Scientists Are Devising Clever Solutions to Feed Astronauts on Mars Space Flights
Astronaut and Expedition 64 Flight Engineer Soichi Noguchi of the Japan Aerospace Exploration Agency displays Extra Dwarf Pak Choi plants growing aboard the International Space Station. The plants were grown for the Veggie study which is exploring space agriculture as a way to sustain astronauts on future missions to the Moon or Mars.
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.
Frequent, thorough handwashing is essential to protecting yourself from infection.
What's the case-fatality rate?
Currently, the official rate is 3.4%. But this is likely way too high. China was hit particularly hard, and their healthcare system was overwhelmed. The best data we have is from South Korea. The Koreans tested 210,000 people and detected the virus in 7,478 patients. So far, the death toll is 53, which is a case-fatality rate of 0.7%. This is seven times worse than the seasonal flu (which has a case-fatality rate of 0.1%).
What's the best way to clean your hands? Soap and water? Hand sanitizer?
Soap and water is always best. Be sure to wash your hands thoroughly. (The CDC recommends 20 seconds.) If soap and water are not available, the CDC says to use hand sanitizer that is at least 60% alcohol. The problem with hand sanitizer, however, is that people neither use enough nor spread it over their hands properly. Also, the sanitizer should be covering your hands for 10-15 seconds, not evaporating before that.
How often should I wash my hands?
You should wash your hands after being in a public place, before you eat, and before you touch your face. It's a good idea to wash your hands after handling money and your cell phone, too.
How long can coronavirus live on surfaces?
It depends on the surface. According to the New York Times, "[C]old and flu viruses survive longer on inanimate surfaces that are nonporous, like metal, plastic and wood, and less on porous surfaces, like clothing, paper and tissue." According to the Journal of Hospital Infection, human coronaviruses "can persist on inanimate surfaces like metal, glass or plastic for up to 9 days, but can be efficiently inactivated by surface disinfection procedures with 62–71% ethanol, 0.5% hydrogen peroxide or 0.1% sodium hypochlorite within 1 minute." (Note: Sodium hypochlorite is bleach.)
Can Lysol wipes kill it?
Maybe not. It depends on the active ingredient. Many Lysol products use benzalkonium chloride, which the aforementioned Journal of Hospital Infection paper said was "less effective." The EPA has released a list of disinfectants recommended for use against coronavirus.
Should you wear a mask in public?
The CDC does not recommend that healthy people wear a mask in public. The benefit is likely small. However, if you are sick, then you should wear a mask to help catch respiratory droplets as you exhale.
Will pets give it to you?
That can't be ruled out. There is a documented case of human-to-canine transmission. However, an article in LiveScience explains that canine-to-human is unlikely.
Are there any "normal" things we are doing that make things worse?
Yes! Not washing your hands!!
What does it mean that previously cleared people are getting sick again? Is it the virus within or have they caught it via contamination?
It's not entirely clear. It could be that the virus was never cleared to begin with. Or it could be that the person was simply infected again. That could happen if the antibodies generated don't last long.
Will the virus go away with the weather/summer?
Quite likely, yes. Cold and flu viruses don't do well outside in summer weather. (For influenza, the warm weather causes the viral envelope to become a liquid, and it can no longer protect the virus.) That's why cold and flu season is always during the late fall and winter. However, some experts think that it is a "false hope" that the coronavirus will disappear during the summer. We'll have to wait and see.
And will it come back in the fall/winter?
That's a likely outcome. Again, we'll have to wait and see. Some epidemiologists think that COVID-19 will become seasonal like influenza.
Does dry or humid air make a difference?
Flu viruses prefer cold, dry weather. That could be true of coronaviruses, too.
What is the incubation period?
According to the World Health Organization, it's about 5 days. But it could be anywhere from 1 to 14 days.
Should you worry about sitting next to asymptomatic people on a plane or train?
It's not possible to tell if an asymptomatic person is infected or not. That's what makes asymptomatic people tricky. Just be cautious. If you're worried, treat everyone like they might be infected. Don't let them get too close or cough in your face. Be sure to wash your hands.
