What about the mission’s psychological aspect? The monotony? The loneliness?

“I’m a hardware person first,” McCauley said. She is, to be precise, a solid-propulsion systems engineer. She has the distinction of being the member of our species who has been most responsible for determining the best method to catapult humanity to Mars. In order to do so, she had to know how much weight a spaceship will carry. McCauley could estimate, down to the milligram, the mass of every nut and bolt, every antivortex baffle and cargo-bay door. But how many corn tortillas and yogurt packets will four astronauts, under psychological duress, consume in 378 days? That question, or some version of it, was what McCauley needed answered. She also needed to know how much clothing they’ll need. Clothes are heavy.

Mathias, the isolation historian, was not surprised to learn that the psychological questions were a secondary consideration for NASA. But his skepticism about CHAPEA went further. Mathias questioned whether any experimental rationale could justify yet another isolation study. “I wonder if the scientific value of these simulation experiments is beside the point,” he said. The experiments, instead, seemed to him “a way of willing the colonization of Mars into being. A form of wish fulfillment — or cosplaying, to put it less poetically. This is about satisfying an urge. There seems to be a compulsion to keep repeating these fake Mars missions until we actually do it. There’s something very beautiful about this idea, but also very macabre at the same time.”

The analogue experiments reflect the utopian promise of our Martian future. For a human mission to Mars is not the highest ambition of the space program. It is just the beginning, a small step for mankind before the giant leap of planetary colonization.

Five months before CHAPEA’s call for applications, Dennis Bushnell, then chief scientist at NASA Langley Research Center and a nearly 60-year veteran of NASA, published “Futures of Deep Space Exploration, Commercialization and Colonization: The Frontiers of the Responsibly Imaginable.” Martian colonization has always been imaginable, particularly to this nation of colonizers. But in his paper Bushnell noted that the prospect has in recent years “moved from extremely difficult to increasingly feasible.” Colonization has also become increasingly desirable, because of “possibly existential societal issues, including climate change, the crashing ecosystem, machines taking the jobs, etc.” — the et cetera perhaps reflective of the obviousness of planetary decline.

A more surprising aspect of the paper is Bushnell’s prediction for how the physical hostility of Mars will be overcome: Colonists will “morph into an altered species.” He cites projections that suggest that “travelers that colonize Mars will, over time, due to the reduced g and radiation exposure, evolve into Martians.” The ultimate promise of NASA’s Mars mission is the chance to begin again — if not, exactly, as human beings, then as Martians.