Also docked to the space station is SpaceX’s Crew Dragon capsule that ferried four astronauts to the ISS in March, and a Russian Soyuz capsule that delivered three others in September. Stich acknowledged that at least one of those vehicles could provide an alternative ride home for Wilmore and Williams.
In the book NASA has a host of issues with a mars mission including an astronaut dying but in the timeline of the book it basically gets sold for parts and privatized.