Project Hail Mary is the latest sci-fi novel by Andy Weir. MGM has scheduled its release for the eponymous movie starring Ryan Gosling on Friday, March 20th. Having hastily read the book I offer a brief summary of the story and its premise, hoping for a faithful screen adaptation. It should be noted that, by necessity, Weir engages in literary exposition. For awareness, note that conditions described in the book may not be easily analogized to terrestrial-bound readers, as much of the physics and chemistry referenced in the novel could potentially be unfamiliar to those without relevant STEM training.

The novel begins with the adult male protagonist awakening from an induced coma, having forgotten both his identity and the details of his specific mission. Gradually, through memory flashbacks, he eventually comes to recognize both his surroundings and his purpose. Aboard an interstellar spacecraft, he is decelerating towards Tau Ceti – a yellow star twelve light-years from our sun (named Sol in the book) and of a size that is slightly smaller.

Eventually, we learn that his name is Ryland Grace – a molecular biologist whose post-doctoral academic reputation abruptly disintegrated back on earth after he asserted that life could develop sans water and carbon. So now he teaches at a junior high school in San Francisco, but is eventually summoned by Belgian administrator Eva Stratt to assist in studying a recent and alarming phenomenon – Sol is unexpectedly dimming at an alarming rate. These changes have been evidenced by various robotic probes that have been monitoring the solar darkening and collecting samples of particles that are thought to be causing these changes. The particles exhibit behavior of microscopic organisms and absorb tremendous quantities of energy. They re-radiate at an infrared wavelength at 7.84 micrometers, referred to as the Petrova Line, which corresponds to blackbody radiation temperature of 369.56 Kelvin (a few degrees below water’s boiling point at sea-level pressure).

Researchers call the organism “Astrophage” – which we learn is essentially a form of stellar mold. Grace ultimately is able to discover its composition and how such cells reproduce. He discerns that Astrophage microbes gather energy near the solar photosphere, and upon reaching a threshold quantity, a cell immediately migrates to Venus for mitosis (cellular division) capturing carbon dioxide from the planet’s upper atmosphere. Between the sun’s energy and the Venusian atmosphere, the Astrophage propagate rapidly. Their unimpeded growth is reducing the solar radiation that earth receives, thereby posing a threat to earth’s continued existence.

Meantime, Stratt informs Grace that amateur astronomers have discovered several neighboring stars that also exhibit diminution in luminescence. The exception to this degradation appears to be Tau Ceti, so governments – mindful of human population collapse from an impending ice age – cooperate to desperately construct a spacecraft, aptly named the Hail Mary, for travel to this star. They have hopes that by some “miracle,” they can learn why that such catastrophe has been averted there and report the findings. Neighboring stars referenced above are shown in the map below.

Based on Grace’s findings, various laboratories around the world engage in growing Astrophage in order to provide mono-propellant for spin drives on the Hail Mary, which would then accelerate halfway towards Tau Ceti, and then decelerate on approach. Both thrust operations induce artificial gravity, while approaching light speed reduces relativistic elapse time-rate and thereby slows the aging process. Intended as a one-way trip, the Hail Mary’s bow encloses four “beetle” pods named John, Paul, George and Ringo, with the intended purpose of returning samples and collected information back to earth for a solution to address the Astrophage.

Because psychology experiments have revealed that aboard cramped confines multiple humans on board would turn aggressive against each other, extended sleep becomes necessary until reaching the intended destination. However, only a tiny portion of the population can tolerate this induced coma, with Dr. Grace being one of them, along with two others; a Chinese commander and a Russian specialist, neither of whom survives the trip due to a life-support malfunction that goes unresolved.

The Hail Mary vehicle comprises habitable and propulsion segments. Upon arrival, these portions separate, while remaining connected by cables. The elongated ship configuration initiates spin to induce centrifugal force for simulating gravity, implicitly by yaw and/or pitch thrusters. This technique was also demonstrated in the movie Stowaway (2021), which involved a commercial supply voyage to Mars. For the Hail Mary’s in-homogeneous mass distribution, the cables anchored on the segments’ peripheral rims remain vulnerable to tangling.

Upon reaching the vicinity of Tau Ceti, Grace encounters a much larger and strange vessel that rendezvous with Hail Mary. Grace names this alien ship Blip-A, and reverses his thrusters in order to negate spin. They initiate communication by exchange of items in a canister, followed by Blip-A constructing an airlock tunnel to span between the ships for allowing mutual contact aided by gestures and sounds. Grace names the alien that he encounters “Rocky.” The creature is a refractory ceramic being with a half-meter-wide pentagon core, accompanied by five jointed limbs equipped with fingers and claws. Rocky’s ship originated from 40 Eridani – sixteen light years away (in roughly the same direction as Epsilon Eridani), so in the interest of convenience, Grace names Rocky’s home planet “Erid.” Erid has eight times earth’s mass and an order-of-magnitude denser atmosphere composed of ammonia (NH₃). Grace comes to learn that Rocky communicates by musical tones while counting in base-6, and appears to navigate by sound rather than sight.

