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.
Waste smothering our oceans is worth billions – here’s what we can do with all that sh$t
There’s hardly a person out there who hasn’t heard of the Great Pacific Garbage Patch. That type of pollution is impossible to miss. It stares you in the face from pictures and videos of sea turtles with drinking straws up their noses and acres of plastic swirling in the sea.
It demands you to solve the problem—and it works. The campaign to raise awareness about plastic pollution in the oceans has resulted in new policies, including bans on microplastics in personal care products, technology to clean up the plastic, and even new plastic-like materials that are better for the environment.
But there’s a different type of pollution smothering the ocean as you read this. Unfortunately, this one is almost invisible, but no less damaging. In fact, it’s even more serious than plastic and most people have no idea it even exists. It is literally under our noses, destroying our oceans, lakes, and rivers – and yet we are missing it completely while contributing to it daily. In fact, we exacerbate it multiple times a day—every time we use the bathroom.
It is the way we do our sewage.
Most of us don’t think much about what happens after we flush the toilet. Most of us probably assume that the substances we flush go “somewhere” and are dealt with safely. But we typically don’t think about it beyond that.
Most of us also probably don’t think about what’s in the ocean or lakes we swim in. Since others are swimming, jumping in is just fine. But our waterways are far from clean. In fact, at times they are incredibly filthy. In the US, we are dumping 1.2 trillion of gallons of untreated sewage into the environment every year. Just New York City alone discharges 27 billion gallons into the Hudson River basin annually.
How does this happen? Part of it is the unfortunate side effect of our sewage system design that dates back to over a century ago when cities were smaller and fewer people were living so close together.
Back then, engineers designed the so-called “combine sewer overflow systems,” or CSOs, in which the storm water pipes are connected to the sanitary sewer pipes. In normal conditions, the sewage effluent from homes flows to the treatment plants where it gets cleaned and released into the waterways. But when it rains, the pipe system becomes so overwhelmed with water that the treatment plant can’t process it fast enough. So the treatment plant has to release the excess water through its discharge pipes—directly, without treatment, into streams, rivers and the ocean.
The 1.2 trillion gallons of CSO releases isn’t even the full picture. There are also discharges from poorly maintained septic systems, cesspools and busted pipes of the aging wastewater infrastructure. The state of Hawaii alone has 88,000 cesspools that need replacing and are currently leaking 53 million gallons of raw sewage daily into their coastal waters. You may think twice about swimming on your Hawaii vacations.
Overall, the US is facing a $271 billion backlog in wastewater infrastructure projects to update these aging systems. Across the Western world, countries are facing similar challenges with their aging sewage systems, especially the UK and European Union.
That’s not to say that other parts of the planet are in better shape. Out of the 7+ billion people populating our earth, 4.2 billion don’t have access to safe sanitation. Included in this insane number are roughly 2 billion people who have no toilet at all. Whether washed by rains or dumped directly into the waterways, a lot of this sludge pollutes the environment, the drinking water, and ultimately the ocean.
Pipes pour water onto a rocky shore in Jakarta, Indonesia.
Tom Fisk
What complicates this from an ocean health perspective is that it’s not just poop and pee that gets dumped into nearby waterways. It is all the things we put in and on our bodies and flush down our drains. That vicious mix of chemicals includes caffeine, antibiotics, antidepressants, painkillers, hormones, microplastics, cocaine, cooking oils, paint thinners, and PFAS—the forever chemicals present in everything from breathable clothing to fire retardant fabrics of our living room couches. Recent reports have found all of the above substances in fish—and then some.
Why do we allow so much untreated sewage spill into the sea? Frankly speaking, for decades scientists and engineers thought that the ocean could handle it. The mantra back then was “dilution is the solution to pollution,” which might’ve worked when there were much fewer people living on earth—but not now. Today science is telling us that this old approach doesn’t hold. That marine habitats are much more sensitive than we had expected and can’t handle the amount of wastewater we are discharging into them.
The excess nitrogen and phosphorus that the sewage (and agricultural runoff) dumps into the water causes harmful algal blooms, more commonly known as red or brown tides. The water column is overtaken by tiny algae that sucks up all the oxygen from the water, creating dead zones like the big fish kills in the Gulf of Mexico. These algae also cause public health issues by releasing gases toxic to people and animals, including dementia, neurological damage, and respiratory illness. Marshes and mangroves end up with weakened root systems and start dying off. In a wastewater modeling study I published last year, we found that 31 percent of salt marshes globally were heavily polluted with human sewage. Coral reefs get riddled with disease and overgrown by seaweed.
We could convert sewage into high-value goods. It can be used to generate electricity, fertilizer, and drinking water. The technologies not only exist but are getting better and more efficient all the time.
Moreover, by way of our sewage, we managed to transmit a human pathogen—Serratia marcescens, which causes urinary, respiratory and other infections in people—to corals! Recent reports from the Florida Keys are showing white pox disease popping up in elk horn corals caused by S.marcescens, which somehow managed to jump species. Many recent studies have documented just how common this type of pollution is across the globe.
Yet, there is some good news in that abysmal sewage flow. Just like with plastic pollution, realizing that there’s a problem is the first step, so awareness is key. That’s exactly why I co-founded Ocean Sewage Alliance last year—a nonprofit that aims to “re-potty train the world” by breaking taboos in talking about the poop and pee problem, as well as uniting experts from various key sectors to work together to end sewage pollution in coastal areas.
To end this pollution, we have to change the ways we handle our sewage. Even more exciting is that by solving the sewage problem we can create all sorts of economic benefits. In 2015, human poop was valued at $9.5 billion a year globally, which today would be $11.5 billion per year.
What would one do with that sh$t?
