Scientists Are Devising Clever Solutions to Feed Astronauts on Mars Space Flights
Astronauts at the International Space Station today depend on pre-packaged, freeze-dried food, plus some fresh produce thanks to regular resupply missions. This supply chain, however, will not be available on trips further out, such as the moon or Mars. So what are astronauts on long missions going to eat?
Going by the options available now, says Christel Paille, an engineer at the European Space Agency, a lunar expedition is likely to have only dehydrated foods. “So no more fresh product, and a limited amount of already hydrated product in cans.”
For the Mars mission, the situation is a bit more complex, she says. Prepackaged food could still constitute most of their food, “but combined with [on site] production of certain food products…to get them fresh.” A Mars mission isn’t right around the corner, but scientists are currently working on solutions for how to feed those astronauts. A number of boundary-pushing efforts are now underway.
The logistics of growing plants in space, of course, are very different from Earth. There is no gravity, sunlight, or atmosphere. High levels of ionizing radiation stunt plant growth. Plus, plants take up a lot of space, something that is, ironically, at a premium up there. These and special nutritional requirements of spacefarers have given scientists some specific and challenging problems.
To study fresh food production systems, NASA runs the Vegetable Production System (Veggie) on the ISS. Deployed in 2014, Veggie has been growing salad-type plants on “plant pillows” filled with growth media, including a special clay and controlled-release fertilizer, and a passive wicking watering system. They have had some success growing leafy greens and even flowers.
"Ideally, we would like a system which has zero waste and, therefore, needs zero input, zero additional resources."
A larger farming facility run by NASA on the ISS is the Advanced Plant Habitat to study how plants grow in space. This fully-automated, closed-loop system has an environmentally controlled growth chamber and is equipped with sensors that relay real-time information about temperature, oxygen content, and moisture levels back to the ground team at Kennedy Space Center in Florida. In December 2020, the ISS crew feasted on radishes grown in the APH.
“But salad doesn’t give you any calories,” says Erik Seedhouse, a researcher at the Applied Aviation Sciences Department at Embry-Riddle Aeronautical University in Florida. “It gives you some minerals, but it doesn’t give you a lot of carbohydrates.” Seedhouse also noted in his 2020 book Life Support Systems for Humans in Space: “Integrating the growing of plants into a life support system is a fiendishly difficult enterprise.” As a case point, he referred to the ESA’s Micro-Ecological Life Support System Alternative (MELiSSA) program that has been running since 1989 to integrate growing of plants in a closed life support system such as a spacecraft.
Paille, one of the scientists running MELiSSA, says that the system aims to recycle the metabolic waste produced by crew members back into the metabolic resources required by them: “The aim is…to come [up with] a closed, sustainable system which does not [need] any logistics resupply.” MELiSSA uses microorganisms to process human excretions in order to harvest carbon dioxide and nitrate to grow plants. “Ideally, we would like a system which has zero waste and, therefore, needs zero input, zero additional resources,” Paille adds.
Microorganisms play a big role as “fuel” in food production in extreme places, including in space. Last year, researchers discovered Methylobacterium strains on the ISS, including some never-seen-before species. Kasthuri Venkateswaran of NASA’s Jet Propulsion Laboratory, one of the researchers involved in the study, says, “[The] isolation of novel microbes that help to promote the plant growth under stressful conditions is very essential… Certain bacteria can decompose complex matter into a simple nutrient [that] the plants can absorb.” These microbes, which have already adapted to space conditions—such as the absence of gravity and increased radiation—boost various plant growth processes and help withstand the harsh physical environment.
MELiSSA, says Paille, has demonstrated that it is possible to grow plants in space. “This is important information because…we didn’t know whether the space environment was affecting the biological cycle of the plant…[and of] cyanobacteria.” With the scientific and engineering aspects of a closed, self-sustaining life support system becoming clearer, she says, the next stage is to find out if it works in space. They plan to run tests recycling human urine into useful components, including those that promote plant growth.
The MELiSSA pilot plant uses rats currently, and needs to be translated for human subjects for further studies. “Demonstrating the process and well-being of a rat in terms of providing water, sufficient oxygen, and recycling sufficient carbon dioxide, in a non-stressful manner, is one thing,” Paille says, “but then, having a human in the loop [means] you also need to integrate user interfaces from the operational point of view.”
Growing food in space comes with an additional caveat that underscores its high stakes. Barbara Demmig-Adams from the Department of Ecology and Evolutionary Biology at the University of Colorado Boulder explains, “There are conditions that actually will hurt your health more than just living here on earth. And so the need for nutritious food and micronutrients is even greater for an astronaut than for [you and] me.”
Demmig-Adams, who has worked on increasing the nutritional quality of plants for long-duration spaceflight missions, also adds that there is no need to reinvent the wheel. Her work has focused on duckweed, a rather unappealingly named aquatic plant. “It is 100 percent edible, grows very fast, it’s very small, and like some other floating aquatic plants, also produces a lot of protein,” she says. “And here on Earth, studies have shown that the amount of protein you get from the same area of these floating aquatic plants is 20 times higher compared to soybeans.”
