To Boldly Go: The Science Behind Pooping in Space

iStock
iStock

What Mike Mullane remembers most clearly about having his first bowel movement in space is the blast of cold air greeting his exposed rectum. Over the course of three week-long NASA shuttle missions in the 1980s—two for Discovery, one for Atlantis—Mullane was forced to answer nature's call six or seven times in zero gravity. Each time, he would have to strip naked, close a flimsy curtain around a titanium commode, position his buttocks to form a perfect seal around a 4-inch opening, and then follow a checklist posted nearby to make sure no fecal particles escaped into the deck—all while his sphincter insisted on clamping shut to escape the freezing temperatures.

"It was a complex operation," Mullane tells Mental Floss. "On Earth, I'm fast. My wife is amazed I can be in and out of the bathroom in one minute for a number two. On the shuttle, it would take 30."

While the industrial toilet was a far cry from five-star hotel room seat warmers and bidets, it also improved by magnitudes the ordeal of emptying one's intestines in zero gravity. Prior to 1972, the men of the Gemini and Apollo missions braved poop bags that they would stick to their rear ends, then manually knead the contents with an antibacterial solution so the gases wouldn't detonate the collection; more than one crew has been terrorized by rogue turds hovering in the air.

Coming up with a practical way of replicating the earthbound poop experience took many years, many engineers, and a whole lot of ingenuity. While few explorers like to discuss it, taking a space dump is its own kind of heroism.

Consider one early—and discarded—solution for waste collection in space, which someone dubbed the "sh*t mitt." Donald Rethke likens it to "those long rubber gloves veterinarians use for insemination." The idea, he tells Mental Floss, was that the astronaut could poop in their own hand and then turn the glove inside-out, creating instant containment of the feces.

Now 80, Rethke is a retired engineer from Hamilton-Standard, a NASA subcontractor working through Northrop Grumman that spent decades refining or pioneering life-support systems for space explorers. Rethke, who embraces his industry nickname of "Doctor Flush," says that handling poop simply wasn't much of a concern due to the brief trips taken by pioneering astronauts: They could just go before they left. But as missions grew longer, it became necessary to address personal waste—urine and bowel movements—without dealing with the discomfort of diapers.

A NASA training commode
A training toilet with a camera positioned inside so astronauts can learn how to best angle their buttocks.
National Geographic, YouTube

For the 1965–66 Gemini excursions, which were planned to prove humans could survive for several days or weeks in space, astronauts were told to use a condom-like sheath that would direct urine into a bag. For feces, they were to use a pouch with a 1.5-inch opening and an adhesive strip around the edge to help prevent fecal matter from escaping. A fellow crew member would be told to stand by and watch to make sure no waste escaped into the capsule.

"It kind of looked like an upside-down top hat," Mullane says. Though they pre-dated his missions, they were on board his shuttles in case of equipment failure. "We never had to use them, thank God."

But the occupants of Gemini and Apollo did, and most found it unpleasant for reasons unrelated to crapping in a bag. When gravity is lacking, surface tension becomes a dominant force. So urine and feces that would separate from the body on Earth thanks to gravity tend to cling to the skin's surface in space.

"If you stick your finger into a glass of water and lift it up, water flows off," Mullane explains. "But in weightlessness, the attraction of the molecules of the fluid will pull it into a ball. If you leave fluid alone, it will form a perfect sphere. Touch it, and will stick to you."

The same goes for poop. The bags had tiny finger covers built in so users could flick and scrape errant flecks away from their cheeks. Then they'd mix in a chemical to kill the bacteria so the gases wouldn't expand in the sealed bag and create an explosive biohazard.

"Well, it's in a small, like a ketchup, a little plastic container like you find ketchup in in restaurants, in a cafeteria or something, it's like that," Apollo astronaut Russell Sweickhart told a reporter in 1977. "You tear the slit across the top, being careful not to squeeze it so the stuff comes out, and then you drop that into the fecal container, and then seal the fecal container. Then you squeeze it through the, you know, externally, you know, which forces it out of the container, and then you mix it by massaging the fecal bag. It's really fun when it's still warm."

