As book-to-screen adaptations go, Project Hail Mary already ranks up there with some of the best, in my opinion. Sure, Phil Lord and Christopher Miller's adaptation of Andy Weir's novel had to make some changes and leave a few things out, but overall, as a fan of the book, I loved the movie. I thought it did a good job of covering the necessary elements of the science-heavy story, while also leaving plenty of room for Ryan Gosling's character and his new pal Rocky to bond and figure out how to save their planets. There was one thing the 2026 movie didn't explain -- and to be fair, the book doesn't really either -- but it turns out, Andy Weir does know the answer... and he's not ready to tell us.
Spoilers from Project Hail Mary ahead!
In both the book and the movie, Ryland Grace wakes up from a medically induced coma aboard a space ship. Long before he figures how how he ended up there, he discovers that the two other passengers -- Yáo (Ken Lung) and Ilyukhina (Milana Vayntrub) -- have died at some point along the way. Judging by their states of decomposition, it wasn't recently either. It's never explained how exactly Yáo and Ilyukhina died, however Andy Weir apparently does know the answer. This was one of the questions that came up during Wired's video featuring Ryan Gosling, Andy Weir, Phil Lord and Christopher Miller, where they answer the 50 most searched questions about Project Hail Mary. One of the questions that came up was, "what happens to the other two astronauts?" Weir's response was:
So, I know the answer to this, but I'm saving it for potential sequel materials.
If you haven't read the book, or you forgot how it was explained, it'd be fair to assume that Yáo and Ilyukhina died due to being in a coma for such a long time, since there were risks to that. The movie doesn't go into the dangers of these longterm comas as much as the book does, but it would still be a reasonable guess as to why two of the three astronauts didn't survive the journey. However, the book does imply that Yáo and Ilyukhina's deaths were due to something the medical robot couldn't treat. Ryland's actual speculation is, "they must have had some medical situation arise it couldn't figure out." So it presumably wasn't the coma itself that was the issue, but a lack of necessary treatment for each of their medical problems.
The fact that Andy Weir knows what caused their deaths but is keeping quiet about it for potential future use is certainly intriguing. Now, before we get too excited about sequel talk, from what we know, Andy Weir is not currently working on a sequel to Project Hail Mary right now. From what he recently told ScreenRant, he is working on a new book, but it's a standalone sci-fi novel and not a sequel. He went on to explain that he has "bits and pieces" for sequels, but not enough to get started with just yet.
So we may have a bit to wait if he does plan on revisiting Project Hail Mary for a followup. Still, I can't help but wonder how the ailments of Yáo and Ilyukhina might somehow factor into a possible sequel. My only guess is that whatever Weir has in mind could involve a similar trip through space? After all, Grace sent back information to Earth, which no doubt includes the fates of Yáo and Ilyukhina. Perhaps whatever caused their deaths will factor into future space journeys where finding a way to prevent similar issues is a priority. Maybe a trip to Erid someday?
We can only speculate at this point, but right now I'm feeling a bit relieved to know that we're not actually supposed to know what happened to the two other astronauts, and also a bit excited to know that Andy Weir might have plans to revisit story in the future. Good-good-good!