Aquatic plants also tend to grow well in microgravity: “Plants that float on water, they don’t respond to gravity, they just hug the water film… They don’t need to know what’s up and what’s down.” On top of that, she adds, “They also produce higher concentrations of really important micronutrients, antioxidants that humans need, especially under space radiation.” In fact, duckweed, when subjected to high amounts of radiation, makes nutrients called carotenoids that are crucial for fighting radiation damage. “We’ve looked at dozens and dozens of plants, and the duckweed makes more of this radiation fighter…than anything I’ve seen before.”
Despite all the scientific advances and promising leads, no one really knows what the conditions so far out in space will be and what new challenges they will bring. As Paille says, “There are known unknowns and unknown unknowns.”
One definite “known” for astronauts is that growing their food is the ideal scenario for space travel in the long term since “[taking] all your food along with you, for best part of two years, that’s a lot of space and a lot of weight,” as Seedhouse says. That said, once they land on Mars, they’d have to think about what to eat all over again. “Then you probably want to start building a greenhouse and growing food there [as well],” he adds.
And that is a whole different challenge altogether.
The news last November that a rogue Chinese scientist had genetically altered the embryos of a pair of Chinese twins shocked the world. But although this use of advanced technology to change the human gene pool was premature, it was a harbinger of how genetic science will alter our healthcare, the way we make babies, the nature of the babies we make, and, ultimately, our sense of who and what we are as a species.
The healthcare applications of the genetics revolution are merely stations along the way to the ultimate destination.
But while the genetics revolution has already begun, we aren't prepared to handle these Promethean technologies responsibly.
By identifying the structure of DNA in the 1950s, Watson, Crick, Wilkins, and Franklin showed that the book of life was written in the DNA double helix. When the human genome project was completed in 2003, we saw how this book of human life could be transcribed. Painstaking research paired with advanced computational algorithms then showed what increasing numbers of genes do and how the genetic book of life can be read.
Now, with the advent of precision gene editing tools like CRISPR, we are seeing that the book of life -- and all biology -- can be re-written. Biology is being recognized as another form of readable, writable, and hackable information technology with we humans as the coders.
The impact of this transformation is being first experienced in our healthcare. Gene therapies including those extracting, re-engineering, then reintroducing a person's own cells enhanced into cancer-fighting supercells are already performing miracles in clinical trials. Thousands of applications have already been submitted to regulators across the globe for trials using gene therapies to address a host of other diseases.
Recently, the first gene editing of cells inside a person's body was deployed to treat the genetically relatively simple metabolic disorder Hunter syndrome, with many more applications to come. These new approaches are only the very first steps in our shift from the current system of generalized medicine based on population averages to precision medicine based on each patient's individual biology to predictive medicine based on AI-generated estimations of a person's future health state.
Jamie Metzl's groundbreaking new book, Hacking Darwin: Genetic Engineering and the Future of Humanity, explores how the genetic revolution is transforming our healthcare, the way we make babies, and the nature of and babies we make, what this means for each of us, and what we must all do now to prepare for what's coming.
This shift in our healthcare will ensure that millions and then billions of people will have their genomes sequenced as the foundation of their treatment. Big data analytics will then be used to compare at scale people's genotypes (what their genes say) to their phenotypes (how those genes are expressed over the course of their lives).
These massive datasets of genetic and life information will then make it possible to go far beyond the simple genetic analysis of today and to understand far more complex human diseases and traits influenced by hundreds or thousands of genes. Our understanding of this complex genetic system within the vaster ecosystem of our bodies and the environment around us will transform healthcare for the better and help us cure terrible diseases that have plagued our ancestors for millennia.
But as revolutionary as this challenge will be for medicine, the healthcare applications of the genetics revolution are merely stations along the way to the ultimate destination – a deep and fundamental transformation of our evolutionary trajectory as a species.
A first inkling of where we are heading can be seen in the direct-to-consumer genetic testing industry. Many people around the world have now sent their cheek swabs to companies like 23andMe for analysis. The information that comes back can tell people a lot about relatively simple genetic traits like carrier status for single gene mutation diseases, eye color, or whether they hate the taste of cilantro, but the information about complex traits like athletic predisposition, intelligence, or personality style today being shared by some of these companies is wildly misleading.
This will not always be the case. As the genetic and health data pools grow, analysis of large numbers of sequenced genomes will make it possible to apply big data analytics to predict some very complex genetic disease risks and the genetic components of traits like height, IQ, temperament, and personality style with increasing accuracy. This process, called "polygenic scoring," is already being offered in beta stage by a few companies and will become an ever bigger part of our lives going forward.
The most profound application of all this will be in our baby-making. Before making a decision about which of the fertilized eggs to implant, women undergoing in vitro fertilization can today elect to have a small number of cells extracted from their pre-implanted embryos and sequenced. With current technology, this can be used to screen for single-gene mutation diseases and other relatively simple disorders. Polygenic scoring, however, will soon make it possible to screen these early stage pre-implanted embryos to assess their risk of complex genetic diseases and even to make predictions about the heritable parts of complex human traits. The most intimate elements of being human will start feeling like high-pressure choices needing to be made by parents.