If everything went well, it was merely disgusting. If it didn't, as the following transcript excerpt from the 1969 Apollo 10 mission demonstrates, it could be highly disruptive:

Tom Stafford: Give me a napkin quick. There's a turd floating through the air.

John Young: I didn't do it. It ain't one of mine.

Gene Cernan: I don't think it's one of mine.

Stafford: Mine was a little more sticky than that. Throw that away.

Young: God Almighty.

"When the Apollo astronauts came back," Rethke says, "they wanted sit-down toilets."

A look at the ISS bathroom
The "orbital outhouse" inside the International Space Station.
NASA

While modesty may not have been an achievable goal, astronauts needed some semblance of routine. (Some shuttles were equipped with kitchen tables, even though nothing in zero gravity could be perched on one.) But the comforts of a domestic commode had little application in space. No water could be used: It would run everywhere. And unlike gravity-assisted toilets, a shuttle john would have to address the surface tension issue that enticed poop to come out in curls instead of straight down, mashing itself against the skin.

The solution, according to Rethke, was gentle suction. "Or, as I like to call it, air entrainment," he says. In its simplest form, it's getting the poop Hoovered away from your bottom using air flow as a substitute for gravity.

Rethke says the idea was already on the table courtesy of General Electric (GE) when Hamilton-Standard began working on a zero gravity toilet, and that his job was one of refinement that lasted through the 1980s and 1990s. "The concept of separating solids from the body was already in the bag, no pun intended. It was just the best way. Most of my effort was how to do that economically."

NASA had previously toyed with a variety of designs, including one 1971 model that was mounted vertically on a wall to conserve space. Another took the feces and pulped it, a model not unlike evacuating into a blender. This, engineers realized, created the potential for fecal "dust," or powdered particles of poop, that could contaminate the cabin of spacecraft. By using air entrainment, hardly anything could escape the bowl—and if it did, it wouldn't be atomized to the point of being a biological hazard. Instead, a fan and vacuum system was used to encourage the waste to settle at the bottom of the waste tube.

Air entrainment made one frustrating demand of its users: proper anal positioning. With a 4-inch opening compared to a conventional toilet's 18 inches, astronauts had to align themselves up perfectly in order to avoid any escaping feces. To train astronauts heading for space, NASA set up a commode with a camera mounted inside. (You were not expected to make a deposit.) Users could gauge their perch based on freckles or other skin marks in relation to the seat. Properly docked, they could poop on target, but it took practice.

"It's hard to know where your a-hole is when the hole is that narrow," Mullane says.

Minor complaints aside, NASA's work was ready in time for the 1973 debut of Skylab, the first space station, and the 1981 launch of Columbia, the first shuttle to reach space. After realizing the pulverizing model wasn't going to work due to the fecal dust issue and other malfunctions that led to problems on 10 of the shuttle's first 11 voyages, a redesigned system less prone to clogging was introduced in the mid-1980s.

Urinating, according to Mullane, was never any big deal. Men and women use a form-fitting cup and gentle suction to empty their bladder. "Pretty simple," he says. "But solid waste, that was kind of like going in a camper toilet."

On the Atlantis and Discovery, the space commode had foot rests and thigh straps so astronauts could remain secure to the seat while doing their business. They'd typically opt to strip naked in the event any soiling occurred. To the right was a hand lever; pushed forward, it slid open the tube underneath their buttocks. "You never wanted to open that before sitting on it," Mullane says. Doing so could release the previous user's residual fecal matter into the air.

Once Mullane was strapped in, he would open the tube cover and feel the rush of cold air hit his rear. The air moved 360 degrees while a fan underneath—loud enough to mask sounds of elimination—pulled waste away from the body and into a container that would store the matter until the shuttle returned. Toilet paper would go in a separate bag. By the time Mullane got dressed, cleaned the toilet's edges, and exited, 30 minutes had passed.

