Screenwriter Drew Goddard has made a statement on the debate that happened while figuring out the ending of Project Hail Mary. Goddard, along with directors Phil Lord and Christopher Miller have reportedly “fought” to keep the book’s original ending.

In an interview with Indiewire, Goddard stated:

“Whenever you’re doing anything that feels bold or different, I’ve learned, people are going to push back against it,”

“There’s a human quality in what we do that you feel comforted if it’s been done already. So anytime something’s different, and you take a chance on something, there’s an initial reaction to say, ‘No, no, no, no, don’t do this, it feels weird. This is too new. I don’t understand this.’”

The film adaptation for Project Hail Mary wasn’t far off from Andy Weir’s novel, but there was one major change that contrasts the original ending.

Spoilers Ahead.

The ending is bittersweet. Ryland Grace (Ryan Gosling) saves Rocky. Grace saves Erid. Grace saves Earth. 

After launching the tune of The Beatles to send Taumoeba back to Earth, it takes him approximately ~60 Earth days (in the film) to find Rocky’s ship in the vast expanse of space. He joins Rocky on Erid for an indeterminable amount of time, but he’s happy.

He has “Armando”, the robot arm that helped him survive on the Hail Mary, a special dome that mimics Earth’s atmosphere, and a beach that Eridian scientists have built for him. Most importantly, Grace continues to do what he does best, being a middle school teacher.

They don’t explain how Grace manages to survive on Erid as he eventually runs out of rations from the Hail Mary, but it’s written in the novel that a team of Eridian scientists manage to clone his muscle tissue and grow it in labs. Which means that Grace survives on eating his own cloned human meat. He calls them “meburgers”. 

The essential, major difference between the film and book’s ending is Grace’s age.

But First, Let’s Do The Math

While this is all up to speculation and theory, this Reddit thread has solved the science. Users on Reddit have calculated that Grace travels from Earth to Tau Ceti for about 3.9 space years at a G-Force of 1.5g. That means about 13 years have passed on Earth from when Grace wakes up. The time Rocky and Grace spend together solving the mystery of Astrophage and discovering Taumoeba is unknown, but it was enough for Rocky and Grace to learn how to communicate.

There isn’t an exact number on how long it would take for two people to learn each other’s languages, let alone an alien one, but this Tandem article on Language Exchange says:

“Developing fluency in a new language requires a significant time commitment, but how effectively that time is used is arguably more important than the hours logged.”

So we can at least conclude that Grace and Rocky were learning about each other for a while.

Crunching Down the Numbers Even More

In the novel, Grace mentions he’s 32 days into his four year journey home¹ when he finds out the Taumoeba is resistant to Xenonite, realising that it’s been “three days since the Great Taumoeba Escape.”² Grace then drifts off to sleep, waking up six hours later³ (presuming a day has passed), battling with himself on whether or not to return to Earth or to save Erid, but quickly deciding to go back and save Rocky.

It takes at least six weeks⁴ and nine and a half hours⁵ to find Rocky’s ship and apparently (tpresuming he’s close to Tau Ceti), the journey between Tau Ceti and Erid is 10.02 lightyears, thanks to the previously mentioned Reddit post. 

For my own reference, I’ve figured out is that it takes 78 days for Grace to leave and then return to Rocky. When Grace sends the Beatle probes back to Earth, we can presume that they’re travelling at the same 1.5g that the Hail Mary was, which means it would take them 13 years to get back to Earth.

So What Exactly is the Big Change?

In the final chapter, Rocky excitedly tells Grace that Sol, Earth’s sun, has returned to “full luminance”, concluding that the Beatles had returned to Earth, and scientist’s on Earth took “less than one of [Earth’s] years”⁶ to reverse the effects of Astrophage.

Rocky then asks Grace, “So will you go home now, or will you stay?” and Grace replies,“I don’t know. I’m getting old and the trip is long.”

In the book, Grace has a cane and explains that the high gravity of Erid has made his bones degenerate faster⁷. He’s “fifty-three years old now, but [he’s] not sure,” due to the time-dilated travel. However, he can “accurately say seventy-one years have gone by in Earth since I was born.”

With at least 27 years (and 78 days) of space travel, time dilation, living off rations and “meburgers”, the trip has no doubt taken a toll on Grace’s wellbeing. He has a cane for the high gravity levels on Erid, and suffered a number of diseases from being malnourished. 14 of those years would have been on Erid.

In the film, Ryan Gosling hasn’t aged at all. He’s the exact same Ryland Grace. He’s gorgeous, sprightly, and walks without a cane. That is the major difference between the book and its adaptation.

Does this Change Much from the Movie?

In contrast to his refusal to die for Earth, Grace chooses to save Rocky and Erid. Grace’s story comes full circle from his cowardly decision to risk the Hail Mary mission in order to save himself, to sacrificing himself to save Rocky – his one and only friend. Even the most cowardly can be brave, or at least find someone to be brave for. “Whenever I think about my impending death, I think of Rocky instead… I’m coming, buddy.”⁸

Removing the visible, physical hardship that Grace goes through in the novel in order to overcome his cowardice, changes the tone of the ending in the film because it doesn’t justify how much Grace has sacrificed. Ryland Grace loses most of his life and spends a considerable amount of time in an atmosphere that isn’t his own to save two worlds. His age reflects his journey from reluctance, to one of bravery.

His reluctance to go from Erid to Earth carries a lot more weight if Grace was older. He has nothing left for him if he does go back; a lot of Earth would’ve been desecrated from at least 26 years of Astrophage. He created a whole new life for himself on Erid and he’s adjusted despite the difference in gravity and lack of proper nutrients. If he’s the same young, handsome Ryan Gosling, his hesitation to return to Earth feels more like a shallow decision. It would take him 4.26 years to travel from Erid to Earth, which would be less strenuous to a 45 year old. It is a stark contrast if he were 71.

Final Thoughts

I do think there would be more depth in Grace being an older man in the film’s ending, even just for a few minutes. But this doesn’t mean the movie wasn’t amazing. Emily’s review sums up exactly why I adore this film:

“Instead of bleakness, it embraces optimism. Instead of loneliness, it embraces camaraderie.”

To date, Project Hail Mary has grossed $140 million worldwide in its opening weekend and is currently number 89 on Letterboxd’s top 500 films.

Header Image Credit: Sony Pictures

Footnotes are in reference to this copy of the book published on October 5 2022.

1. Page 434 ↩︎
2. Page 443 ↩︎
3. Page 446 ↩︎
4. Page 455 ↩︎
5. Page 460 ↩︎
6. Page 473 ↩︎
7. Page 472 ↩︎
8. Page 456 ↩︎