Project Hail Mary

Comparing the novel and the movie

I went to see Project Hail Mary last weekend. That is, after I read the book. I thought it would be interesting to do a comparison between the pages and the screen. Quick warning: I try to avoid major spoilers here, but a fair comparison does require certain details. So don’t say I didn’t warn you!

The book

Simply put, I thought that Project Hail Mary as a book, written by Andy Weir, was an absolute delight.

I come across very few hyped books that truly live up to the expectations that certain reading communities raise. Of course, I enjoy many well-known, as well as not-so-well-known, novels in a variety of genres, whether literature or general genre fiction, but I usually get the itch when readers claim that a novel changed their lives. Assuming this means changed for the better, good for them. This is a free country. I applaud your pliability if a novel can have that effect on you. I don't think I ever read a novel that changed my life. I don’t need it to. However, I have read a few that may have changed my perspective or refined my views on the subject matter. I consider that no more than an interesting by-product of the reading experience for me. My main goal when picking up a book is simply to exit my own daily life for a while and step into someone else’s. Experience things that are beyond my ordinary existence. Feel intrigued by the characters and the plot. Dwell in the ambiance of a peculiar setting, without losing sight of the story.

Coming back to project Hail Mary, the book! And what a book this is. For those of you who don't have a clue about this book, it is a scientific space-mission novel centered around having to save the sun, which is slowly dying. An ordinary science teacher—Ryland Grace—ends up placing himself unwittingly as the primary astronaut. He wakes from his coma-induced state in a hyper-advanced spaceship and realizes he is the only astronaut left on this mission. But he won’t be alone for long...

As I said, I thoroughly enjoyed reading Project Hail Mary. The characters feel very authentic (Ryland Grace is one of those guys who is very lovable, despite his tendency to run away when things get a little tough), and the story is heavily dipped in space science. By the time I finished the book, I was convinced Andy Weir was an ex-astronaut or some other highly knowledgeable scientist. The scientific language throughout the novel was just too detailed, too dense, to see any alternatives. Well, I was wrong! It turns out Andy is just an absolute space-fanatic! Pair this with the research and support from several scientists, and this is how he infused Project Hail Mary with this flavour of science-techy-cool stuff. Considering they were never my favourite subjects at school, I certainly devoured the science in this novel, as it made the entire reading experience ultra-authentic.

The movie

The similarly titled screen production (released in the US on March 20, 2026) has Ryan Gosling playing the role of Ryland Grace. (I thought it was a fun fact that they happen to share the same initials.)

But here’s my take on the movie, and the way they have chosen to visualize this chunky (around 480 pages) novel. That length would have posed the first, and potentially largest, challenge for the screen producers, and it was confirmed by the way it received multiple cuts before being released. The original assembly cut was over four hours long, with an early screened version running 3hrs45. Eventually, the movie became a “lean-and-mean” 2hr45, and most of the cutting was done in places where the aforementioned scientific “sauce” would have been. Does this mean that the science was lost? No, definitely not. There is still plenty of this in the movie, albeit it has gone from a bouillabaisse to a light seasoning.

One noticeable difference was the reason why Grace was sent to space. Initially, he was leading the ground-based research on Astrophage, the organism consuming the sun. But when a key crew member is lost in a pre-mission experiment, project lead Eva Stratt wants to send Grace instead. In the movie, the justification for this comes down to Grace having the exact skillset as a (former) molecular biologist, combined with the fact that Grace has been closely involved in the project from the get-go. The key breakthrough in their research, figuring out how Astrophage breeds, is one he takes the credit for, after all. But in the novel, there is another reason why Grace is sent as replacement crew member. The trip from Earth to Tau Ceti, the planet they were heading, would take 12.9 years from Earth's perspective. This is roughly 4 years and 8 months for Ryland Grace (due to time dilation in space). Psychologists warned for the extremely high risk of the crew harming each other or themselves if consciously confined for that long, which led the team to the idea of coma-induction. Essentially force the crew into a coma for the years they were travelling on board the Hail Mary, the ultra-advanced spaceship fuelled with (yes, bizarrely...) Astrophage. As testing progressed, it became clear that only 1 in 7,000 people had the rare genetic trait to wake from a coma-induced state and live on healthily. Grace had been tested early on, and he possessed the gene. The movie completely bypasses this detail, and you can understand why. With an initial running time of 4 hours, it would have taken a lot of time to explain this gene—besides, there were enough reasons for Grace to be sent out as it was; all of them solid scientific breakthroughs with Astrophage.

