Project Hail Mary By Andy Weir Book Summary
Check out this summary of Project Hail Mary, Andy Weir’s latest science fiction best seller that’s being made into a movie. This summary is to remind you of what happened in the book before you read my review or see it on the big screen.
If you haven’t read the whole book, I highly recommend it to get the full effect of how good the book is. Andy Weir does what he does best: takes hard science, wraps it in humor and heart, and builds a survival story that feels both wildly entertaining and oddly believable. If you loved The Martian, this one goes deeper. If you have never read Weir before, this is where you start.
Chapters 1-2
Waking up in a hammock-like bed not remembering anything, the narrator finds himself hooked up to all kinds of tubes and sensors with two robot arms in the middle of a circular room taking care of him. When he works up the strength, he eventually notices two other beds with people who have died in them, so he makes it up a ladder and through a hatch in the ceiling into a laboratory. After looking around the lab and testing things, he realizes that he’s a scientist who’s very familiar with physics and that the gravity in the room is too high, so he can’t be on Earth.
He suddenly has a memory of meeting with his friend Marissa who tells him that the Earth’s sun is dimming because the Petrova line, a mysterious arc of unknown material giving off infrared emissions, that starts at the sun and widens around Venus. He also remembers that an instant ice age will start in the next few years if him and his crew don’t fix the Petrova problem. After he remembers he’s a teacher, he remembers watching the broadcast where scientists sent an international spacecraft to Venus, and found the particles making up the Petrova line move under the microscope meaning they’re some kind of alien life form.
Chapters 3-4
In another flashback, he remembers getting recruited by Eva Stratt to look at the alien particles because he wrote a controversial paper asserting that only Earth life needed water but not all life needs water (which later got him ostracized from academia). Remembering his own name is Ryland Grace, he uses his name as the voice password to get into the room above the laboratory which is full of computer screens. Then, he remembers being forced to examine the alien particles and discovering they consume energy and emit light as propulsion, meaning they’re absorbing the sun’s energy that the Earth needs.
Based on the screens, Ryland figures out he’s in another solar system on a space ship called Hail Mary powered by the Astrophages, what he named the particles that he suddenly remembers do have water in them. He also finds four tiny, beetle-shaped ships that he’s supposed to send back to Earth with his information. The ship doesn’t have enough fuel to get him back to Earth, and he figures it took years in an induced coma to get him to this point on a last-chance mission to save the human race.
Chapters 5-6
Ryland remembers discovering that Astrophages are on the sun to absorb energy before looking for the carbon emissions on Venus. They propel themselves to Venus, collect enough carbon to reproduce, and then propel themselves back to the sun for more energy. Scientists now working on the Astrophages like Ryland found out it’s like an algae infecting stars within 8 light years of each other, dimming them by 10% before moving on. Scientists wanted to send a ship to Tau Ceti, the only star around the sun that hasn’t dimmed to find out why the Astrophages didn’t infect it.
Ryland was taken to a Chinese aircraft carrier in the ocean with other scientists where they found out Astrophages can convert energy to mass to store it. Back on the ship, he figures out he’s been on the ship for over three years (he experienced) in the induced coma, and that means he’s been gone for thirteen years on Earth because of relativity. As his ships enters an orbit around Tau Ceti, he sees the star also has a Petrova Line even though it’s not getting any dimmer, but he also sees an alien spaceship in the solar system.
Chapters 7-8
When Ryland slightly accelerates the ship, the other ship, Blip-A he calls it, accelerates at exactly the same rate, so Ryland figures its there for him. Then, he sees their ship release a cylinder towards his ship, so he gets into his suit to go out and catch it while tethered to the outside of the ship. Once he has the cylinder back inside the ship, he remembers the Hail Mary ship breaks in half and spins with connecting cables to turn into a centrifuge, so he can use the lab instruments under gravity.
In the lab, he finds out the cylinder is made of xenon, which should be impossible, and it’s so hard it broke the chisel Ryland tried to use to get a piece of it. Inside the cylinder, there’s a 3D map of all the local star systems, and Ryland figures out the alien species is from around the star 40 Eridani which also has a Petrova line. Thinking they’re here for the same reason, Ryland adds a little Earth to the Sun on the model with a Petrova line and sends it back.
Shortly after, they send back another cylinder which has a model of the Hail Mary and their ship with a connecting tube. Ryland figures they want to meet.
