Human waste can produce enough bio-gas (mixture of methane and carbon dioxide). According to a study by researchers at the University of Florida (UF), this bio-gas can be used to power the rocket that will help get the astronauts back to Earth.
The study has been published in Advances in Space Research. The study finds that by optimising waste digester technologies — stirring, temperature control, organic loading rate and reactor design — methane production can be improved substantially.
Pratap C. Pullammandappallil, associate professor of agricultural and biological engineering at UF and an author of the study, said that the method is a modification of an earlier design for an anaerobic (oxygen-free) digester to manage waste at a planned base on Mars.
Pullammandappallil said, “Since the physical characteristics of waste from the lunar mission are different, the engineering design incorporated into the fermentation vessel (anaerobic digester) was also different. Anaerobic digestion is a biochemical process mediated by a mixed group of naturally occurring microorganisms that convert organic matter to biogas (typically 50-60 per cent methane and rest carbon dioxide) at near ambient conditions in an anaerobic environment.”
Note that NASA is going to construct its moon station in between 2019 and 2024. This moon station will have four crew members. In a study, researchers found that a year’s worth of the some people’s solid waste could provide about 23 percent of the 1,000 kilograms of methane required for ascent engines, using anaerobic digestion. Besides, 59 percent of methane would be available from carbon dioxide produced by the digester and from life-support systems so that a total of 82 percent of fuel needed for lunar ascent could be produced from waste products. In addition, converting waste generated at the lunar station into fuel would also save on extra weight for the lift off from Earth.
Undoubtedly, this concept is a “good initiative.” Lets wait and see where NASA reaches finally with such concept.