The first crewed mission to Mars should be all female

Men have crewed every mission to the Moon so far, but when we finally send humans to Mars it would be wise to send only women — at least at first.

Mind you, this wouldn’t primarily be for fairness — a correction for the rampant sexism that denied American women the title of “astronaut” until Sally Ride‘s historic flight in 1983 — but rather a practical decision based on calculations as cold as deep space. Available evidence bluntly suggests that women would be more efficient and capable crewmembers on long-duration missions away from Earth.

Dr. W. Randolph Lovelace II and Brigadier General Don D. Flickinger, the former chair and vice chair of NASA’s Special Committee on Life Sciences, originally made the pragmatic case for female astronauts in the late 1950s. The duo noted that women are lighter and thus require less oxygen; they have fewer heart attacks; their reproductive systems are less at risk from radiation. Of course, Lovelace and Flickinger were overruled amid the era’s prevailing sexism.

NASA scientist Geoffrey Landis reiterated the argument in 2000, applying it more strictly to deep-space flight, where the only resources available are the ones you take with you.

“Women are on average smaller than males: women use less oxygen, consume less consumables, produce less carbon dioxide. They have lower mass and take up less volume. The argument for an all-female crew is simple: such a crew would require considerably less support… and allow a smaller spacecraft. This would produce a considerable savings in cost,” he wrote.

Long-term space missions

A recently published study put some concrete numbers behind Landis’ contentions. Scientists with the Space Medicine Team at the European Space Agency calculated that the average female astronaut requires 26% fewer calories, 29% less oxygen, and 18% less water than the average male. This translates to some sizeable resource savings. A 1,080-day space mission crewed by four women would need 1,695 fewer kilograms of food compared to an all-male mission. That’s about 10% of a SpaceX Falcon Heavy rocket’s payload to Mars — valuable space which could be filled with additional scientific projects and equipment to ensure a safe and successful mission.

Beyond physical practicality, there are psychological reasons women might be better suited to extended missions away from Earth.

“Statistics show that all-woman groups are far more likely to choose non-confrontational approaches to solve interpersonal problems, and most definitely are more likely to deal with a situation without resorting to violence, which could be a big problem on a Mars journey, where the crew must live in close quarters for 2-3 years,” Landis wrote. “Numerous sociological studies have shown that women, in general, are more cooperative, and less given to hierarchical social structures.”

Just over 60 years ago, the Women in Space Program put 19 female aviators through astronaut training, with more onerous testing than NASA gave to the original Mercury 7 astronauts. The 13 women who passed arguably topped the men both physically and psychologically. The first crewed mission to Mars, which will likely not occur until 2029 at the very earliest, will require every advantage possible, so it only makes sense that an all-female team should be the first to step onto the red planet.