One of my favorite aspects of Mary Roach’s book Packing for Mars is her hilarious but thorough examination of what happens to astronauts’ bodily functions in space. Given how much these rely on gravity, microgravity is a challenge in many ways, including using the bathroom. I certainly never thought about the advantages of a toilet with a vacuum system before reading the book. But all those messy details may soon amount to more than just a funny story. NASA commissioned researchers at the University of Florida to see how human waste could be useful, and the results indicate that we may be able to make rocket fuel out of astronaut poop.
Just yesterday I was watching a nature documentary that featured small communities living in India just south of the Himalayas. They burn goat and buffalo poop, which establishes the dual purpose of maintaining a degree of cleanliness while also providing cooking and heating energy–though they’re not trying to get rockets off the ground.