One Detail From The Project Hail Mary Book That I Really Wish Was In The Movie

Spoilers for both the book and the book-to-screen adaptation of Project Hail Mary are ahead! Read with caution, and go see the movie in theaters.

If you read Project Hail Mary without knowing much about it, the reveal of Rocky is a massive surprise. However, I never thought it was the biggest shock of the story. The big twist to me was centered around the question: Why was Ryland Grace, a middle school science teacher, sent to space? Well, the answer is complex and tragic in both Andy Weir’s novel and the film that just premiered on the 2026 movie schedule.

However, there’s one detail from the book about Ryland’s reason for going to space that was left out of the movie, and I really wish it had been included.

In The Movie, Ryland Grace Is Picked Because He’s The Only One Who Knows The Science

Along with Project Hail Mary’s stunning visuals and standout performance from Ryan Gosling, it also brilliantly lays out a mystery about how his character, Ryland, ended up in space.

Then, eventually, it’s revealed that he didn’t opt into this mission. No, he was forced into it. After two astronauts died in preparation for it, they needed replacements. Ryland was really the only scientist who knew the material well enough to conduct the biology necessary for this mission. So, Stratt decided to send him.

He was their only hope. However, he didn’t want to be and refused to go. That wasn’t an option, though, and he was ultimately forced onto the spaceship against his will. That all happens in the book, too; however, there’s another reason Ryland was chosen that isn’t addressed at all in the movie.

In The Book, There’s Also A Genetic Reason Why Ryland Grace Is Chosen To Go To Space

Now, there’s no question that Project Hail Mary was one of the big 2026 adaptations I was the most excited about, and PHM does live up to its stellar reviews. However, leaving one detail about why Ryland was chosen to go to space out of Phil Lord and Christopher Miller’s movie disappointed me just a little bit.

So, in Andy Weir’s novel, it’s established that a certain gene combination is needed to survive the coma the astronauts would go into during their journey. That severely limits the number of people eligible for the mission. However, one person who does have those genes is Ryland. Therefore, when they lose some of the people who were supposed to go to space, Stratt makes the call to put Ryland on the ship. That leads to the following conversation in the novel:

“The decision’s been made,” Stratt said. “Really, the decision made itself. There’s no time to train a specialist in everything they need to know. There’s just too much information and research to learn. Even the most brilliant scientists wouldn’t be able to glean all of it in just three days. And remember, only about one in seven thousand people have the gene combination to be coma-resistant.”

That's when Ryland "got a sinking feeling" and realized that Stratt was talking about him. She then confirmed that, noting that his tests for this gene were positive. In short, he was "that one in seven thousand."

By adding this genetic element, Ryland becomes quite literally the only person capable of doing this mission after the unfortunate loss of the others. Or at least that’s how I felt. So, when Stratt forces him to do it, he denies her, and then he is eventually sedated and taken on to the ship; it hits like a ton of bricks in multiple different ways.

From Stratt’s view, I understand why she makes him go. He’s their only hope. From Ryland’s point of view, being sent on a suicide mission like this against my will is unfathomable. So, the emotional toll of this choice was heavy and hard to bear.

It’s like that in the movie too. However, without the one in seven thousand genetic combination, the circumstances they’ve found themselves in are a bit less severe. Obviously, Ryland still is one of the only people for the job, but it’s not quantified in the same way.

So, yes, I do really wish this detail about his genes had been in the movie.