Should you cancel air travel planned in the next 1-2 months in the U.S.?
There are no hard and fast rules. Use common sense. Avoid hotspots of infection. If you have a trip planned to Wuhan, you might want to wait on that one. If you have a trip planned to Seattle and you're over the age of 60 and/or have an underlying health condition, you may want to hold off on that, too. If you do fly on a plane, former FDA commissioner Dr. Scott Gottlieb recommends cleaning the back of your seat and other close contact areas with antiseptic wipes. He also refuses to take anything handed out by flight attendants, since he says the biggest route of transmission comes from touching contaminated surfaces (and then touching your face).
There have been reports of an escalation of hate crimes towards Asian Americans. Can the microbiologist help illuminate that this disease has impacted all racial groups?
People might be racist, but COVID-19 is not. It can infect anyone. Older people (i.e., 60 years and older) and those with underlying health conditions are most at risk. Interestingly, young people (aged 9 and under) are minimally impacted.
To what extent/if any should toddlers -- who put everything in mouth -- avoid group classes like Gymboree?
If they get infected, toddlers will probably experience only a mild illness. The problem is if the toddler then infects somebody at higher risk, like grandpa or grandma.
Should I avoid events like concerts or theater performances if I live in a place where there is known coronavirus?
It's not an unreasonable thing to do.
Any special advice or concerns for pregnant women?
There isn't good data on this. Previous evidence, reported by the CDC, suggests that pregnant women may be more susceptible to respiratory viruses.
Advice for residents of long-term care facilities/nursing homes?
Remind the nurse or aide to constantly wash their hands.
Can we eat at Chinese restaurants? Does eating onions kill viruses? Can I take an Uber and be safe from infection?
Yes. No. Does the Uber driver or previous passengers have coronavirus? It's not possible to tell. So, treat an Uber like a public space and behave accordingly.
What public spaces should we avoid?
That's hard to say. Some people avoid large gatherings, others avoid leaving the house. Ultimately, it's going to depend on who you are and what sort of risk you're willing to take. (For example, are you young and healthy or old and sick?) I would be willing to do things that I would advise older people avoid, like going to a sporting event.
What are the differences between the L strain and the S strain?
That's not entirely clear, and it's not even clear that they are separate strains. There are some genetic differences between them. However, just because RNA viruses mutate doesn't necessarily mean that the virus will mutate to something more dangerous or unrecognizable by our immune system. The measles virus mutates, but it more or less remains the same, which is why a single vaccine could eradicate it – if enough people actually were willing to get a measles shot.
Should I wear disposable gloves while traveling?
No. If you touch something that's contaminated, the virus will be on your glove instead of your hand. If you then touch your face, you still might get sick.
The Best Coronavirus Experts to Follow on Twitter
Following these experts on social media will help you stay well-informed about the coronavirus. Global virus and disease spread, coronavirus.
As the coronavirus tears across the globe, the world's anxiety is at a fever-pitch, and we're all craving information to stay on top of the crisis.
But turning to the Internet for credible updates isn't as simple as it sounds, since we have an invisible foe spreading as quickly as the virus itself: misinformation. From wild conspiracy theories to baseless rumors, an infodemic is in full swing.
For the latest official information, you should follow the CDC, WHO, and FDA, in addition to your local public health department. But it's also helpful to pay attention to the scientists, doctors, public health experts and journalists who are sharing their perspectives in real time as new developments unfold. Here's a handy guide to get you started:
VIROLOGY
Dr. Trevor Bedford/@trvrb: Scientist at the Fred Hutchinson Cancer Research Center studying viruses, evolution and immunity.
