The Case for Sending Women to Mars

Because women are smaller than men, they’re cheaper to send into space

Astronaut Mae Jemison in the Spacelab in 1992. Photo: NASA/Roger Ressmeyer/CORBIS

Sending more women and fewer men into space could be an economic boost for NASA and private space-going companies, Kate Greene reports for Slate.

Last year, Greene took part in a NASA study in Hawaii in which she and five other people lived on a volcano in a small dome—the equivalent of housing that might someday be installed on Mars. They were only allowed to exit if they were wearing full space suits. While there as a reporter, Greene decided to conduct an experiment. 

Using a sensor armband, she tracked the daily caloric expenditure of all the crew members. She soon noticed that women consistently burned fewer calories than men, sometimes on the order of 1,475 to 3,450. Women also ate less than men. When all food must be shipped from Earth or carefully grown on site, Greene thinks, this could make a difference for mission costs. As she writes: 

The more food launched, the heavier the payload. The heavier the payload, the more fuel required to blast it into orbit and beyond. The more fuel required, the heavier the rocket becomes, which it in turn requires more fuel to launch.

Greene is not alone in this thinking. Alan Drysdale, a systems analyst in advanced life support and a former contractor with NASA, supports the idea of selecting for astronauts with smaller body sizes, including women. According to some figures Drysdale crunched, the smallest women in the NASA program require half the resources of the largest men, Greene reports. "There’s no reason to choose larger people for a flight crew when it’s brain power you want,” he told Greene. 

As Greene acknowledges, an all-female mission to Mars, however, would be biased, since it intentionally neglects half the world's population (plus all non-petite-size women). Even if it is significantly cheaper, that would be a hard sell. "Then again," she writes, "space-mission design has always been biased in one way or another."

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