Surprisingly, the intimate size of the shuttle didn't contribute to any fragrant evidence. "They did a really good job of filtration," Mullane says. "You never smelled anything."

Rethke improved on this in the early 1990s by compacting the discarded feces at the bottom, reducing the need for storage space. (To make sure it would stay sealed, Rethke once kept a feces-filled container in his office for a year.)

Small tweaks aside, the space toilet doesn't follow the update schedule of, say, an iPhone. What Rethke redesigned and what Mullane used is, by and large, what's still in use on the International Space Station (ISS) today. But instead of bringing waste back, it's discarded so it burns up in the atmosphere.

Future movements may prove more difficult to handle. With the advent of long-duration travel, possibly to Mars, on the horizon, space exploration will have to deal with the issue of waste management when there's virtually no chance of Earthbound assistance.

"When toilets fail [on Earth], it's a real pain," Mullane says. "Just imagine that on Mars. I have no idea how they're going to do that."

Someone might. In early 2017, the HeroX platform crowned a winner in its Space Poop Challenge, which crowdsourced ways to handle waste in space when an explorer is in a spacesuit and away from a fixed toilet for long periods. The winning idea—a suit hatch that can be used to insert inflatable bedpans and diapers—earned inventor Thatcher Cardon a $15,000 prize. If it works, it'll assist in an integral part of exploring beyond our atmospheric borders. In space, everyone needs to go.

Additional Sources: Riding Rockets: The Outrageous Tales of a Space Shuttle Astronaut

How the Hubble Space Telescope Helped the Fight Against Breast Cancer

NASA, Getty Images
NASA, Getty Images

The beauty of scientific research is that scientists never really know where a particular development might lead. Research on Gila monster venom has led to the invention of medication that helps manage type 2 diabetes, and enzymes discovered in the hot springs of Yellowstone National Park are now widely used for DNA replication, a technique used by forensic scientists to analyze crime scenes.

The same rule of thumb applies to NASA scientists, whose work has found dozens of applications outside of space exploration—especially in medicine.

Take the Hubble Space Telescope. Launched in 1990, the Hubble has graced us with stunning, intimate photographs of our solar system. But it wasn't always that way—when the telescope was launched, the first images beamed back to earth were awfully fuzzy. The image processing techniques NASA created to solve this problem not only sharpened Hubble's photos, but also had an unexpected benefit: Making mammograms more accurate.

As NASA reports, "When applied to mammograms, software techniques developed to increase the dynamic range and spatial resolution of Hubble's initially blurry images allowed doctors to spot smaller calcifications than they could before, leading to earlier detection and treatment."

That's because the Hubble Space Telescope contains a technology called Charge-Coupled Devices, or CCDs, which are basically electron-trapping gizmos capable of digitizing beams of light. Today, CCDs allow "doctors to analyze the tissue by stereotactic biopsy, which requires a needle rather than surgery," NASA says [PDF]. Back in 1994, NASA predicted that this advancement could reduce national health care costs by approximately $1 billion every year.

And that's just one of the tools NASA has developed that's now being used to fight breast cancer. When cancer researcher Dr. Susan Love was having trouble studying breast ducts—where breast cancer often originates—she turned to research coming out of NASA's Jet Propulsion Laboratory. As Rosalie Chan reports for the Daily Beast, the Jet Propulsion Lab has dedicated vast resources to avoiding the spread of earthly contaminants in space, and its research has included the development of a genomic sequencing technology that is "clean and able to analyze microscopic levels of biomass." As Dr. Love discovered, the same technology is a fantastic way to test for cancer-linked microorganisms in breast duct tissue.