Communication with aliens has been previously explored by Hollywood in the films Contact (1997) and Arrival (2016). In addition, Star Trek introduced mineral based lifeforms to television with the episode “Devil in the Dark,” and again in The Next Generation (and nobody should forget the fabulous rock monster from the comedy movie Galaxy Quest). Grace learns that although Eridians are resourceful and resilient, their native environment protects them from cosmic radiation. So despite their impressive technology, their ignorance about radiation sickness has struck down their crew from almost two dozen to only a single survivor, who was lucky enough to be shielded by the Astrophage in aft propellant containers. In the film, Eridians hydraulic and pneumatic musculature, mercury circulation, and metal skeleton are protected by a mineral exterior. Excitedly curious about the Hail Mary, Rocky encapsulates itself in a xenonite geodesic ball using Astrophage for temperature regulation so that he can board Grace’s ship.

Rocky and Grace navigate the Hail Mary to alter course towards a planet they named Adrian that is orbiting Tau Ceti. They construct an environmental sample collector out of construction material brought from the Blip-A so that Adrian to reach an atmospheric depth that is below safe orbital altitude. Interestingly, thirty years ago on STS-75, Space Shuttle Columbia did something similar when it extended a twelve-mile-long tether for electric field measurements. While retrieving the sample, the Adrian atmosphere’s reaction melts a hole in the propulsion portion leaking Astrophage, producing unintended unsymmetrical thrust. They jettison two of the nine aft containers, but the yaw from being off-axis forces causes the Hail Mary to spin, trapping Grace and Rocky by centrifugal forces. Described in harrowing detail, Rocky risks his life to save Grace, and Grace returns the favor.

Following partial recovery, Grace studies the environmental sample to find an Astrophage predator beetle that he names “Taumoeba,” some of which unexpectedly migrates into the propellant tanks and shuts off power. Grace removes three of the beetles as replacement thrusters for return to the Blip-A for replacement Astrophage fuel. As Rocky recovers, Grace discovers that nitrogen (N₂) is toxic to native Taumoeba, negating its use on Venus or at Tau Ceti. So therefore, Grace begins to selectively breed resistant cells. Meantime, they discover that Taumoeba infiltrate about the Hail Mary to feed, which necessitates nitrogen purges in these spaces.

After joining the Blip-A and refueling the Hail Mary, Rocky and Grace set off on their respective return journeys to bring nitrogen-resistant Taumoeba to their homeworlds, and in order to save their people. Along the way, Grace detects escape of Taumoeba and eventually realizes that these microbes can void nitrogen purge by permeating xenonite. Alarmed that the Blip-A is primarily composed of this exotic material, Grace releases the refurbished beetles to Sol and alters course towards Rocky’s last known heading.

Eventually, Grace finds the Blip-A, albeit a dead hulk, and uses it to rescue Rocky who boards the Hail Mary, much relieved. Together they reach Erid and save the planet. Years later, Rocky assures Grace that Sol has also been restored to its prior brightness. Grace then travels on and eventually finds himself teaching a class of juvenile Eridians.

Reflections on the Science and the Story

In science fiction stories, one can reasonably ask about plausibility. Two preconditions necessary to the story include: first, the ability of Astrophage’s opaque shell to trap neutrinos, and second, the alien ability to synthesize stable inorganic compounds from a chemically inert Noble gas such as xenon (Xe). The first seems quite implausible, but is necessarily required to enable confined elementary particle decay for energy storage within a cell membrane. Unexpectedly, the second is actually plausible based on an analogous achievement almost seven decades ago. Much less likely, Weir takes for granted humanity’s ability to discover how to consume Astrophage for propulsive energy release, as well as international cooperation.

Of course, almost everyone would agree that the most outrageous demand for suspension of disbelief by viewers is accepting that Dr. Grace would ever be permitted to teach junior high school students in San Francisco! In fact, we know that this is a place where algebra instruction “goes to die.”

Also in the first chapter, Grace, not yet remembering his identity, is interrogated by an onboard computer with trivial arithmetic queries, one of which being the cube root of eight. Grace whimsically responds with “two times e to the two-i-pi,” which the computer rightfully rejects. Assuming Grace intended his answer to relate to Euler’s formula e^iπ+1=0, with values e as the natural number (approximately 2.718), i as the imaginary number √–1 and π as the ratio between circumference and diameter, his response should have been “minus two times e to the i-pi,” instead. Either the proof-reader didn’t notice the discrepancy, or perhaps the author merely sought to reinforce the reader’s understanding that having just woken from an induced coma, Grace’s mind remained confused and his recollection impaired.

Weir’s latest novel is a story of redemption. While Grace presents a sympathetic and nominally pleasant character, Stratt recognizes him to be timid beyond his comfort zone of expertise – and outside the classroom where he remains the knowledgeable authority. By the novel’s end, Grace sacrifices his ability to return to earth, and even expects to perish after arrival at Erid for lack of nourishment. He endures, however, thanks to the ingenuity of Erid’s grateful inhabitants.

Grace (involuntarily) trades his comfort and familiarity to become an unwitting hero of two worlds by accepting an awesome responsibility, and together with his new partner Rocky, methodically tackles each obstacle that they encounter. The cooperative pair become greater than their individual selves, and in so doing serve as the cornerstone (Psalm 118:22) on which to establish salvation. Perhaps most of us might expect to decline such honor, but Project Hail Mary serves as an inspirational tale nonetheless.

Despite my typical reluctance to read fiction, Project Hail Mary served as an enjoyable way to pass the time. We can only hope that the cinematic rendition will be equally worthwhile.

Photo Credit- the bibliophile.