During his career at NASA, Swanson logged over 195 days in space, undertaking five spacewalks. His three missions to the ISS include two Space Shuttle flights (STS-117 and STS-119) and one Soyuz flight (TMA-12M).
How does NASA select astronauts?
Nobody knows for sure. Really it’s up to the chief of the astronaut office to make that selection, and sometimes others