A second technology developed at NASA's Jet Propulsion Laboratory—the Quantum Well Infrared Photodetector, or QWIP—enables humans to see invisible infrared light in a spectrum of colors, helping scientists discover caves on Mars and study volcanic emissions here on Earth. But it's also useful at the doctor's office: A QWIP medical sensor can detect tiny changes in the breast's blood flow—a sign of cancer—extremely early.

And as any doctor will tell you, that's huge: The earlier cancer is detected, the greater a person's chance of survival.

11 Things You Might Not Know About Neil Armstrong

NASA/Hulton Archive/Getty Images
NASA/Hulton Archive/Getty Images

No matter where private or government space travel may take us in the future, NASA astronaut Neil Armstrong (1930-2012) will forever have a place as the first human to ever set foot on solid ground outside of our atmosphere. Taking “one small step” onto the moon on July 20, 1969, he inspired generations of ambitious people to reach for the stars in their own lives. And ow, he's inspired a new biopic, First Man, which will see Ryan Gosling re-team with his La La Land director Damien Chazelle as it arrives in theaters this weekend.

1. HE KNEW HOW TO FLY BEFORE HE GOT A DRIVER’S LICENSE.

Neil Armstrong poses for a portrait 10 years before the 1969 Apollo mission
NASA/Hulton Archive/Getty Images

Born August 5, 1930 in Wapakoneta, Ohio, Armstrong became preoccupied with aviation early on. At around age 6, his father took him on a ride in a Ford Trimotor airplane, one of the most popular airplanes in the world. By age 15, he had accumulated enough flying lessons to command a cockpit, reportedly before he ever earned his driver’s license. During the Korean War, Armstrong flew 78 combat missions before moving on to the National Advisory Committee for Aeronautics (NACA), the precursor to NASA.

2. HIS FAMOUS QUOTE GETS MISINTERPRETED.

When Armstrong and Buzz Aldrin touched down on the moon, hundreds of millions of television viewers were riveted. Armstrong could be heard saying, “That’s one small step for man, one giant leap for mankind.” But that’s not exactly what he said. According to the astronaut, he was fairly sure he stated, “That’s one small step for a man, one giant leap for mankind.” The “a” may have broken up on transmission or it may have been obscured as a result of his speaking patterns. (According to First Man: The Life of Neil A. Armstrong, Armstrong said, “I’m not particularly articulate. Perhaps it was a suppressed sound that didn’t get picked up by the voice mike. As I have listened to it, it doesn’t sound like there was time for the word to be there. On the other hand, I think that reasonable people will realize that I didn’t intentionally make an inane statement, and certainly the ‘a’ was intended, because that’s the only way the statement makes any sense. So I would hope that history would grant me leeway for dropping the syllable and understand that it was certainly intended, even if it wasn’t said—although it actually might have been.”) Armstrong claimed the statement was spontaneous, but his brother and others have claimed he had written it down prior to the mission.

3. WE DON’T HAVE A REALLY GOOD PICTURE OF HIM ON THE MOON.

Buzz Aldrin is seen walking on the moon
NASA/Hulton Archive/Getty Images

One of the most celebrated human achievements of the 20th century came at a time when video and still cameras were readily available—yet there are precious few images of Armstrong actually walking on the surface of the moon. (One of the most iconic shots, above, is Aldrin; Armstrong only appears as a reflection in his helmet.) The reason, according to Armstrong, is that he really didn’t care and didn’t think to ask Aldrin to snap some photos. “I don't think Buzz had any reason to take my picture, and it never occurred to me that he should,” Armstrong told his biographer, James R. Hansen. “I have always said that Buzz was the far more photogenic of the crew."

4. A DOOR HINGE MAY HAVE MADE ALL THE DIFFERENCE.

Theories abound as to why it was Armstrong and not Buzz Aldrin who first set foot on the moon. (On the Gemini missions, the co-pilot did the spacewalks, while the commander stayed in the craft. For Apollo 11, Armstrong was the commander.) The answer may have been the simple logistics of getting out of their lunar module. The exit had a right hinge that opened inwardly, with the man sitting on the left (Armstrong) having the most unobstructed path to the outside. Aldrin would have essentially had to climb over Armstrong to get out first.

