Even if up for 8 months – and returning to a US with a different President, perhaps even a different party-of-the-President, they'll not match the experience of Sergei Krikalev – who traveled to the space station Mir for the USSR, & was for a while stuck there when the USSR dissolved, only returning 311 days later:

https://en.wikipedia.org/wiki/Sergei_Krikalev

He later became the 1st cosmonaut to fly on the US Space Shuttle:

https://historycollection.jsc.nasa.gov/history/shuttle-mir/p...