If you are human, you have to, and astronauts are no exception.
When Neil Armstrong first photographed the moon's surface, the tossed garbage bag presumably contained his own excrement. Apollo astronauts left a total of 96 bags of garbage containing urine and feces at six landing sites. The excrement remains in its place today.
All of the iconic photos of the astronauts on the Apollo 11 mission were taken by Armstrong. The astronaut standing next to the American flag in the photo above is Buzz Aldrin; The white object on the left edge of the image is the garbage bag.
Since the Apollo "poo bags" were dropped on the moon more than 50 years ago, they have been the subject of public attention and speculation. Human feces are full of microbes, which means that every Apollo landing leaves life on Earth on the surface of the moon, and it is impossible to estimate how long microbes will survive – if we can know how long they will survive, we will hopefully shed light on the mystery of the origin of life on Earth and speculate about the existence of extraterrestrial life. On the other hand, these poop bags also highlight the tricky nature of managing and disposing of extraterrestrial biological waste.
Right now, governments and business players are pushing hard for a human return to the moon; And subsequent moon stays can last for weeks, months, or even indefinitely. As a result, we have to pay attention to and solve all aspects of the problems related to "moon".
Melissa de Zwart, a professor at the University of Adelaide in Australia, specializes in legal and regulatory issues related to extraterrestrial environments. "If humans are going to live on the moon permanently, you don't want to litter feces everywhere," she said. It's unsightly, and it's dangerous. The question is, what environmental standards do we use? There are no hard and fast rules yet. ”
Since the first human body was sent into space, the "dirty work" of space waste management and disposal has puzzled astronauts and mission planners. In a 1971 paper on this topic, the author said: "When we discuss the biological function of human beings, it is more likely to elicit laughter than interest." But no matter how embarrassing the topic may be, it is important for human spaceflight, and "astronauts quickly learned the importance of gravity in the mechanism of defecation."
The silky bowel movements of animals on Earth depend on gravity. In microgravity or lunar gravity, excrement is not easily separated from the body, and its subsequent behavior is unpredictable. The phrase "fecal popcorning" was coined to refer to the process by which space feces "pop" out of a space toilet box.
David Munns, a professor of history of science and technology at the City University of New York, explains: "In space, there is basically no gravity to help humans pull feces out of the anus. So becomes a matter of surface tension of viscous liquids. It is worth mentioning that Munes co-authored a book on space waste management in 2021 with Kärin Nickelsen, a professor at the University of Munich in Germany.
When the space age began, American astronauts had to go to the toilet by sticking a bag to the buttock-eye area. But this convenient practice was notorious for being "stinky" and eventually caused feces to float out of the Apollo 10 command module. Astronaut Frank Borman, who has a lot of endurance, once decided to stick to Gemini 7 for more than a week without a bowel movement to avoid his notorious "stink".
Today, toilets (or toilets) on the ISS are equipped with hoses and suction cups that use suction to remove urine and feces, providing greater comfort and convenience for astronauts. But scientists have yet to develop a circulatory system that can dispose of all the biological waste produced by humans – urine, feces, vomit and menstrual blood. This is a major technological gap for future human space exploration.
NASA is currently leading the Artemis program, which aims to return humans to the lunar surface; The continent's space program also includes a goal to send astronauts to the moon in the next decade. Many leaders in the commercial space sector, such as Richard Branson, the founder of the British Virgin Group, predict that one day ordinary people will visit the moon as tourists. To achieve these ambitious visions, we must first ditch the poop bags, space diapers, and fecal popcorn of the past and create the lunar toilet of the future.
To this end, NASA launched the Lunar Loo Challenge in 2020, calling on the international community to submit "novel design ideas for compact toilets that can be used in microgravity and lunar gravity." The winning concept, called "Superlunar Supercritical Storage 1" (THRONE), was inspired in part by the familiar plastic bag for baby diaper storage that many parents are familiar with, which seals the waste immediately after disposal with plastic to reduce odor.
So, where should the stored space excrement go? And how to deal with it? There is still no clear idea. Michael Rapley, deputy manager of the crew module of NASA's manned lunar landing system at NASA's Johnson Space Center, said: "The waste management design is still under review, but NASA's goal is to minimize any potential impact on the lunar surface. ”
Lapley noted that manned spaceflight cannot be achieved without a successful solution to the problem of human waste management. "One of the key challenges faced by NASA and its Artemis partners in next-generation lunar missions is waste management system development. The system would not only be able to successfully collect waste in weightless environments, such as the International Space Station in low-Earth orbit, but also in lunar gravity (1/6 of the Earth). ”
Whatever the final design of the Artemis manned spacecraft, it will be the result of more than five decades of space innovation. For the astronauts of the Apollo spacecraft in the past, their first concern was to ensure that the spacecraft returned to Earth, and that anything that was not necessary, including waste from the toilet, was discarded. The potential risk of fecal microbial contamination of the lunar environment pales nothing in the face of the pragmatic need to send people home safely.
Hugo Lopez, a researcher at France's National Center for Scientific Research, wrote in a 2020 study: "In the long run, the contents of these bags could become a huge concern for the lunar environment and for future human scientific activities on the moon." In addition, the introduction of terrestrial material into extraterrestrial bodies such as the Moon could permanently endanger the possible presence of native life on the celestial bodies. ”
In other words, there is a very small chance that microbes in human feces could interfere with life on the moon. (Although, given the Moon's harsh environment, it is highly unlikely that lunar life exists.) Mark Lupisella, an exploration integration manager at NASA's Goddard Space Flight Center, proposed a robotic mission to collect samples from garbage bags left behind at an Apollo mission landing site. Analysis of these samples is expected to answer a range of novel scientific questions that are critical for future exploration:
Can fecal microbes survive on the moon and for how long? Will exposure to such harsh conditions cause any mutations or adaptations? Can they disperse into the wider lunar environment?
Lupitera proposed experiments such as biomolecular sequencing of Apollo astronaut feces. Such work may reveal whether microbes have undergone alterations in genetic mutation rates after being abandoned on the moon (which may provide an adaptive advantage). Lupisela also wanted to know if the microbial spores in the poop bag could be revived under the right conditions.
We know that life can be very tenacious and can survive in all kinds of harsh environments. If the human microbiome can survive on the moon, it will be more indicative of the tenacity of life and a reminder that there is absolutely reason to believe in the Milky Way, the solar system, and even beyond. ”
Dezwatt said that if we can innovate the big problem of space waste, life on Earth will also benefit a lot from it.
For example, billions of people on the planet currently lack access to safe sanitation services, which requires more innovative toilets and sewage systems. On the other hand, the increasing number of livestock worldwide, which produces billions of tons of manure every year, puts tremendous pressure on waste management projects. Wastewater often pollutes the environment and poses a health threat to humans, including respiratory diseases or waste-related pathogens. Wastewater systems currently contribute to greenhouse gas emissions; And the effects of climate change, including extreme weather events such as floods or hurricanes, are putting more pressure on waste infrastructure.
Sources:
Pooping on the Moon Is a Messy Business
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