Project Hail Mary

by Andy Weir

Dr. Ryland Grace, a science teacher, wakes up on a spaceship millions of miles from home with no memory of his identity or his mission. He soon discovers he is the sole survivor of a desperate, last-chance effort to save humanity from an extinction-level threat: a mysterious, star-eating algae that is killing the sun. As his memories return, Grace must use his scientific knowledge to solve an impossible mystery, often with the help of an unexpected alien ally, to prevent Earth from freezing over.