In "Packing for Mars: The Curious Science of Life in the Void," Mary Roach examines the complexities and oddities of human space travel. She explores the physical and psychological challenges astronauts face in a zero-gravity environment, highlighting the unique experiments conducted to prepare them for life in space. This includes intriguing studies on bodily functions and the impact of space on human behavior.

Roach's use of the phrase "Experiments with Human Subjects" provides a stark reminder of the ethical considerations in scientific research, echoing troubling historical associations. By discussing these experiments, she emphasizes the lengths to which scientists go to ensure astronaut safety and mission success, while also addressing the ethical implications of testing on humans, making her narrative thought-provoking and engaging.