Microbe turns space waste into electricity

摘要

The prospect of sending astronauts to Mars requires a thoughtful look at one unavoidable aspect of space travel: What is to be done with the waste products that accumulate during a long trip? One answer would be to jettison the material into space, just as ships once disposed of their garbage on the open ocean. However, there is another requirement in space―namely, the need to recycle every drop of moisture. In much the same way that a land-based sewage disposal plant will process waste products to a point where the fluid can be sent into a river without spreading. disease, so too will a space-based processing system do the same for the astronauts. However, because there are no rivers in space, the moisture processed would be recycled as drinking water. Moreover, NASA scientists are certain that the water produced from such a system would be safer to drink than the water that comes from one's tap at home. Not content with merely providing safe drinking water from waste products, NASA-supported researchers are also working to develop a fuel cell that can extract electricity from human waste. According to one estimate, on a two-year trip to Mars, a crew of six will generate more than six tons of unwanted solid or-ganic material―much of it human waste.