Packing for Mars: The Curious Science of Life in the Void

by Mary Roach

  Starving your astronauts for the duration of the mission would resolve another early NASA concern: waste management. Not only was the act of using a fecal bag powerfully objectionable, but the end product stank and took up precious cabin space. “What the astronauts wanted to do is to just be able to take a pill and not eat,” says Bourland. “They talked about it all the time.” The food scientists tried but failed to make it happen. The astronauts’ fall-back solution was to skip meals, a deprivation made bearable by the knowledge of what awaited them inside the meal pouches.

  Jim Lovell and Frank Borman would be stuck in the Gemini VII capsule for fourteen days. Fasting was no longer a viable waste management strategy. (Almost though: “Frank went, I think, nine days without having to go to the bathroom,” says Lovell in his NASA oral history transcript. At which point Borman announced, “Jim, this is it.” And Lovell replied, “Frank, you only have five more days left to go here!”) The new imperative at NASA was to develop food that was not only lightweight and compact, but also “low-residue.” “On the short missions of Mercury and Gemini,” wrote Borman in his memoir, “a bowel movement was rare.”

  Cue the simulated astronauts again. Technical Report AMRL 66-147, “Effects of Experimental Diets and Simulated Space Conditions on the Nature of Human Waste,” details the fourteen very trying days of four men who served as digestive stand-ins for Lovell and Borman in the AMRL simulator. The first diet tested was the infamous all-cube diet: little sandwich cubes, “meat bites,” and miniature desserts. It was like dolls were running the kitchen.

  The cubes were a digestive fiasco. The coating had been modified, with palm kernel oil used in place of lard. The palm oil waltzed through the gut largely undigested, giving the young airmen steatorrhea, and you and me a new vocabulary word. (Steatorrhea is fatty stool, as opposed to diarrhea, which is watery stool.) The steatorrhea created, to quote the San Antonio Express,* “gastrointestinal effects which were incompatible with efficient performance in an orbiting vehicle.” The reporter was being coy, but the technical paper spelled it out. Oily stools are foul-smelling and messy. Official descriptor number 3—“mushy but not liquid”—was the one most commonly applied by the subjects (whose day-to-day miseries were amplified by the task of inspecting and scoring their own waste). The report didn’t mention anal leakage, but I will. If you have oil in your stools—be it from Olestra or from space food cube coatings—some of it may ooze out. When you have one pair of underpants for a two-week spaceflight, anal leakage is not your pal.

  Also tested was one of the liquid diets: forty-two days of milk-shakes. The thinking was that a liquid diet would cut down on both the volume of solid waste generated by the men, as well as their “defecation discharge frequency.” If you drink it, the thinking probably went, you’ll pee it. Not so. Because of all the dissolved fibers in the drinks, “daily mass” (forgive me, Father) sometimes increased significantly, in one case more than doubling.

  IRONICALLY, IF YOU wanted to minimize an astronaut’s “residue,” you could have fed him exactly what he wanted: a steak. Animal protein and fat have the highest digestibility of any foods on Earth. The better the cut, the more thoroughly the meat is digested and absorbed—to the point where there’s almost nothing to egest (opposite of ingest). “For high-quality beef, pork, chicken, or fish, digestibility is about ninety percent,” says George Fahey, professor of animal and nutritional sciences at the University of Illinois at Urbana-Champaign. Fats are around 94 percent digestible. A 10-ounce sirloin steak generates but a single ounce of, as they say in George Fahey’s lab, egesta.* Best of all: the egg. “Few foods,” writes Franz J. Ingelfinger, a panelist at the 1964 Conference on Nutrition in Space and Related Waste Problems, “are digested and assimilated as completely as a hard-boiled egg.” That’s one reason NASA’s traditional launch day breakfast is steak and eggs.† An astronaut may be lying on his back, fully suited, for eight hours or more. You do not want to be eating Fiber One the morning before liftoff. (The Soviet space agency did not traditionally give cosmonauts steak and eggs before launch; it gave them a one-liter enema.)