Chapters 9-10
Next, Ryland goes back outside and breaks off a small piece of his hull to send over to Blip-A. After going back inside and waiting, the other ship slowly gets closer and attaches a tunnel from their ship to the airlock door on the Hail Mary, and Ryland sees a divider made of the xenon material in the middle. On his side of the divider, he lets the air of the ship pressurize it, and then through a small clear part of the divider, he sees a hand-like thing made of rock holding a figurine of him getting into a figurine of his ship.
After seeing the alien hand and going back onto his ship, he hears a knock on his door from the tunnel and goes back to find the divider is now completely see through. On the other half of the tunnel is a spider-like alien, about the size of a Labrador, that has a pentagon shaped body with five legs/arms with three fingers each that appears to be made of rock, so Ryland calls him Rocky. When Ryland mutters to himself, he hears Rocky respond with something similar to whale noises, so even though he can’t see a head, ears, or eyes, Ryland concludes Rocky can hear him, has a language of his own, and is trying to communicate with him.
Ryland notices that Rocky also left two spheres on Ryland’s side of the divider that contain more models that tell Ryland Rocky lives on a planet (Ryland calls it Planet Erid) with an atmosphere of ammonia with 29 times as much pressure as Earth. Then, Ryland shows Rocky a clock from his lab, and Rocky brings back a his own clock that shows Ryland one second for him is 2.66 seconds for Rocky as well as what Rocky’s numbers look like.
Chapters 11-12
After a short nap, Ryland returns and figures out that Rocky doesn’t ‘see’ things visually but through sound waves because Rocky can still copy his motion if Ryland is standing behind a sheet of aluminum. So Ryland thinks to bring computer software that will record the notes Rocky makes, and Ryland can give a word to each sound. Ryland holds up a popsicle stick as he says one, and then records the sound Rocky makes that means one.
Over several days, Ryland records Rocky sounds and notices that Rocky remembers everything Ryland says without a computer and can translate. After several days they can now understand each other through the computer translation, and Rocky reveals that he’s the only one left on his ship that originally had 23 crew members. Rocky also installs an airlock box that allows them to exchange materials.
Chapters 13-14
Over several days of talking, Ryland learns that Rocky’s species watches each other sleep, so Rocky insists that they both sleep in the tunnel. Ryland also learns that Rocky’s crew must have died of radiation poisoning from hydrogen atoms in space which Rocky didn’t know about. Then, Ryland remembers how scientists figured out Astrophages store energy by making neutrinos, so they also used a mix of Astrophages in oil as insulation around the Hail Mary to protect from radiation.
Suddenly, Ryland remembers that scientist on Earth set off nuclear bombs near Antarctica to melt a huge chunk of it and release methane gas trapped in ice. The greenhouse gases heat up the earth, and gave them more time for project Hail Mary because the Astrophages were already cooling the Earth too much. Then, in their tunnel, Rocky decides to build himself a wearable device in a xenon ball that will allow him to come onto Ryland’s ship to see the human technology.
Chapters 15-16
Rocky, who was the ‘engineer’ of his crew, builds a new tunnel, and comes to Rylands ship where he asks to move in so they can work together. After Ryland agrees to figure out the Astrophage problem together, Rocky brings a bunch of stuff from his ship, and builds tunnels with his atmosphere and pressure throughout the Hail Mary. Rocky also says Ryland can have his extra Astrophage fuel from his ship to get back to Earth when Ryland thought he was going to die out here with no fuel supply to get back.
Ryland and Rocky decide to drive the ship to the planet in this Tau Ceti system that the Astrophage is found at. Then, Ryland remembers they figured out only few humans have the genetic mutation to stay an induced coma for that long without consequences. He wasn’t part of the original crew or even the back up crew, but he did have the mutation since the whole team of scientists was tested.
Chapters 17-18
Ryland and Rocky make it to the planet near Tau Ceti, which they name Adrian, and take a sample of the Astrophages from its Petrova line. Under the microscope, the sample only has half the expected Astrophages, so they assume that Astrophages have a predator because there’s lots of other organisms in the sample. But when they try to determine the main predator, they can’t figure it out.
After talking it through, they decide they need a sample of Astrophage and the other life forms from the ‘Astrophage breeding zone’ which they determine is lower in the planet’s atmosphere. But the ship can’t go that low without getting pulled down. So they make a sample box attached to a super long chain to ‘go fishing’.
Chapters 19-20
After two weeks of making a chain long enough, they drop lower into Adrian’s atomsphere and drop their sample box Rocky made. Once the sample box closes with the sample inside, Ryland has to go out onto the ship and use a winch they made to pull it back up. Ryland finally gets back inside the ship with the sample when the ship starts to accelerate in the wrong direction, and he sees the extreme heat melted a hole in one of the fuel tanks.
