7. Valeri Polyakov: Record Loneliness
Valeri Polyakov holds the human spaceflight record for the longest single space mission: 437 days aboard the Mir space station. This extended period led to profound feelings of detachment from Earth and family. Polyakov meticulously documented his mood swings, noting periods of sadness and increased workload during the initial weeks in space and upon return to Earth. These insights have been instrumental in shaping NASA’s behavioral health protocols for long-duration missions. (space.com)