1 00:00:02,040 --> 00:00:06,920 Speaker 1: Welcome to brain Stuff from How Stuff Works, Hi brain 2 00:00:06,960 --> 00:00:09,800 Speaker 1: Stuff Lauren Vogel bomb here. A manned mission to Mars 3 00:00:09,880 --> 00:00:12,479 Speaker 1: might take around six months. Suffice it to say, when 4 00:00:12,520 --> 00:00:15,920 Speaker 1: meal times roll around, astronauts won't be dialing up delivery 5 00:00:15,920 --> 00:00:20,000 Speaker 1: pizza and root. Instead, they may be eating nutrition derived 6 00:00:20,079 --> 00:00:22,800 Speaker 1: from their own fecal matter, a concept that would save 7 00:00:22,840 --> 00:00:26,280 Speaker 1: on cargo, space and wait while maximizing materials already found 8 00:00:26,320 --> 00:00:30,120 Speaker 1: on the spacecraft. At Penn State University, scientists are developing 9 00:00:30,120 --> 00:00:33,120 Speaker 1: a system that leverages certain types of microbes that convert 10 00:00:33,360 --> 00:00:37,800 Speaker 1: human solid waste into protein and fat Latin foods. Researchers, 11 00:00:37,840 --> 00:00:40,440 Speaker 1: for better or Worse, have already called the result a 12 00:00:40,479 --> 00:00:44,280 Speaker 1: microbial goo that's sort of reminiscent of vegemite, a comparison 13 00:00:44,280 --> 00:00:48,760 Speaker 1: that seems unlikely to please vegemites corporate executives. Because it's 14 00:00:48,760 --> 00:00:51,960 Speaker 1: difficult and time consuming to grow food in space, astronauts 15 00:00:51,960 --> 00:00:55,160 Speaker 1: have to rely on items in their closed environment. The 16 00:00:55,240 --> 00:00:58,440 Speaker 1: lynch pin of the system is anaerobic digestion, which can 17 00:00:58,480 --> 00:01:01,400 Speaker 1: break down certain materials with the need for oxygen. It's 18 00:01:01,400 --> 00:01:05,280 Speaker 1: a common process for reducing municipal waste on Earth. In tests, 19 00:01:05,400 --> 00:01:09,520 Speaker 1: the digestion process produced methane gas. That gas turns out 20 00:01:09,560 --> 00:01:13,319 Speaker 1: to be useful in growing a microbe called Methylococcus capsulattice, 21 00:01:13,400 --> 00:01:16,160 Speaker 1: which is already used for animal feed pellets and contains 22 00:01:16,160 --> 00:01:20,399 Speaker 1: about fifty protein and thirty six percent fat content. According 23 00:01:20,400 --> 00:01:23,360 Speaker 1: to the National Academy of Sciences, humans function best when 24 00:01:23,400 --> 00:01:27,800 Speaker 1: they ingest nutrition with about fifty percent carbohydrates, twenty percent fat, 25 00:01:27,880 --> 00:01:31,720 Speaker 1: and ten to thirty protein, So the goose still has 26 00:01:31,720 --> 00:01:33,400 Speaker 1: a ways to go before it can count as an 27 00:01:33,440 --> 00:01:37,440 Speaker 1: ideal food source. The tests relied on substitute liquid and 28 00:01:37,480 --> 00:01:40,520 Speaker 1: solid waste instead of actual human wastes. When the real 29 00:01:40,560 --> 00:01:43,320 Speaker 1: thing is introduced, there will also be concerns about pathogens 30 00:01:43,360 --> 00:01:46,600 Speaker 1: that could cause illnesses. That's where tweaking the pH levels 31 00:01:46,600 --> 00:01:50,400 Speaker 1: and or temperatures may help. Tests showed that by increasing 32 00:01:50,400 --> 00:01:52,680 Speaker 1: the system's temperatures to around a hundred and fifty eight 33 00:01:52,680 --> 00:01:56,480 Speaker 1: degrees fahrenheit that's seventy