Packing for Mars: The Curious Science of Life in the Void is one of several bestselling nonfiction works by science writer and humorist Mary Roach. Published in 2010, the work focuses on the human side of space travel and offers behind-the-scenes accounts of peculiar and taboo topics such as sex, vomit, and toilets in space. Roach writes from a candid, outsider’s point of view and demystifies some of the grandeur of space travel by reporting on the psychological and physical burdens of an astronaut’s job.

Roach’s thesis is that space travel reveals just as much about human nature as it does about the cosmos. By describing humanity’s attempts to explore and survive in extreme environments, Roach celebrates how ingenuity and absurdity coexist to achieve the monumental and the mundane. In 2022, Roach published an adaptation geared for a younger audience entitled Packing for Mars for Kids.

This guide references the 2011 W.W. Norton & Company Kindle edition of the original title.

Summary

Packing for Mars: The Curious Science of Life in the Void details in 16 chapters that space travel is no easy task. For author Mary Roach, exploring space is as much a psychological, physiological, and social feat as it is an engineering one.

In the Prologue, Roach contends that humans are more vulnerable and unpredictable than machines. Little victories and lesser-known surreal stories about space exploration garner her attention and respect. The book focuses on the peculiarities and triumphs of human exploration in the extreme environment of space, and the perhaps even stranger environment of space simulations. Roach finds humor and inspiration in all the ways scientists have grappled with keeping humans alive in a hostile and sterile environment with no oxygen, gravity, sex, food, toilets, or privacy.

The first quarter of the book addresses the psychological impact of space travel, particularly the effects of confinement and isolation. Roach reports on isolation chamber experiments in Japan, where finalists folded origami birds, and in Russia, where a fist fight and sexual harassment incident occurred. The studies illustrated the importance of cooperation, empathy, and the ability to endure boredom for astronauts. In contrast to the earlier era of macho pilot astronauts, space shuttle crew members have mostly been scientific researchers who participated in longer missions and benefited from having congenial colleagues.

Roach focuses on the social and mental health of astronauts who spent weeks and months in cramped spaces with few outlets to relieve stress. Sleep deprivation, depression, and frustration were common psychological concerns, while the effects of low gravity on breathing, heart-rates, vision, and digestion were physical challenges. Roach describes the emotional impact of being in space: Some astronauts experienced an overwhelming sensation of awe called “space euphoria,” while others encountered an uncomfortable and existential apprehension of the expanding universe.

In subsequent chapters, Roach deals with the mechanics of low gravity and excessive gravity on the human body. In low gravity, astronauts struggle with motion sickness and vomiting, as well as visual disorientation that makes it difficult to discern up from down. While an astronaut is unlikely to die from vomiting in a space helmet because of the system of valves and ducts to expel the material, aspirating vomit or having one’s vision compromised by the mess could be a danger. Roach also describes her experience on a C-9 aircraft performing parabolas. Parabolic flights provide simulations of zero gravity and doubled gravity, allowing researchers to test out how new equipment will function in space. To study the impact of stronger G-forces, NASA conducted crash tests with cadavers and modeled some of the space capsule’s restraint features on race car seat designs.

Roach also devotes a portion of her book to bodily functions in zero gravity. She struggles to find any evidence that sexual intercourse has taken place in space, though she finds an abundance of research on personal hygiene, food, and waste management. Scientists have experimented with how long an astronaut could comfortably wear a spacesuit without showering or bathing, how to develop crumb-less food that would produce “low-residue” excrement, and how to dispose of body waste with adhesive plastic bags or vacuum-suction toilets. Roach emphasizes that the novelty of space-age technology also needs to consider an astronaut’s morale and need for comfort. There is a balance of the foreign and familiar: Food served in tube- or pellet-like form felt dehumanizing for astronauts, but an innovation like drinking reclaimed urine is a necessary and accepted practice.

Roach celebrates the astronauts, scientists, and volunteers who have participated in sometimes surreal-sounding studies to ensure the safety of space exploration: Researchers at the Haughton-Mars Project practiced timed simulations in the desolate Canadian Arctic landscape to test new technologies and strategies for Moon and Mars missions; volunteers at the Flight Analogs Research Unit in Texas remained in bed for three months so scientists could study bone loss; and a professional BASE jumper trained to free-fall from space to test a pressurized escape suit. Roach marvels at the dedicated minds and bodies of those who help make space travel safe and possible.