Project Hail Mary

In flashback, Grace watches the launch of the final pieces of the Hail Mary, which is being assembled in orbit by the International Space Station crew. DuBois notes that it’s good to have Grace there as a representative for Stratt, and Grace realizes that he is considered Stratt’s second-in-command and the first officer of Project Hail Mary.

In the present, in the Hail Mary lab, Grace is unable to identify an Astrophage predator among the alien life forms in the sample of Adrian’s upper atmosphere. Rocky hypothesizes that the predator may only live lower in the atmosphere, where the greater concentration of carbon dioxide creates the ideal Astrophage breeding altitude. Using trigonometry and observation, Grace determines the exact breeding altitude of Astrophage on Adrian, but it is too low for the Hail Mary to travel to without falling out of orbit or burning up in Adrian’s atmosphere.

Grace dreams up a risky plan. Rocky will build a 10-kilometer chain out of xenonite and a sampling device to “fish” for Astrophage at the breeding altitude. To drag the sampling device through the Astrophage population, Grace will have to fly the Hail Mary at a constant velocity and carefully maintained angle, thereby avoiding both falling out of orbit and accidentally vaporizing the xenonite chain with the infrared thrust of the Astrophage engine. Rocky and Grace get to work building the chain.

Grace wonders why Rocky has so much extra Astrophage to give him, and Rocky explains that the Blip-A’s journey to Tau Ceti took only three years instead of the expected six years. Grace realizes that Eridians have no concept of relativistic physics, and thus do not understand time dilation. Eridians have managed interstellar travel using only Newtonian physics and Rocky’s trial-and-error engineering.

In the past, Steve Hatch, a professor at the University of British Columbia, visits Grace’s office on the aircraft carrier. Hatch has designed four Beetle probes, each named for a member of the British rock group The Beatles, using Komorov’s spin drive technology. The Beetle probes, with no human occupants, will be able to return to Earth in just twelve Earth years, while only experiencing 20 months relative time. Hatch asks Grace if he believes in a higher power, and Hatch claims that Astrophage is God’s way of handing humanity the future via clean, renewable energy. Grace is astounded by Hatch’s optimism.

The enormous xenonite chain complete, Rocky and Grace prepare to fish for Astrophage at their breeding altitude in Adrian’s atmosphere. With no way to accurately calculate the perfect angle for flight in advance, Grace manually adjusts the flight path of the Hail Mary until it is safe to lower the chain. Meanwhile, the Astrophage-powered engine super-heats Adrian’s atmosphere. Despite warnings from the ship’s life support system about extreme temperatures, Grace puts his faith in the Astrophage cooling system to protect them, and the sample collection is successful.

Grace must undertake a spacewalk to retrieve the sample dangling from the ship while under the full effects of Adrian’s gravity. Rocky makes Grace a special winch that will simultaneously wind and dismantle the 10-kilometer chain. Rocky tells Grace to be careful as, “You are friend now” (314).

While admiring Adrian’s beauty, Grace successfully retrieves the sample with the winch. While trying to re-enter the ship, Grace is thrown to the hull when the Hail Mary suddenly veers off course. He manages to climb back through the airlock to find Rocky distressed in the control room, where the screens flash warnings. Rocky senses that the Hail Mary’s hull is warping near the fuel tanks due to the immense heat and pressure caused by Grace’s flight maneuver. Grace tries to get the ship back under control, but their velocity and gravity continue to increase. Grace realizes that there is a hole in one of the fuel tanks, and the exposed Astrophage fuel is migrating to Adrian, pushing the ship off course as the Astrophage departs. Under immense g-forces, Grace is just barely able to jettison the damaged fuel tanks before the pilot seat is torn from its anchors and crushes Grace against the monitors. Rocky leaves his pressurized compartment and rescues Grace, exposing the alien to Earth atmosphere, and Rocky falls unconscious, with smoke pouring from his radiator organ.

Afraid to turn on the spin drives before knowing the extent of damage to the ship, Grace manually engages Hail Mary’s centrifuge mode to stabilize gravity on board. Grace manages to haul a heavy and unconscious Rocky down to the dormitory from the control room, only to discover that the airlock to Rocky’s compartment was destroyed by flying debris during the uncontrolled manual transition to centrifuge mode. The lab is also in total disarray. Grace manages to return Rocky to the compartment through the broken airlock but is briefly exposed to Adrian’s atmosphere, resulting in severe burns. The robotic medical arms intubate and sedate Grace. Grace comes to a few hours later, wearing an oxygen mask and with his left arm bandaged. Grateful to be alive, he decides he has to help Rocky.

Exhausted and groggy from painkillers, Grace attempts to repair the ship, save Rocky, and examine the Astrophage sample simultaneously. Grace sets up a clumsy observation tank for the Adrian Astrophage sample, accidentally sealing it so there is no way to retrieve the sample. With more success, Grace re-orients the crew cabin and surveys the damage to the spaceship. Grace finds and patches a small leak with epoxy and asks the computer for more painkillers, which impair his judgment. He dangerously drills into the dormitory airlock and rigs a pressurized pump inside of it to blow soot out of Rocky’s radiator organ, hoping it will be enough to save him.