degrees celsius, most germs were eliminated, 34 00:01:56,720 --> 00:02:01,960 Speaker 1: yet the nutritious microbe Thermois aquaticus survived. Alternately, they raised 35 00:02:02,000 --> 00:02:04,920 Speaker 1: the alkalinity of another batch and found that bacteria called 36 00:02:05,000 --> 00:02:09,000 Speaker 1: halo Monus deciderrata still managed to proliferate, while germs did not. 37 00:02:09,880 --> 00:02:13,240 Speaker 1: The team borrowed concepts from commercial aquarium filters that use 38 00:02:13,320 --> 00:02:17,240 Speaker 1: fixed film filters to neutralize fish waiste. The filters incorporate 39 00:02:17,280 --> 00:02:20,520 Speaker 1: a bacteria laden film and were adapted by researchers to 40 00:02:20,560 --> 00:02:24,480 Speaker 1: accommodate methane production. The result solid waste can be treated 41 00:02:24,480 --> 00:02:27,240 Speaker 1: in a matter of hours instead of days plus. Because 42 00:02:27,280 --> 00:02:30,200 Speaker 1: the system is self contained, it really doesn't require much 43 00:02:30,240 --> 00:02:34,880 Speaker 1: babysitting other than you know, the necessary inputs. But there's 44 00:02:34,919 --> 00:02:38,200 Speaker 1: also the matter of taste. Lisa Steinberg, the lead author 45 00:02:38,200 --> 00:02:40,600 Speaker 1: on the study, says that the bacteria could be mixed 46 00:02:40,639 --> 00:02:43,440 Speaker 1: with other materials and flavorings to make it more palatable. 47 00:02:43,840 --> 00:02:46,200 Speaker 1: She said in an email, it's nearly certain that there 48 00:02:46,200 --> 00:02:48,919 Speaker 1: would be plants grown in conjunction with this food stuff, 49 00:02:48,919 --> 00:02:52,720 Speaker 1: which would provide additional flavors and textures. And what about 50 00:02:52,720 --> 00:02:56,480 Speaker 1: the potential psychological issues associated with consuming a material of 51 00:02:56,560 --> 00:03:00,760 Speaker 1: such dreary origins, Steinberg said. Astronauts ready have to drink 52 00:03:00,800 --> 00:03:03,840 Speaker 1: their own processed urine, so they're probably accustomed to things 53 00:03:03,880 --> 00:03:07,520 Speaker 1: being done differently in space than on Earth. Some astronauts 54 00:03:07,520 --> 00:03:10,280 Speaker 1: on the International Space Station do already recycle some of 55 00:03:10,320 --> 00:03:13,119 Speaker 1: their urine. Poop, on the other hand, has a more 56 00:03:13,200 --> 00:03:17,040 Speaker 1: spectacular ending. It's blasted into space, caught an Earth's orbit, 57 00:03:17,160 --> 00:03:21,079 Speaker 1: and then burns up like a shooting star on reentry. Yes, 58 00:03:21,360 --> 00:03:24,799 Speaker 1: in space, poop has historically been a problem. Maybe now 59 00:03:24,840 --> 00:03:27,560 Speaker 1: poop will be part of the solution. While these still 60 00:03:27,600 --> 00:03:31,440 Speaker 1: experimental concept may not exactly fire up astronauts appetites, it 61 00:03:31,520 --> 00:03:34,480 Speaker 1: may eventually provide sustenance to space explorers who have a 62 00:03:34,520 --> 00:03:43,120 Speaker 1: limited buffet options among the stars. Today's episode was written 63 00:03:43,120 --> 00:03:46,040 Speaker 1: by Nathan Chandler and produced by Tristan McNeil. For more 64 00:03:46,080 --> 00:03:48,400 Speaker 1: on this and lots of other tasty topics, visit our 65 00:03:48,400 --> 00:04:02,040 Speaker 1: home planet, how stuff Works dot com.