Russian cosmonauts board Space Station wearing blue and yellow, the colors of Ukraine

Three Russian cosmonauts boarded the International Space Station wearing yellow and blue, in an apparent statement of support for Ukraine.

Wearing the colors of the Ukrainian flag has widely been seen as a way to oppose Russia's invasion of Ukraine.

The three cosmonauts, Oleg Artemyev, Denis Matveev and Sergey Korsakov, docked their Soyuz MS-21 spacecraft on Friday. The mission is planned for six months.

In a livestream of the docking, Artemyev was seen wearing an entirely blue spacesuit before entering the ISS. When they entered through the hatch, all three were wearing yellow spacesuits with blue. The Russian flag was also featured on their spacesuits.

It's not yet clear what message the cosmonauts were trying to send. But when asked about the yellow suits, Artemyev said that every crew chooses their own.

"It became our turn to pick a color. But in fact, we had accumulated a lot of yellow material so we needed to use it. So that's why we had to wear yellow," he said, according to the Associated Press.

In the last weeks since Russia's invasion of Ukraine, there have been concerns over space relations between the U.S. and Russia. While geopolitical tensions on Earth have remained somewhat separate from how the U.S. and Russia work together on space endeavors, some officials have said the recent conflict is much different than past tensions.

The three Russians join two other Russians who were already aboard the ISS, along with four Americans and one German astronaut.

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