We could convert it into high-value goods. Sewage can be used to generate electricity, fertilizer, and drinking water. The technologies not only exist but are getting better and more efficient all the time. Some exciting examples include biodigesters and urine diversion (or peecycling) systems that can produce fertilizer and biogas, essentially natural gas. The United Nations estimates that the biogas produced from poop could provide electricity for 138 million homes. And the recovered and cleaned water can be used for irrigation, laundry and flushing toilets. It can even be refined to the point that it is safe for drinking water – just ask the folks in Orange County, CA who have been doing so for the last few decades.
How do we deal with all the human-made pollutants in our sewage? There is technology for that too. Called pyrolysis, it heats up sludge to high temperatures in the absence of oxygen, which causes most of the substances to degrade and fall apart.
There are solutions to the problems—as long as we acknowledge that the problems exist. The fact that you are reading this means that you are part of the solution already. The next time you flush your toilet, think about where this output may flow. Does your septic system work properly? Does your local treatment plant discharge raw sewage on rainy days? Can that plant implement newer technologies that can upcycle waste? These questions are part of re-potty training the world, one household at a time. And together, these households are the force that can turn back the toxic sewage tide. And keep our oceans blue.
The U.S. must fund more biotech innovation – or other countries will catch up faster than you think
The U.S. has approximately 58 percent of the market share in the biotech sector, followed by China with 11 percent. However, this market share is the result of several years of previous research and development (R&D) – it is a present picture of what happened in the past. In the future, this market share will decline unless the federal government makes investments to improve the quality and quantity of U.S. research in biotech.
The effectiveness of current R&D can be evaluated in a variety of ways such as monies invested and the number of patents filed. According to the UNESCO Institute for Statistics, the U.S. spends approximately 2.7 percent of GDP on R&D ($476,459.0M), whereas China spends 2 percent ($346,266.3M). However, investment levels do not necessarily translate into goods that end up contributing to innovation.
Patents are a better indication of innovation. The biotech industry relies on patents to protect their investments, making patenting a key tool in the process of translating scientific discoveries that can ultimately benefit patients. In 2020, China filed 1,497,159 patents, a 6.9 percent increase in growth rate. In contrast, the U.S. filed 597,172, a 3.9 percent decline. When it comes to patents filed, China has approximately 45 percent of the world share compared to 18 percent for the U.S.
So how did we get here? The nature of science in academia allows scientists to specialize by dedicating several years to advance discovery research and develop new inventions that can then be licensed by biotech companies. This makes academic science critical to innovation in the U.S. and abroad.
Academic scientists rely on government and foundation grants to pay for R&D, which includes salaries for faculty, investigators and trainees, as well as monies for infrastructure, support personnel and research supplies. Of particular interest to academic scientists to cover these costs is government support such as Research Project Grants, also known as R01 grants, the oldest grant mechanism from the National Institutes of Health. Unfortunately, this funding mechanism is extremely competitive, as applications have a success rate of only about 20 percent. To maximize the chances of getting funded, investigators tend to limit the innovation of their applications, since a project that seems overambitious is discouraged by grant reviewers.
Considering the difficulty in obtaining funding, the limited number of opportunities for scientists to become independent investigators capable of leading their own scientific projects, and the salaries available to pay for scientists with a doctoral degree, it is not surprising that the U.S. is progressively losing its workforce for innovation.
This approach affects the future success of the R&D enterprise in the U.S. Pursuing less innovative work tends to produce scientific results that are more obvious than groundbreaking, and when a discovery is obvious, it cannot be patented, resulting in fewer inventions that go on to benefit patients. Even though there are governmental funding options available for scientists in academia focused on more groundbreaking and translational projects, those options are less coveted by academic scientists who are trying to obtain tenure and long-term funding to cover salaries and other associated laboratory expenses. Therefore, since only a small percent of projects gets funded, the likelihood of scientists interested in pursuing academic science or even research in general keeps declining over time.
Efforts to raise the number of individuals who pursue a scientific education are paying off. However, the number of job openings for those trainees to carry out independent scientific research once they graduate has proved harder to increase. These limitations are not just in the number of faculty openings to pursue academic science, which are in part related to grant funding, but also the low salary available to pay those scientists after they obtain their doctoral degree, which ranges from $53,000 to $65,000, depending on years of experience.
Thus, considering the difficulty in obtaining funding, the limited number of opportunities for scientists to become independent investigators capable of leading their own scientific projects, and the salaries available to pay for scientists with a doctoral degree, it is not surprising that the U.S. is progressively losing its workforce for innovation, which results in fewer patents filed.
Perhaps instead of encouraging scientists to propose less innovative projects in order to increase their chances of getting grants, the U.S. government should give serious consideration to funding investigators for their potential for success -- or the success they have already achieved in contributing to the advancement of science. Such a funding approach should be tiered depending on career stage or years of experience, considering that 42 years old is the median age at which the first R01 is obtained. This suggests that after finishing their training, scientists spend 10 years before they establish themselves as independent academic investigators capable of having the appropriate funds to train the next generation of scientists who will help the U.S. maintain or even expand its market share in the biotech industry for years to come. Patenting should be given more weight as part of the academic endeavor for promotion purposes, or governmental investment in research funding should be increased to support more than just 20 percent of projects.
Remaining at the forefront of biotech innovation will give us the opportunity to not just generate more jobs, but it will also allow us to attract the brightest scientists from all over the world. This talented workforce will go on to train future U.S. scientists and will improve our standard of living by giving us the opportunity to produce the next generation of therapies intended to improve human health.
This problem cannot rely on just one solution, but what is certain is that unless there are more creative changes in funding approaches for scientists in academia, eventually we may be saying “remember when the U.S. was at the forefront of biotech innovation?”