Project Hail Mary opens with a man waking up in a spaceship, alone except for two dead crewmates, unable to remember his own name. Through a series of flashbacks triggered by returning memories, he pieces together who he is (a junior high school science teacher named Ryland Grace) and why he’s in interstellar space (Earth’s sun is being dimmed by a mysterious organism, and he’s on a last-ditch mission to find a solution).
Like The Martian, the book is built around scientific problem-solving. Grace has to figure out how the alien organisms work, develop a way to stop them, and get the information back to Earth before it’s too late. Weir’s research is again thorough, and the solutions Grace comes up with are grounded in real physics, chemistry, and biology, even when the scenario itself is speculative.
What makes this book different from The Martian is the relationship at its center. Partway through the story, Grace encounters an alien being, and the two must find a way to communicate and cooperate despite having completely different biology, language, and ways of thinking. This relationship becomes the emotional heart of the book, and Weir handles it with more warmth and depth than anything in his previous work.
The structure of alternating between present-day space sequences and flashback Earth sequences works well for the most part, though some readers find the flashbacks slower than the space sections. The humor is still present but more restrained than in The Martian, and the stakes are higher, both for the character and for the planet.
For founders and science-minded readers, the book is a celebration of the scientific method applied under extreme pressure: observe, hypothesize, test, iterate. It also has something interesting to say about cooperation across differences, which is relevant far beyond the realm of science fiction.
The ending has divided readers, with some finding it perfectly satisfying and others feeling it’s a bit too neat. But the journey is excellent, and the alien character is one of the more memorable in recent science fiction.
