Project Hail Mary is first and foremost a survival narrative. Faced with extraordinary challenges in his environment and also within his own mind via amnesia, Grace spends nearly every scene of the book fighting to save his own life, Rocky’s life, or all of humanity. Weir’s outlook on survival is fairly optimistic, and the novel works from the premise that the motivation to survive is ultimately stronger than the fear of death or hopelessness. The will to survive even supersedes cultural differences on Earth and transcends humans entirely to motivate all forms of life in the galaxy, from Astrophage to Eridians. Weir contrasts the purely biological imperative of Astrophage to survive and breed with the moral imperative to maintain civilization felt by intelligent life. Although they express it differently, all life forms are motivated by a desire to live and thrive.

Grace’s instincts for short-term survival are also placed in direct conflict with the survival of the entire human race, forcing him to decide whose survival is most important, for how long, and at what cost. Grace’s survival and the survival of the human race are inextricable, as he must survive at least long enough to send back the Beetle probes to save Earth, and if Project Hail Mary failed, then he would have most likely died prematurely on Earth.