  Fahey, my residue expert, consults for the pet food industry. These are the animal sciences people that NASA should have been working with, not the Air Force vets. The top two concerns of the pet food manufacturer? Palatability and “fecal characteristics”: a clean bowl and a clean living room carpet. First and foremost, dog owners want to feed their pet something it appears to like. I like to think that is NASA’s goal as well. “And the number-two concern,” said Fahey, setting up a joke he had not intended to make, “is stool consistency. We like to have a fecal material that is hard enough to be picked up and disposed of easily. Not some big mass of runny stuff.” Ditto the Gemini and Apollo astronauts.

  Pet-food makers also share the early space food scientists’ goal of low “defecation discharge frequency.” A dog in a high-rise apartment has but two discharge opportunities: once in the morning before its owner leaves for work, and again in the evening. “They have to be able to hold it eight hours,” says Fahey. Just like the astronaut on the launch pad. Or the astronaut hoping to put as much time as possible between encounters with the fecal bag.

  The other way to lower discharge frequency might be to choose a mellow breed of astronaut. Hyperactive dogs have fast metabolisms; food passes through quickly, so it doesn’t have a chance to be completely digested. Hunting dogs, high-strung by nature, tend to have runny stools. And because they’re programmed to bound off after prey at any given moment, they wolf their food (no doubt the origin of the verb). This compounds the problem. The less you chew your food, the more of it passes through undigested.

  What would Fahey have fed the early astronauts? As a starch, he recommended rice, because it’s the lowest-residue of all the carbohydrates. (This is why Purina makes Lamb & Rice, not Lamb & Fingerling Potatoes.) Fresh fruits and vegetables he’d skip, as they create a high-volume, high-frequency stool situation. On the other hand, if you feed someone highly processed foods with no residue, no fiber at all, they’ll be constipated. Which, depending on the length of the flight, could be ideal: “Under current conditions,” wrote Franz Ingelfinger, “with the emphasis on short-term flights, I am sure that the most practical solution to the waste-disposal problem has been a constipated astronaut.”

  TWELVE YEARS AFTER the corned-beef-sandwich incident, astronaut John Young yet again embarrassed his employer in the national news media. Young, along with Apollo 16 crewmate Charlie Duke, was sitting in the Lunar Module Orion after a day out and about collecting rocks. During a radio debriefing with Mission Control, out of the blue, Young declares, “I got the farts again. I got ’em again, Charlie. I don’t know what the hell gives them to me…. I think it’s acid in the stomach.” Following Apollo 15, in which low potassium levels were blamed for the heart arrhythmias of the crew, NASA had put potassium-laced orange, grapefruit, and other citrus drinks on the menu.

  Young kept going. It’s all there in the mission transcript. “I mean, I haven’t eaten this much citrus fruit in 20 years. And I’ll tell you one thing, in another 12 fucking days, I ain’t never eating any more. And if they offer to serve me potassium with my breakfast, I’m going to throw up. I like an occasional orange, I really do. But I’ll be damned if I’m going to be buried in oranges.” Moments later, Mission Control comes on the line and provides Young with yet more fodder for indigestion.

  CAP COM [capsule communicator]: Orion, Houston.

  YOUNG: Yes, sir.

  CAP COM: Okay, you [have] a hot mike.

  YOUNG: Oh. How long have we had that?

  CAP COM: It’s been on through the debriefing.

  This time, it wasn’t Congress that got riled. The day after Young’s comments hit the press, the governor of Florida issued a statement in defense of his state’s key crop, which Charlie Duke paraphrases in his memoir: “It is not our orange juice that is causing the trouble. It’s an artificial substitute that doesn’t come from Florida.”


  In fact, it was the potassium, not the orange juice. The “coefficient of flatulence” for orange juice—to use the terminology of USDA flatus researcher Edwin Murphy, another panelist at the 1964 Conference on Nutrition in Space and Related Waste Problems—is low.

