians Alexander Skvortsov and Oleg Artemyev - are set to dock the Soyuz TMA-12M spacecraft at the station less than six hours after the launch and are scheduled to stay in orbit for six months.
Swanson is a veteran of two US space shuttle missions, and Skvortsov spent six months at the space outpost in 2010. Artemyev is on his first flight to space.
So far, the tensions between the US and Russia over Ukraine have been kept at bay. Since the retirement of the US shuttle fleet in 2011, Nasa has relied on Russian Soyuz spacecraft as the only means to ferry crew to the orbiting outpost and back.
The US pays Russia nearly US$71 million per seat to fly astronauts to the space lab through 2017. It's doing that at a time when it has led calls for sanctions on Russia over its annexation of Crimea from Ukraine following a hastily-arranged referendum. So far the sanctions have been limited and not to the wider Russian economy.
Earlier this month, Nasa Administrator Charles Bolden repeatedly said the conflict in Ukraine would have no effect on what's going on in space between the US and Russia, saying that the "partnership in space remains intact and normal."
He said there's a long history of countries cooperating in orbit, while clashing on terra firma, which is why he said some people have nominated the 16-nation International Space Station for the Nobel Peace Prize.
At the same time, Bolden said on his blog Tuesday that while Nasa continues to cooperate successfully with Russia, it wants to quickly get its own capacity to launch crews. Nasa is trying to speed up private American companies' efforts to launch crew to orbit, but it needs extra funding to do so.
"But even as the 'space race' has evolved over the past 50 years from competition to collaboration with Russia, Nasa is rightfully focused now more than ever on returning our astronauts to space aboard American rockets - launched from US soil - as soon as possible," he said.
Nasa spokesman David Weaver said "Nasa is working aggressively to return human spaceflight launch to American soil, and end our sole reliance on Russia to get into space." He added that later this year the agency plans to select the American companies that will transport its astronauts to the space station beginning in 2017.
The arriving trio will be greeted by Japan's Koichi Wakata, Nasa's Rick Mastracchio and Russia's Mikhail Tyurin, who have been at the station since November. Wakata is the first Japanese astronaut to lead the station.
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