WEBVTT - Could Human Waste Feed Astronauts? 0:00:02.040 --> 0:00:06.920 Welcome to brain Stuff from How Stuff Works, Hi brain 0:00:06.960 --> 0:00:09.800 Stuff Lauren Vogel bomb here. A manned mission to Mars 0:00:09.880 --> 0:00:12.479 might take around six months. Suffice it to say, when 0:00:12.520 --> 0:00:15.920 meal times roll around, astronauts won't be dialing up delivery 0:00:15.920 --> 0:00:20.000 pizza and root. Instead, they may be eating nutrition derived 0:00:20.079 --> 0:00:22.800 from their own fecal matter, a concept that would save 0:00:22.840 --> 0:00:26.280 on cargo, space and wait while maximizing materials already found 0:00:26.320 --> 0:00:30.120 on the spacecraft. At Penn State University, scientists are developing 0:00:30.120 --> 0:00:33.120 a system that leverages certain types of microbes that convert 0:00:33.360 --> 0:00:37.800 human solid waste into protein and fat Latin foods. Researchers, 0:00:37.840 --> 0:00:40.440 for better or Worse, have already called the result a 0:00:40.479 --> 0:00:44.280 microbial goo that's sort of reminiscent of vegemite, a comparison 0:00:44.280 --> 0:00:48.760 that seems unlikely to please vegemites corporate executives. Because it's 0:00:48.760 --> 0:00:51.960 difficult and time consuming to grow food in space, astronauts 0:00:51.960 --> 0:00:55.160 have to rely on items in their closed environment. The 0:00:55.240 --> 0:00:58.440 lynch pin of the system is anaerobic digestion, which can 0:00:58.480 --> 0:01:01.400 break down certain materials with the need for oxygen. It's 0:01:01.400 --> 0:01:05.280 a common process for reducing municipal waste on Earth. In tests, 0:01:05.400 --> 0:01:09.520 the digestion process produced methane gas. That gas turns out 0:01:09.560 --> 0:01:13.319 to be useful in growing a microbe called Methylococcus capsulattice, 0:01:13.400 --> 0:01:16.160 which is already used for animal feed pellets and contains 0:01:16.160 --> 0:01:20.399 about fifty protein and thirty six percent fat content. According 0:01:20.400 --> 0:01:23.360 to the National Academy of Sciences, humans function best when 0:01:23.400 --> 0:01:27.800 they ingest nutrition with about fifty percent carbohydrates, twenty percent fat, 0:01:27.880 --> 0:01:31.720 and ten to thirty protein, So the goose still has 0:01:31.720 --> 0:01:33.400 a ways to go before it can count as an 0:01:33.440 --> 0:01:37.440 ideal food source. The tests relied on substitute liquid and 0:01:37.480 --> 0:01:40.520 solid waste instead of actual human wastes. When the real 0:01:40.560 --> 0:01:43.320 thing is introduced, there will also be concerns about pathogens 0:01:43.360 --> 0:01:46.600 that could cause illnesses. That's where tweaking the pH levels 0:01:46.600 --> 0:01:50.400 and or temperatures may help. Tests showed that by increasing 0:01:50.400 --> 0:01:52.680 the system's temperatures to around a hundred and fifty eight 0:01:52.680 --> 0:01:56.480 degrees fahrenheit that's seventy degrees celsius, most germs were eliminated, 0:01:56.720 --> 0:02:01.960 yet the nutritious microbe Thermois aquaticus survived. Alternately, they raised 0:02:02.000 --> 0:02:04.920 the alkalinity of another batch and found that bacteria called 0:02:05.000 --> 0:02:09.000 halo Monus deciderrata still managed to proliferate, while germs did not. 0:02:09.880 --> 0:02:13.240 The team borrowed concepts from commercial aquarium filters that use 0:02:13.320 --> 0:02:17.240 fixed film filters to neutralize fish waiste. The filters incorporate 0:02:17.280 --> 0:02:20.520 a bacteria laden film and were adapted by researchers to 0:02:20.560 --> 0:02:24.480 accommodate methane production. The result solid waste can be treated 0:02:24.480 --> 0:02:27.240 in a matter of hours instead of days plus. Because 0:02:27.280 --> 0:02:30.200 the system is self contained, it really doesn't require much 0:02:30.240 --> 0:02:34.880 babysitting other than you know, the necessary inputs. But there's 0:02:34.919 --> 0:02:38.200 also the matter of taste. Lisa Steinberg, the lead author 0:02:38.200 --> 0:02:40.600 on the study, says that the bacteria could be mixed 0:02:40.639 --> 0:02:43.440 with other materials and flavorings to make it more palatable. 0:02:43.840 --> 0:02:46.200 She said in an email, it's nearly certain that there 0:02:46.200 --> 0:02:48.919 would be plants grown in conjunction with this food stuff, 0:02:48.919 --> 0:02:52.720 which would provide additional flavors and textures. And what about 0:02:52.720 --> 0:02:56.480 the potential psychological issues associated with consuming a material of 0:02:56.560 --> 0:03:00.760 such dreary origins, Steinberg said. Astronauts ready have to drink 0:03:00.800 --> 0:03:03.840 their own processed urine, so they're probably accustomed to things 0:03:03.880 --> 0:03:07.520 being done differently in space than on Earth. Some astronauts 0:03:07.520 --> 0:03:10.280 on the International Space Station do already recycle some of 0:03:10.320 --> 0:03:13.119 their urine. Poop, on the other hand, has a more 0:03:13.200 --> 0:03:17.040 spectacular ending. It's blasted into space, caught an Earth's orbit, 0:03:17.160 --> 0:03:21.079 and then burns up like a shooting star on reentry. Yes, 0:03:21.360 --> 0:03:24.799 in space, poop has historically been a problem. Maybe now 0:03:24.840 --> 0:03:27.560 poop will be part of the solution. While these still 0:03:27.600 --> 0:03:31.440 experimental concept may not exactly fire up astronauts appetites, it 0:03:31.520 --> 0:03:34.480 may eventually provide sustenance to space explorers who have a 0:03:34.520 --> 0:03:43.120 limited buffet options among the stars. Today's episode was written 0:03:43.120 --> 0:03:46.040 by Nathan Chandler and produced by Tristan McNeil. For more 0:03:46.080 --> 0:03:48.400 on this and lots of other tasty topics, visit our 0:03:48.400 --> 0:04:02.040 home planet, how stuff Works dot com.