Three Russian cosmonauts launched to the International Space Station on Friday, a normally routine mission to the orbiting outpost that is now taking place against the backdrop of Russia's invasion of Ukraine.
Scrutiny over the liftoff has grown as the conflict in Ukraine has strained relations between Russia and its space station partners, including NASA, and has called into question the future of the iconic orbiting lab.
Cosmonauts Oleg Artemyev, Denis Matveev and Sergey Korsakov launched aboard a Soyuz rocket and capsule at 11:55 a.m. ET from Russia's spaceport, the Baikonur Cosmodrome, in southern Kazakhstan.
The trio is expected to spend roughly six and a half months living and working at the orbiting lab, and will replace three of the seven crew members who are at the space station.
Russian cosmonauts Pyotr Dubrov and Anton Shkaplerov and NASA astronaut Mark Vande Hei are slated to return to Earth in a Soyuz capsule March 30.
The International Space Station is a collaboration among NASA, Russia's Roscosmos space program, the European Space Agency, the Canadian Space Agency and the Japan Aerospace Exploration Agency. Construction of the outpost in low-Earth orbit began in 1998 and was completed in 2011.
Hailed as a civil space victory between two former Cold War adversaries, the more than 20-year legacy of the space station may now be under threat.
Dmitry Rogozin, the director of Roscosmos, has repeatedly lashed out over sanctions imposed on Russia, posting angry tirades on Twitter criticizing the United States and fueling the escalating tensions.
In late February, he condemned what he called "openly hostile" U.S. policy and subsequently threatened the survival of the space station.
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"If you block cooperation with us, who will save the ISS from uncontrolled deorbiting and falling into the United States," he tweeted Feb. 24, according to a translation.
Last week, Rogozin feuded online with retired NASA astronaut Scott Kelly, after Kelly criticized Roscosmos for covering up non-Russian flags on Soyuz rockets that had been purchased for commercial launches.
"Without those flags and the foreign exchange they bring in, your space program won’t be worth a damn," Kelly wrote in Russian. "Maybe you can find a job at McDonald’s if McDonald’s still exists in Russia."
Rogozin responded by hurling insults at Kelly and calling him "defiant" and "destructive."
"Perhaps the dementia and aggression that you have developed is a consequence of the overload and stress of four flights into space," he said in a now-deleted tweet.
In another tweet that was quickly deleted, Rogozin stepped up his threats, saying: "Get off, you moron! Otherwise the death of the #ISS will be on your conscience!"
Tensions reached a boiling point after a Russian state news program shared a video that purported to show Dubrov and Shkaplerov leaving the space station without Vande Hei. The video sparked fears that Russia might maroon Vande Hei, who earlier this week broke the record for the single longest spaceflight by an American explorer, aboard the space station.
A subsequent article published March 14 by the state-run TASS news agency said Vande Hei would return on the Soyuz capsule as planned.
Rogozin's Twitter outbursts are in stark contrast to NASA officials, who have kept a relatively low profile and have insisted that operations in space are continuing as usual.
In a video town hall held Monday, NASA Administrator Bill Nelson said the agency is, "continuing to work with all our international partners to continue safe operation of the ISS," according to a text of his remarks obtained by NBC News.
"We have been meeting almost daily for three weeks to ensure the safe operations of the ISS," Nelson said.