5. HE WAS MORE CONCERNED ABOUT LANDING ON THE MOON THAN HE WAS WALKING ON IT.

The lunar module that took NASA astronauts to the moon
NASA/Hulton Archive/Getty Images

The romantic notion of a human stepping foot on space soil captured imaginations, but for Armstrong, it was getting there in one piece that was the real accomplishment. The lunar module Armstrong controlled had to be brought down on the moon’s surface from 50,000 feet up, avoiding rocks, craters, and other obstacles as it jockeyed into a position for landing. Because there is no air resistance, nothing could slow their descent, and they used thrusters to guide the craft down. That meant there was only enough fuel to attempt it once. The “business” of getting down the ladder was, in Armstrong’s view, less significant.

6. HE WAS CARRYING A BAG WORTH $1.8 MILLION.

When Armstrong surveyed the surface of the moon, he collected a bag of dust for NASA scientists to examine. Apollo moon samples are illegal to buy or sell, but that apparently wasn't the case with the “lunar collection bag” Armstrong used to hold the samples. In 2015, the bag was purchased by Chicago resident Nancy Lee Carlson from a government auction site for $995. But its sale was, apparently, an accident: When Carlson sent the bag to NASA to confirm its authenticity, NASA said it was their property and refused to send it back—so Carlson took the agency to court. A judge ruled it belonged to Carlson, and in 2017, she sold the bag for a whopping $1.8 million at a Sotheby’s auction.

7. HE HAD TO SPEND THREE WEEKS IN QUARANTINE.

Richard Nixon greets the returning Apollo 11 astronauts
NASA/Hulton Archive/Getty Images

When Armstrong, Aldrin, and Michael Collins (who remained behind in the command module while the other two touched down on the moon) returned to Earth and were fetched by the USS Hornet, they got a king’s welcome. The only asterisk: They had to bask in their newfound fame from inside a sealed chamber. All three men were quarantined for three weeks in the event they had picked up any strange space virus. When President Richard Nixon visited, he greeted them through the chamber’s glass window.

8. HIS APOLLO SPACE SUIT WAS MADE BY PLAYTEX.

Yes, the undergarment people. In the early 1960s, NASA doled out contract work for their space suits to government suppliers, but it was Playtex (or more properly the International Latex Corporation) and their understanding of fabrics and seams that led to NASA awarding them responsibility for the Apollo mission suits. Their A7L suit was what Armstrong wore to insulate himself against the harsh void of space when he made his famous touchdown. The astronaut called it “reliable” and even “cuddly.”

9. HE BECAME A UNIVERSITY PROFESSOR.

Newil Armstrong sits behind a desk in 1970
AFP/Getty Images

Following his retirement from NASA in 1971, Armstrong was reticent to remain in the public eye. Demands for his time were everywhere, and he had little ambition to become a walking oral history of his singular achievement. Instead, he accepted a job as a professor of engineering at the University of Cincinnati and remained on the faculty for eight years.

10. HE ONCE SUED HALLMARK.

Hallmark was forced to defend itself when Armstrong took issue with the company using his name and likeness without permission for a 1994 Christmas ornament. The bulb depicted Armstrong and came with a sound chip that said phrases like, “The Eagle has landed.” The two parties came to an undisclosed but “substantial” settlement in 1995, which was, according to First Man, donated to Purdue University (minus legal fees).

11. HE ENDORSED CHRYSLERS.

Armstrong’s preference to lead a private life continued over the decades, but he did make one notable exception. For a 1979 Super Bowl commercial spot, Armstrong agreed to appear on camera endorsing Chrysler automobiles. Armstrong said he did it because he wanted the struggling U.S. car maker to improve their sales and continue contributing to the domestic economy. The ads never mentioned Armstrong was an astronaut.

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