The book centres around chronicling the lives of the future Mars mission astronauts, NASA and contractor personnel all involved in making the mission become a reality, and the shifts within NASA's astronaut and management hierarchy throughout the mission's preparations, including female geologist Natalie York's quest to become an astronaut, and her stormy relationships with fellow astronaut Ben Priest and NERVA engineer Mike Conlig. Other astronauts include Ralph Gershon, a former fighter-bomber pilot involved in illegal bombing missions in Cambodia during the Vietnam War whose dream is to be the first black man in space, and Phil Stone, a veteran Air Force test pilot-turned-astronaut who has flown in a long-term stay on a lunar orbital station before the Mars mission.