Another interesting difference between the novel and the movie is the (dis)connection Grace feels when he finds and releases the bodies of the other two crew members. Yao and Ilyukhina, despite having the gene, have not survived the coma-induction. After Grace finds them, he salvages some personal items from their packs and sends their bodies off into space. In the novel, despite still suffering from severe amnesia and remembering little detail of the time he spent with these people, he is still tormented by a deep sense of loss. Personally, I thought this was a lovely detail, as it suggests that knowing isn’t per definition the same as feeling, and creates the idea that emotion is packed deeper inside our subconscious than facts and events. In the movie, however, Grace has no clear connection with the other two crew members. His sadness is purely for them, their undoubtedly brilliant minds, and perhaps the fact that losing them means gaining true solitude.

There are a couple of details in the movie that the book didn’t touch on, however. Grace spends considerable time in a wraparound, immersive movie space on board the Hail Mary. Correct me if I’m wrong, novelphiles out there, but I do not recall this space being mentioned in the book. It makes sense they added it in the movie, though, as it was a chance for Grace to “show” Earth, and created some stunning backdrop visuals that screen production is so great at.

Earlier in the movie, Grace physically fights and runs from the guards trying to contain him when Eva Stratt has told him that his “choice” of not wanting to join the space crew really isn’t a choice. It is followed by a rather hilarious scene of Grace clawing his way on top of a shelf to avoid getting caught. I loved how they added these details, and it was well-aligned with the directions the novel gave, in which Grace also rejects the mission (and is temporarily locked up).

Now to the most notable difference of all: entering the other spaceship! Okay, this is very tricky terrain. Despite giving my spoiler alerts in the introduction, I can’t help but want to tread this very carefully in case you haven’t read or watched either art form. But those who have done so, you know! The book skipped past this; Grace didn’t get to see the other ship with his own eyes, yet the movie did take (several costly minutes!) to show the insides of it. Visualized in an almost abstract form, a little detached from what humans may consider “shape”, I still thought this was a nice touch.

And then there was the ending...and YES, the book and the movie end in virtually the same way. Some people may have found the ending unsatisfying (we really can’t debate taste, guys!), but I personally thought it was a refreshing conclusion that made neither for a happy-ending that includes unicorns and rainbows, nor a depressing “everybody dies” scenario. It was elegant and fitted our main character very well.

If you have read the book and you are wondering if it pays to go and watch the movie, I’d say: YES! As I sat in the cinema last weekend, I seriously wondered if everyone there who had never learned about this story would be able to grasp all the plot events (after all, they did cut out nearly 2 hours!). It was a great experience for me, and I could understand all the decisions made by production. After all, they kept as true as possible to the original story, which, as an author (and human being), I can appreciate. It is a wonderful production worth seeing in the cinema for the obvious space visuals. Or even just to see Ryan Gosling rolling out of his coma-bed in space (a bit like a shrimp on land), not fully having gained his muscle-strength yet.

If you have watched the movie and you wonder if it is worth reading the book, I still say: YES! The novel will be a very different experience, and if you are a stickler for quality detail and impressive research all wrapped into an incredible story about existence, friendship, and survival, you should pick up the book. I am aware that your brain may replay scenes from the movie as you read the book (because the brain is a little lazy like that), but I still consider it an excellent read for you. It may answer some questions the movie raised and didn’t answer, simply because of its time-limitations.

Both the book Project Hail Mary and the movie were done very well and are outstanding experiences in their own right. Enjoy and feel free to leave your thoughts on either, or both!