The limit of our imagination will become the most significant barrier to our recasting biology.
Adult stem cell technologies will then likely make it possible to generate hundreds or thousands of a woman's own eggs from her blood sample or skin graft. This would blow open the doors of reproductive possibility and allow parents to choose embryos with exceptional potential capabilities from a much larger set of options.
The complexity of human biology will place some limits to the extent of possible gene edits that might be made to these embryos, but all of biology, including our own, is extremely flexible. How else could all the diversity of life have emerged from a single cell nearly four billion years ago? The limit of our imagination will become the most significant barrier to our recasting biology.
But while we humans are gaining the powers of the gods, we aren't at all ready to use them.
The same tools that will help cure our worst afflictions, save our children, help us live longer, healthier, more robust lives will also open the door to potential abuses. Prospective parents with the best of intentions or governments with lax regulatory structures or aggressive ideas of how population-wide genetic engineering might be used to enhance national competitiveness or achieve some other goal could propel us into a genetic arms race that could undermine our essential diversity, dangerously divide societies, lead to dangerous, destabilizing, and potentially even deadly conflicts between us, and threaten our very humanity.
But while the advance of genetic technologies is inevitable, how it plays out is anything but. If we don't want the genetic revolution to undermine our species or lead to grave conflicts between genetic haves and have nots or between societies opting in and those opting out, now is the time when we need to make smart decisions based on our individual and collective best values. Although the technology driving the genetic revolution is new, the value systems we will need to optimize the benefits and minimize the harms of this massive transformation are ones we have been developing for thousands of years.
And while some very smart and well-intentioned scientists have been meeting to explore what comes next, it won't be enough for a few of even our wisest prophets to make decisions about the future of our species that will impact everyone. We'll also need smart regulations on both the national and international levels.
Every country will need to have its own regulatory guidelines for human genetic engineering based on both international best practices and the country's unique traditions and values. Because we are all one species, however, we will also ultimately need to develop guidelines that can apply to all of us.
As a first step toward making this possible, we must urgently launch a global, species-wide education effort and inclusive dialogue on the future of human genetic engineering that can eventually inform global norms that will need to underpin international regulations. This process will not be easy, but the alternative of an unregulated genetic arms race would be far worse.
The overlapping genomics and AI revolutions may seem like distant science fiction but are closer than you think. Far sooner than most people recognize, the inherent benefits of these technologies and competition between us will spark rapid adoption. Before that spark ignites, we have a brief moment to come together as a species like we never have before to articulate and translate into action the future we jointly envision. The north star of our best shared values can help us navigate the almost unimaginable opportunities and very real challenges that lie ahead.
Here's something to chew on. Can a gulp of water help save the planet? If you're drinking *and* eating your water at the same time, the answer may be yes.
The tasteless packaging is made from brown seaweed that biodegrades naturally in four to six weeks.
The Lowdown
A start-up company called Skipping Rocks Lab has created a "water bubble" encased in an edible sachet that you can pop in your mouth whole. Or if you're not into swallowing it, you can tear off the edge, drink up, and toss the rest in a composter. The tasteless packaging is made from brown seaweed that biodegrades naturally in four to six weeks, whereas plastic water bottles can linger for hundreds of years.
The founders of the London-based company are determined to "make plastic packaging disappear." They had two foodie inspirations: molecular gastronomists and fruit. They tried to emulate the way chefs used edible membranes to encase bubbles of liquid to make things like fake caviar and fake egg yolks; and they also considered the peel of an orange or banana, which protects the tasty insides but can be composted.
The sachets can also contain other liquids that come in single-serve plastic containers -- think packets of condiments with takeout meals, specialty cocktails at parties, and especially single servings of water for sporting events. The London Marathon last month gave out the water bubble pods at a station along the route, using them to replace 200,000 plastic bottles that would have likely ended up first in the street, and ultimately in the ocean.
Next Up
The engineers and chemists at Skipping Rocks intend to lease their machines to others who can then manufacture their own sachets on-site to fill with whatever they desire. The new material, which is dubbed "Notpla" (not plastic), also has other applications beyond holding liquids. It can be used to replace the plastic lining in cardboard takeout boxes, for example. And the startup is working on additional materials to replace other types of ubiquitous plastic packaging, like the netting that encases garlic and onions, and the sachets that hold nails and screws.
Edible water bubbles may be the future of drinks at sporting events and festivals.
Open Questions
One hurdle is that the pods are not very hardy, so while they work fine to hand out along a marathon route, they wouldn't really be viable for a hiker to throw in her backpack. Another issue concerns the retail market: to be stable on a shelf, they'd have to be protected from all that handling, which brings us back to the problem the engineers tried to solve in the first place -- disposable packaging.
So while Skipping Rocks may not achieve their ultimate goal of ridding the world of plastic waste, a little progress can still go a long way. If edible water bubbles are the future of drinks at sporting events and festivals, the environment will certainly benefit from their presence -- and absence.