The Complete Project Hail Mary Timeline Explained

Contains spoilers for the book and movie versions of "Project Hail Mary"

Part of the reason "Project Hail Mary" is leaving critics stunned and audiences enraptured is the way this gripping sci-fi story about an alien microbe dimming the sun is told. Ryland Grace's (Ryan Gosling) character wakes up from a forced coma with amnesia, and it's only slowly throughout the story, via broken flashbacks, that we realize how he came to be in the position of being humanity's only hope. This storytelling structure leads to several powerful reveals, including how Grace ended up on the Hail Mary spacecraft in the first place. But it also has the effect of breaking up the story, making the choppy narrative difficult to piece together.

If you haven't seen the film yet and you're not quite sure what it's all about, check out Looper's "Project Hail Mary" explainer video before heading to your local cineplex for the full lowdown on the property. If you've already been to see the movie (or you've read Andy Weir's book of the same name) but you're still a tad confused about the order of events, we've got you covered: We've gone ahead and laid things out in chronological order below. Here's the full timeline of all the biggest beats from the epic story, from the moment Grace meets Project Hail Mary head honcho Eva Stratt (Sandra Hüller) to that incredible closing scene on Erid.

The "Project Hail Mary" timeline could start at a few different points. The alien microbe Astrophage (essentially an interstellar mold that grows on the surface of stars) has been impacting stars around ours for an indefinite amount of time before humans notice their sun dimming. But Andy Weir doesn't specify how long Astrophage is at work in his book. So, our first real point of measurable time is roughly half a century before Ryland Grace wakes up in the system of Tau Ceti, a star that has Astrophage but isn't dimming like the others.

The scene in question takes place on the planet Erid. A giant starship takes off with 23 Eridians on board. One of these is the ship's engineer, a being we eventually get to know as Rocky (James Ortiz). Rocky's space is in the back of the ship, tucked under the Astrophage tanks that power it — the microbe also works as rocket fuel. This insulates him from an unexpected and lethal enemy: radiation.

A few years later, the Eridian vessel reaches the Tau Ceti system, but Rocky is the only crew member still alive. He proceeds to float around the system, trying to figure out how to discover the scientific answer to the Astrophage invasion, but his lack of science prevents him from succeeding. He remains in the system, hopelessly waiting for a solution for the next 46 years.

While there are several flashbacks to Grace's pre-Hail Mary life on Earth, these can be condensed into a fairly straightforward timeline that kicks off while Rocky is already orbiting Tau Ceti. Grace's part of the story starts with the reluctant hero teaching middle school science before Eva Stratt taps him for the Hail Mary mission. Grace quickly finds himself in a lab, where he makes several initial discoveries about the invasive, star-destroying microbe Astrophage, including how it breeds.

At this point, Stratt brings Grace fully into the Hail Mary project. The teacher turned leading authority on all things Astrophage finds himself on an aircraft carrier, neck deep in the planning for the desperate interstellar mission. Grace gets to know the astronauts selected for the one-way trip and helps plan out the design of the ship as well as make sure they breed enough Astrophage to power it to the nearby star system of Tau Ceti.

He also witnesses some wild moments, including one that was cut from the movie, where Stratt and her team detonate 241 fusion bombs in Antarctica to deliberately release methane gas and help insulate the Earth from a cooling sun. Everything seems hopeful until, with launch right around the corner, things go terribly wrong.

Right before Grace bids the Project Hail Mary crew adieu, a mistake happens. After months of careful planning, someone measures out a tiny quantity of Astrophage that is exponentially too large for an experiment, and the super-powered stuff goes off, vaporizing a building, along with the mission's lead scientist and his backup. Stratt, desperate to get the mission off in time to save humanity, taps Grace as the backup. He's informed about Astrophage, up to date on the mission, and is one of the few people who is genetically capable of handling an induced coma.

The only issue? Grace can't muster the bravery to go. He sees the need, of course. He fully understands that he's the only person capable of the job and that the future of humanity depends on it. But he chickens out. He takes the cowardly path and says that he straight up won't go. This forces Stratt to take the nuclear option, kidnapping Grace, forcing him into a coma, and bundling him onto the Hail Mary for a multi-year trip with his two volunteer comatose compatriots.

We're now at the beginning of the book and movie alike. Both start with Grace suddenly waking up from a coma. He's been in that state for over three years. As he was traveling at close to the speed of light, 13 years have passed on Earth — as Grace says in the book, "Relativity is weird." His two companions, Yáo Li-Jie (Ken Leung) and Olesya Ilyukhina (Milana Vayntrub, who is best known for her AT&T commercials but has been in plenty of films and TV shows), didn't make it – the interstellar travel proved too much for their bodies and they died on the trip.