  Murphy reported on research he had done using an “experimental bean meal” fed to volunteers who had been rigged, via a rectal catheter, to outgas into a measurement device. He was interested in individual differences—not just in the overall volume of flatus but in the differing percentages of constituent gases. Owing to differences in intestinal bacteria, half the population produces no methane. This makes them attractive as astronauts, not because methane stinks (it’s odorless), but because it’s highly flammable. (Methane is what utility companies sell, under the rubric “natural gas.”) *

  Murphy had a unique suggestion for the NASA astronaut selection committee: “The astronaut may be selected from that part of our population producing little or no methane or hydrogen”—hydrogen is also explosive—“and a very low level of hydrogen sulfide or other malodorous trace flatus constituents not yet identified…. Further, since some individual astronauts may vary in the degree of flatulent reaction to a given weight of food, individuals can be chosen who demonstrate a high resistance to intestinal upset and flatus formation.”

  In his work, Murphy had encountered one such ideal astronaut candidate. “Of special interest for further research was the subject who produced essentially no flatus on 100 grams dry weight of beans.” As opposed to the average gut, which will, during the peak flatulence period (five to six hours post–bean consumption) pass anywhere from one to almost three cups of flatus per hour. At the high end of the range, that’s about two Coke cans full of fart. In a small space where you can’t open the window.

  As an alternative to recruiting the constitutionally nonflatulent, NASA could create non-“producers” by sterilizing their digestive tract. Murphy had fed the notorious bean meal to a subject who was taking an antibacterial drug and found that the man expelled 50 percent less gas. The saner approach, and the one NASA actually took, was to simply avoid your high coefficient-of-flatus foods. Up through Apollo, beans, cabbage,* Brussels sprouts, and broccoli were blacklisted. “Beans were not used until Shuttle,” states Charles Bourland.

  There are those who welcomed their arrival, and not just because they’re tasty. The zero-gravity fart has been a popular orbital pursuit, particularly on all-male flights. One hears tell of astronauts using intestinal gas like rocket propellant to “launch themselves across the middeck,” as astronaut Roger Crouch put it. He had heard the claims and was dubious. “The mass and velocity of the expelled gas,” he told me in an email that has forevermore endeared him to me, “is very small compared to the mass of the human body.” Thus it was unlikely that it could accelerate a 180-pound astronaut. Crouch pointed out that an exhaled breath doesn’t propel an astronaut in any direction, and the lungs hold about six liters of air—versus the fart, which, as we learned from Dr. Murphy, holds at most three soda cans’ worth.

  Or the average person’s, anyway. “My genes have blessed me with an extraordinary ability to expel some of the byproducts of digestion,” wrote Crouch. “So given that, I thought that it should be tested. In what I thought was a real voluminous and rapidly expelled purge, I failed to move noticeably.” Crouch surmised that his experiment may have been compromised by the “action/reaction of the gas passing through the pants.” Disappointingly, both his flights were mixed-gender, so Crouch was disinclined to “strip down naked” and try it again. He was heading to Cape Canaveral and promised to ask around for some other astronauts’ input, but so far no one is, as they say, spilling the beans.

  ASTRONAUT FOOD IN recent decades has grown kinder and more normal. Meals no longer have to be compressed or dehydrated, as there’s plenty of storage room on the International Space Station. Entrées are sealed in plastic pouches, thermostabilized, and then reheated in a small unit that resembles a briefcase. With the 2010 publication of Charles Bourland’s incomparable Astronaut’s Cookbook, it is now possible to whip up eighty-five high-fidelity shuttle-era entrées and sides in your own kitchen, should your own kitchen happen to contain “National 150 filling starch aid from National Starch and Chemical Company” and “caramelized garlic base #99-404 from Eatem Foods.”

  For a Mars mission, however, things may get strange all over again.

  EATING YOUR PANTS

  Is Mars Worth It?

  I will tell you sincerely and without exaggeration that the best part of lunch today at the NASA Ames cafeteria is the urine. It is clear and sweet, though not in the way mountain streams are said to be clear and sweet. More in the way of Karo syrup. The urine has been desalinated by osmotic pressure. Basically it swapped molecules with a concentrated sugar solution. Urine is a salty substance (though less so than the NASA Ames chili), and if you were to drink it in an effort to rehydrate yourself, it would have the opposite effect. But once the salt is taken care of and the distasteful organic molecules have been trapped in an activated charcoal filter, urine is a restorative and surprisingly drinkable lunchtime beverage. I was about to use the word unobjectionable, but that’s not accurate. People object. They object a lot.

