The Hail Mary is the spacecraft used by Ryland Grace to travel to Tau Ceti and find a way to get rid of the astrophage contaminating Earth's sun, Sol. It is an Astrophage-powered craft, using 1,009 spin drives for propulsion.
Outer Appearance[]
The Hail Mary is divided into two main sections: the upper section, (crewed compartments) and the lower section, (fuel/ engines). At its aft, it has 3 cylindrical fuel tanks, each with 3 sections of their own, for a total of 9 sections. At the rear of each cylinder are spin drives. While it is never explicitly stated in the book, it can be safely assumed that there are about 16 spin drives used for fine maneuvering on the lower and upper section, for a total of 32 maneuvering spin drives. (Four clusters of four thrusters, like the Apollo CSM.) There is an adapter which smoothly connects the lower section to the crew compartment, which is a cylindrical tower construction. At its tip, there is an isolated compartment which houses four smaller beetle craft, to bring data home to Sol.
Its crewed section is divided into 4 main compartments; Storage, Dormitory, Lab and Control Room.
Crew Area - Storage[]
The is the small space between the crew compartment and the engine compartment in the Hail Mary. The storage area is approximately 1 meter tall and only has one access panel from the dormitory. The floor of the storage area has 6 access panels to access various parts of the ship, including the power generators.
Crew Area - Dormitory[]
The dormitory is the next section of the crew compartment. This is a rounded room with 3 oval beds attached to the walls within reach of the "nanny bot" arms to take care of the three crewmen as they were in the coma for the duration of the trip from Earth to Tau Ceti. The height of the room is 10ft. in the ceiling is a hatch to the next section of the crew compartment. The floor contains an access hatch to the storage area under one of the crew beds.
Crew Area - Lab[]
The lab is the room after the dormitory. This room is equipped with all manner of scientific equipment including various microscopes, spectroscopes, and instruments, Also included is a 3D printer. In the center of the room is a table with chairs that are affixed to the floor. The walls are lined with additional storage for a variety of scientific and engineering tools and equipment. The entire ship is equipped with wifi and the computers can access the entire catalogue of human knowledge.
Crew Area - Control Room[]
The control room is at the front of the ship in the nose. The ship has slanted walls to match the conical shape of the front of the ship. The control room has two airlocks with windows but there are no windows in the front of the ship. The control room has a variety of monitors with the center monitor being the largest. Each monitor has the ability to display any of the ships functions, for redundancy. There is one pilot's chair in the center of the monitor area.
Artificial Gravity[]
The Hail Mary is able to generate artificial gravity 2 ways.
The first is only viable for long periods while the ship is in transit, continuously pushed by its spin drives. The spin drives accelerate the ship at 1.5 g for the first half of the trip and then flips 180-degrees to decelerate 1.5g for the second half of the trip. Ryland Grace woke up shortly before the ship was finished slowing down at the Tau Ceti system, and figured out he was in space from the higher-than-normal gravity, as no methods on Earth could feasibly produce such gravity for so long.
In the second method, the upper and lower sections disconnect, connected by cables which unspool providing clearance between the two sections. Using RCS spin drives, the ship "spins up" and the crew compartment rotates 180 so centripetal force will pull them toward the floor. Because the 2 sections are connected by non-rigid cable, a set of RCS thrusters would be necessary on each section.
Artificial gravity was discovered to be necessary for the science instruments, since it was designed for use in 1 g on Earth. Equipment for use in zero g would be new and relatively untested. The first priority was be well-tested, functioning equipment and making a centrifuge was deemed less of a technological risk than entirely new hardware.
Note on the illustration: There is an image in circulation which shows the fuel section of the HM as being 75% of the length. This is incorrect and is a result of a misinterpretation, thinking that mass was instead length.