MOSCOW - A Russian and an American returned to Earth on Wednesday with their Japanese commander aboard a Soyuz capsule in the first such landing since Moscow's ties with the West imploded over Ukraine.
Koichi Wakata -- the first Japanese leader of an International Space Station mission -- NASA's Rick Mastracchio and Russian cosmonaut Mikhail Tyurin completed a 188-day stay that began months before Europe was thrown into its worst security crisis since the Cold War.
Ex-Soviet Ukraine has since seen a part of its territory seized by Kremlin forces and the West retaliate with sanctions that have prompted Russia -- provider of the sole manned link to the orbiting laboratory -- to question the wisdom of future cooperation in space.
A top Russian minister stepped up the rhetoric on Tuesday by warning that Moscow may reject Washington's request to extend the station's lifespan by four years until 2024.
The trio was all smiles on Wednesday as they clambered out of the conic capsule in their bulky space suits after touching down without mishap in the sand-swept steppe of Kazakhstan.
But Tyurin hinted of the overriding tensions by singing the praises of Russian space equipment that may one day slip out of Western hands.
"The landing was outstanding," Tyurin said in comments broadcast on Russian state television.
"It was simply ideal. We do have some wonderful technology!"
US 'hopeful' about cooperation
Moscow is fiercely proud of its rockets and still fetes its ability to trump the United States during the Soviet-era space race by putting the first man in orbit in 1961.
And a top minister in charge of the military-industrial complex warned that Moscow may strike back at new high-technology export restrictions that Washington imposed in retaliation at the Kremlin's Ukrainian land grab by limiting US access to Russian space equipment.
(Left to right): Japanese astronaut Koichi Wakata, Russian cosmonaut Mikhail Tyurin and US astronaut Rick Mastracchio, pose for a photo during a welcome ceremony at the airport in Karaganda, Kazakhstan. PHOTO/AFP/POOL
Deputy Prime Minister Dmitry Rogozin said that Russia was "planning to only need the ISS until 2020" and then spend funding "on other promising space projects."
NASA had said in January it would like the orbiter's lifespan extended in order to improve its marketability and chances of getting commercial investment in space.
The US government agency said only that it had "not received any official notification from the government of Russia on any changes in our space cooperation at this point."
But State Department spokeswoman Jen Psaki suggested that the United States might not be as reliant on Russia's space technology as some in Moscow might like to think.
"We do have a number of materials of the same kind that we can use in the future," she said.
Rogozin added on Tuesday that Moscow could also prohibit the United States from using a Russian engine crucial to some Pentagon launches of its military satellites.
Space expert Vadim Lukashevich of Moscow's state-funded Skolkovo Foundation said the absence of Russia's RD-180 engines could ground the US Defence Department Atlas V rocket for "two to three years".
Yet Lukashevich noted that the RD-180 deal requires Russia to also disclose to the United States all the details of the engine's design.
"So in three years, they will be able to develop their own engine and we will lose that market for good," Lukashevich said in a telephone interview.
NASA hopes to keep the ISS spinning 400 kilometres (250 miles) above Earth a bit longer to help private US firms such as SpaceX upgrade rockets it now uses to ferry up cargo to also be able to accomodate astronauts.
The United States has relied on the Soyuz for all manned missions since retiring its Shuttle Programme in 2011.