Dr. Benhur Lee/@VirusWhisperer: Professor of microbiology at the Icahn School of Medicine at Mount Sinai
Dr. Angela Rasmussen/@angie_rasmussen: Virologist and associate research scientist at Columbia University
Dr. Florian Krammer/@florian_krammer: Professor of Microbiology at the Icahn School of Medicine at Mount Sinai
EPIDEMIOLOGY:
Dr. Alice Sim/@alicesim: Infectious disease epidemiologist and consultant at the World Health Organization
Dr. Tara C. Smith/@aetiology: Infectious disease specialist and professor at Kent State University
Dr. Caitlin Rivers/@cmyeaton: Epidemiologist and assistant professor at the Johns Hopkins Bloomberg School of Public Health
Dr. Michael Mina/@michaelmina_lab: Physician and Assistant Professor of Epidemiology & Immunology at the Harvard TH Chan School of Public Health
INFECTIOUS DISEASE:
Dr. Nahid Bhadelia/@BhadeliaMD: Infectious diseases physician and the medical director of Special Pathogens Unit at Boston University School of Medicine
Dr. Paul Sax/@PaulSaxMD: Clinical Director of the Division of Infectious Diseases at Brigham and Women's Hospital
Dr. Priya Sampathkumar/@PsampathkumarMD: Infectious Disease Specialist at the Mayo Clinic
Dr. Krutika Kuppalli/@KrutikaKuppalli: Medical doctor and Infectious Disease Specialist based in Palo Alto, CA
PANDEMIC PREP:
Dr. Syra Madad/@syramadad: Senior Director, System-wide Special Pathogens Program at New York City Health + Hospitals
Dr Sylvie Briand/@SCBriand: Director of Pandemic and Epidemic Diseases Department at the World Health Organization
Jeremy Konyndyk/@JeremyKonyndyk: Senior Policy Fellow at the Center for Global Development
Amesh Adalja/@AmeshAA: Senior Scholar at the Johns Hopkins University Center for Health Security
PUBLIC HEALTH:
Scott Becker/@scottjbecker: CEO of the Association of Public Health Laboratories
Dr. Scott Gottlieb/@ScottGottliebMD: Physician, former commissioner of the Food and Drug Administration
APHA Public Health Nursing/@APHAPHN: Public Health Nursing Section of the American Public Health Association
Dr. Tom Inglesby/@T_Inglesby: Director of the Johns Hopkins SPH Center for Health Security
Dr. Nancy Messonnier/@DrNancyM_CDC: Director of the Center for the National Center for Immunization and Respiratory Diseases (NCIRD)
Dr. Arthur Caplan/@ArthurCaplan: Professor of Bioethics at New York University Langone Medical Center
SCIENCE JOURNALISTS:
Laura Helmuth/@laurahelmuth: Incoming Editor in Chief of Scientific American
Helen Branswell/@HelenBranswell: Infectious disease and public health reporter at STAT
Sharon Begley/@sxbegle: Senior writer at STAT
Carolyn Johnson/@carolynyjohnson: Science reporter at the Washington Post
Amy Maxmen/@amymaxmen: Science writer and senior reporter at Nature
Laurie Garrett/@Laurie_Garrett: Pulitzer-prize winning science journalist, author of The Coming Plague, former senior fellow for global health at the Council on Foreign Relations
Soumya Karlamangla/@skarlamangla: Health writer at the Los Angeles Times
André Picard/@picardonhealth: Health Columnist, The Globe and Mail
Caroline Chen/@CarolineYLChen: Healthcare reporter at ProPublica
Andrew Jacobs/@AndrewJacobsNYT: Science reporter at the New York Times
Meg Tirrell/@megtirrell: Biotech and pharma reporter for CNBC
Kira Peikoff was the editor-in-chief of Leaps.org from 2017 to 2021. As a journalist, her work has appeared in The New York Times, Newsweek, Nautilus, Popular Mechanics, The New York Academy of Sciences, and other outlets. She is also the author of four suspense novels that explore controversial issues arising from scientific innovation: Living Proof, No Time to Die, Die Again Tomorrow, and Mother Knows Best. Peikoff holds a B.A. in Journalism from New York University and an M.S. in Bioethics from Columbia University. She lives in New Jersey with her husband and two young sons. Follow her on Twitter @KiraPeikoff.