  “It makes me sick to have urine in the refrigerator,” said my husband Ed. I had finished running yesterday’s output through the charcoal and the osmosis bag, and had placed it, in a glass bottle, on the door of the fridge pending lunch down in Mountain View. I replied that everything objectionable had been filtered out, and that astronauts don’t mind drinking treated urine. Ed made a flaring motion with his nostrils and said that circumstances would have to be “postapocalyptic” for him to consider it.

  My lunch date at Ames is Sherwin Gormly, a waste-water engineer who helped design the rig to recycle urine on the International Space Station. He has been referred to in the press as “the urine king.” This doesn’t bother him. What bothered him was being known, briefly, as the guy who said that the moon might be a good place to store weapons-grade plutonium out of reach of megalomaniacal despots. It wasn’t a serious suggestion; just Gormly idly speculating. That’s what they do down at Ames. In case you didn’t pick this up from Norbert Kraft, the NASA of Ames is a different critter from the NASA of Johnson Space Center. “We’re a think tank here at Ames,” says Gormly. “We’re kinda the wingnuts.” Gormly is dressed in cargo pants and a lavender Henley shirt. There’s nothing especially radical about cargo pants and lavender shirts, but in four trips to Johnson Space Center, I never saw either. Gormly is fit and tan. You’d have to inspect him closely to guess his age correctly; some gray creeping into the blond crewcut, the eyebrows just starting to sprout crazies.

  We’re not scheduled to land on Mars until sometime in the 2030s, but it’s always at the back of the collective NASA mind. The things dreamt up for a lunar base these past five years were dreamt with an eye on Mars. Much of the most innovative stuff comes out of Ames. Not that it will all fly. “Nothing we do,” says Gormly, “becomes a space reality until it goes through some filters downstream.” You probably want to run anything Sherwin Gormly gives you through some filters.

  Landing a spacecraft on Mars is yesterday’s challenge. Space agencies have been blasting landers to Mars for three decades. (Remember, once a craft reaches space, there’s no air drag to slow it down; it keeps traveling through the vacuum of space without needing more rocket power, aside from small course corrections. Space ships basically coast to Mars. The fuel they’d need is for landing and for the return blast back.) Rockets powerful enough to accelerate an 800-pound lander to Mars are a whole other animal from a rocket that can do so while carrying five or six humans and two-plus years’ worth of supplies.

  Back in the sixties, when aerospace scientists assumed that the follow-up to a moon landing would be a manned Mars mission, some fantastical Ames-style creativity was afoot. An obvious alternative to launching 8,000 pounds of food is to grow it—or some of it—on bo
ard in greenhouses. But in the early sixties, meat ruled the dinner plate. The space nutritionists, for a brief and wondrous moment, turned their minds to the possibility of zero-gravity ranching. “What type of animal should be taken along to Mars or Venus?” asked animal husbandry professor Max Kleiber at the 1964 Conference on Nutrition in Space and Related Waste Problems. Kleiber held an accommodating view of animal husbandry; he included rats and mice in his calculations along with cattle and sheep. He left the unpretty logistics of zero-gravity slaughter and manure management to others, for Kleiber was a metabolism man. He simply wished to know: Which beast provides the greatest number of calories for the lowest launch weight and feed consumption? To serve beef to two or three Mars astronauts, “a steer of 500-kilogram body weight has to be hauled into space.” Whereas the same number of calories could be derived from just 42 kilograms of mice (about 1,700 of them). “The astronauts,” stated the paper’s conclusion, “should eat mouse stew instead of beef steaks.”

  Present at the same conference was D. L. Worf, of the Martin Marietta Company (before Lockheed got there). Worf was big on thinking outside the box, and then eating it. “Food may be processed by many of the same techniques that are used to fabricate structures and shapes from plastic.” Worf did not limit this thinking to food containers but included spacecraft structures normally jettisoned or left behind when preparing to return home. In other words, instead of abandoning the Lunar Module on the moon, the Apollo 11 crew could have broken off pieces to take along and eat on the way home. Thereby needing to carry less food in the first place. Worf envisioned a return-trip menu that included Fuel Tank, Rocket Motor, and Instrument Casing. Leave room for dessert! “Transparent sugar castings as a substitute for windows” also made Worf’s idea list.