Grace spends the days following his awakening trying to figure out where he is and he slowly starts to remember things. He also explores the ship, learning (and in many cases re-learning) its capabilities. He gives his fellow crew members a space burial, figures out that he's there to find out more about Astrophage, and starts trying to plan out his next steps. It's at this point that the story takes an entirely unexpected direction when he realizes he's not alone.

As Grace arrives in Tau Ceti space, Rocky realizes that he's finally not alone and races over to the new alien ship to make an introduction. The moment of first contact between humans and a sentient alien race is exciting. Rocky kicks off the communication, and when Grace realizes his new neighbor isn't hostile, he's thrilled. The two become fast friends and spend days figuring out how to communicate. Then, they spend more time learning about each other's culture, backstories, and how they managed to cross paths.

Rocky uses the Eridian metal xenonite to build environments where he and Grace can work alongside one another (Rocky needs ammonia and heat, while Grace needs oxygen and less heat). With Rocky as the engineer and Grace as the scientist, they set about solving the biggest question facing their races: how to deal with Astrophage.

Their attention turns to the nearby star Tau Ceti, which hasn't dimmed like the rest of the stars in the region. They deduce that its orbiting planet, which they name Adrian after Rocky's past partner, has to have the answer they're looking for, so they head that way.

Grace and Rocky decide that if Astrophage has a predator, it must be lurking in the atmosphere of Adrian. The only way to find out requires a dicey expedition to collect a sample. Rocky uses his marvelously strong xenonite to build an extremely long chain. We're talking a 10 km-long chain. That's over six miles. 

A sample-collecting device is attached to the end of the chain, and the ship is lowered into orbit. Once the Hail Mary is relatively stable, Rocky releases the chain, dropping the sampler into the atmosphere. Grace heads out to the hull, where he retracts the chain and retrieves the sampler.

This is where one of the more dicey moments takes place. The ship is damaged while trying to leave orbit. Grace is crushed by the centrifugal weight, forcing Rocky to exit his ammonia atmosphere to save the day. When the dust settles, everyone is alive, but Rocky nearly dies in the process.

It takes the unconscious Eridian a long time to recover. During that time, Grace learns about the extraterrestrial micro-organism Taumoeba, the predator that is keeping Astrophage in check around Tau Ceti. Rocky eventually wakes up, and they each prepare to take the Taumoeba solution back to their respective home worlds.

At this point, the story seems set to end on a high note. Rocky is headed toward Erid, and Grace is speeding toward Earth. They both have what they need in hand to save their civilizations. Well, not in hand. In xenonite breeding containers. That's where the final twist starts.

The special strain of Taumoeba that they've discovered learns to hide in the walls of the xenonite cells. This adaptive quality helps it escape. Grace catches the disaster before the Taumoeba eats all of his Astrophage fuel. But Rocky? His ship is made entirely of xenonite. The Taumoeba escapes and wreaks havoc, leaving the Eridian adrift in space.

Grace realizes the situation. He sends the four beetle probes he has racing back toward Earth with specimens of Taumoeba for his human colleagues to use to stop the Astrophage on the sun. But Grace himself? He's finally found his willingness to make the ultimate sacrifice. Not for his own kind, though. For Erid. He turns his ship around, finds Rocky's ship adrift in space, and brings his Eridian friend on board.

With Taumoeba safely speeding toward Earth in the beetle probes, Grace makes the ultimate sacrificial move by taking Rocky home to Erid in the Hail Mary. The story skips ahead at this point and we discover that the interspecies friends have reached Erid and successfully eliminated the Astrophage threatening the planet. Eventually, they also see confirmation that Earth's sun is burning brighter, indicating that the beetle probes reached their destination and that Stratt and company managed to use the Taumoeba effectively.

As for our protagonists, Rocky is reunited with his people and they quickly use their engineering skills to help build Grace a living space on Erid. This environmentally controlled area allows Grace to dwell on a hostile alien planet in comfort, with many of his normal Earth amenities. We're left with the friends chatting before Grace heads over to the edge of his enclosed space, where he talks through the barrier to a new class of young Eridians whom he is teaching.

Interestingly, in the movie version, Rocky says the Hail Mary is fixed, and Grace is still considering whether or not to return to Earth. In the book, while Grace admits that he could go home at some point, he is definitively committed to teaching science on Erid for the foreseeable future.