The Astrophages in the fuel tank start rushing out towards Adrian‘s carbon dioxide-rich atmosphere, and, because the Hail Mary starts spinning, Ryland gets pinned under flying equipment, stopping him from righting the ship. As Rylan thinks he’s gonna die, suddenly Rocky pulls the equipment off of him, and then collapses because he can’t survive in Ryland‘s environment.
As quickly as possible, Rylan rights the ship and then ties ropes to Rocky to drag him back to the airlock between their two environments. Pulling up the airlock, Ryland shoves Rocky back into his own environment, hoping he can heal himself. The high-pressure gas shoots out and burns Ryland‘s left side, so the robot arms sedate him while trying to heal his wounds.
Chapters 21-22
After a few days of Ryland healing, Rocky wakes up still moving slowly, and they start making a box to keep their sample in. After looking at it under the microscope, Ryland sees an amoeba like organism that eats Astrophages, so they begin isolating that for experiments. Then, Ryland remembers that nine days before launch the third astronaut for the mission, Martin DuBois, and his back-up, exploded in an experiment with Astrophages.
When the power suddenly goes out in the ship, Ryland figures out that the amoeba has spread through the leaks in his ship and has eaten all his Astrophage fuel. With Rocky helping him to see, Rocky gets the generator to repair it and seal it off, while Ryland goes out to get the four tiny beetle ships stored in the nose of the ship. The four beetles were meant to be sent back to earth alone with Ryland’s information, so Rocky and Ryland are going to use that fuel to power the ship back to Rocky ship.
Chapters 23-24
Suddenly, Ryland remembers that five days before the Hail Mary’s launch Stratt tells him he’s the only one qualified and ready to be the third astronaut on the mission. When Ryland refuses to go because he doesn’t want to die, Stratt forces him by sedating him for the launch and giving him an amnesia drug to forget that he was forced into this suicide mission. Ryland decides he can’t do anything about it now unless he gets back to Earth, so he starts experimenting on the amoeba, Taumoeba, while Rocky fixes the ship.
Through the experiments, Ryland discovers that nitrogen kills Taumoeba. Because Venus and the planet from Rocky’s Eridani system both have a small percent of nitrogen in the atmosphere, they start slowly breeding nitrogen-resistant Taumoeba.
Chapters 25-26
It takes a few weeks, but they breed the Taumoeba to live with nitrogen. Rocky also makes Ryland two extra fuel tanks and fills them with enough Astrophages to get home. Ryland and Rocky are both sad to leave each other, but now have everything to save their planets after Rocky builds Taumoeba farms for each of them.
After saying goodbye to Rocky, Ryland starts cataloguing everything that’s happened. When he goes to feed his Taumoeba a month into his journey, he smells dead Astrophages in his supply and knows he has a Taumoeba leak again.
Chapters 27-29
After a lot of experimenting and cleaning his ship, Ryland figures out that the nitrogen resistant amoeba also developed the ability to get through the xenon material that Rocky uses to build everything. Luckily, the four mini beetle ships have some of the Taiba in steel containers, so they can be cut open back on Earth. As Ryland gets rid of all the xenon containers for the Taumoeba, he realizes that Rocky‘s whole ship is made out of it, so the Taumoeba will eat all of his fuel to get home.
Ryland decides to launch the four beetles containing the Taumoeba back for Earth, and he turns around to search for Rocky’s ship knowing he’ll never have enough food to make it back to Earth. After some trial and error of searching, he finally finds Rocky ship, and after they disinfect Rocky with nitrogen, Rocky gets on the Hail Mary to fly them back to Rocky‘s planet. Rocky doesn’t want Ryland to die, and figures out that Rylan can eat the Taumoeba.
16 years later, Ryland still lives on Rocky’s planet in a large bubble they’ve built with his environment, and they’ve figured out how to make the Taumoeba into different foods with the vitamins he needs in it. Since they still see each other most days, Rocky comes to tell him that Eridian scientists have confirmed that the sun is back to full brightness, so the beetles Ryland sent back saved earth. Rocky offers again to send Ryland back to earth, but Rylan thinks he’s too old to make the journey and is content being a teacher for kids on Rocky’s planet.
Read My Full Book Review
Now that you’ve been reminded of the main plot points of the book, read my full book review here. Read all about what to read next, my thoughts on the end of the book, and my favorite parts of the book.
