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.
Deaf Scientists Just Created Over 1000 New Signs to Dramatically Improve Ability to Communicate
Sarah Latchney, the first deaf PhD student at the University of Rochester School of Medicine & Dentistry, pictured here at work at a lab in the department of environmental sciences.
For the deaf, talent and hard work may not be enough to succeed in the sciences. According to the National Science Foundation, deaf Americans are vastly underrepresented in the STEM fields, a discrepancy that has profound economic implications.
The problem with STEM careers for the deaf and hard-of-hearing is that there are not enough ASL signs available.
Deaf and hard-of-hearing professionals in the sciences earn 31 percent more than those employed in other careers, according to a 2010 study by the National Technical Institute for the Deaf (NTID) in Rochester, N.Y., the largest technical college for deaf and hard-of-hearing students. But at the same time, in 2017, U.S. students with hearing disabilities earned only 1.1 percent of the 39,435 doctoral degrees awarded in science and engineering.
One reason so few deaf students gravitate to science careers and may struggle to complete doctoral programs is the communication chasm between deaf and hard-of-hearing scientists and their hearing colleagues.
Lorne Farovitch is a doctoral candidate in biomedical science at the University of Rochester of New York. Born deaf and raised by two deaf parents, he communicated solely in American Sign Language (ASL) until reaching graduate school. There, he became frustrated at the large chunk of his workdays spent communicating with hearing lab mates and professors, time he would have preferred spending on his scientific work.
The problem with STEM careers for the deaf and hard-of-hearing is that there are not enough ASL signs available, says Farovitch. Names, words, or phrases that don't exist in ASL must be finger spelled — the signer must form a distinct hand shape to correspond with each letter of the English alphabet, a tedious and time-consuming process. For instance, it requires 12 hand motions to spell out the word M-I-T-O-C-H-O-N-D-R-I-A. Imagine repeating those motions countless times a day.
To bust through this linguistic quagmire, Farovitch, along with a team of deaf STEM professionals, linguists, and interpreters, have been cooking up signs for terms like Anaplasma phagocytophilum, the tick-borne bacterium Farovitch studies. The sign creators are then videotaped performing the new signs. Those videos are posted on two crowd-sourcing sites, ASLcore.org and ASL Clear.
The beauty of ASL is you can express an entire concept in a single sign, rather than by the name of a word.
"If others don't pick it up and use it, a sign goes extinct," says Farovitch. Thus far, more than 1,000 STEM terms have been developed on ASL Clear and 500 vetted and approved by the deaf STEM community, according to Jeanne Reis, project director of the ASL Clear Project, based at The Learning Center for the Deaf in Framingham, Mass.
The beauty of ASL is you can express an entire concept in a single sign, rather than by the name of a word. The signs are generally intuitive and wonderfully creative. To express "DNA" Farovitch uses two fingers of each hand touching the tips of the opposite hand; then he draws both the hands away to suggest the double helix form of the hereditary material present in most organisms.
"If you can show it, you can understand the concept better,'' says the Canadian-born scientist. "I feel I can explain science better now."
The hope is that as ASL science vocabulary expands more, deaf and hard-of-hearing students will be encouraged to pursue the STEM fields. "ASL is not just a tool; it's a language. It's a vital part of our lives," Farovitch explains through his interpreter.
The deaf community is diverse—within and beyond the sciences. Sarah Latchney, PhD, an environmental toxicologist, is among the approximately 90 percent of deaf people born to hearing parents. Hers made sure she learned ASL at an early age but they also sent Latchney to a speech therapist to learn to speak and read lips. Latchney is so adept at both that she can communicate one-on-one with a hearing person without an interpreter.
Like Favoritch, Latchney has developed "conceptually accurate" ASL signs but she has no plans to post them on the crowd-sourcing sites. "I don't want to fix [my signs]; it works for me," she explains.
Young scientists like Farovitch and Latchney stress the need for interpreters who are knowledgeable about science. "When I give a presentation I'm a nervous wreck that I'll have an interpreter who may not have a science background," Latchney explains. "Many times what I've [signed] has been misinterpreted; either my interpreter didn't understand the question or didn't frame it correctly."
To enlarge the pool of science-savvy interpreters, the University of Rochester will offer a new masters degree program: ASL Interpreting in Medicine and Science (AIMS), which will train interpreters who have a strong background in the biological sciences.
Since the Americans with Disabilities Act was enacted in 1990, opportunities in higher education for deaf and hard-of-hearing students have opened up in the form of federally funded financial aid and the creation of student disability services on many college campuses. Still, only 18 percent of deaf adults have graduated from college, compared to 33 percent of the general population, according to a survey by the U.S. Census Bureau in 2015.
The University of Rochester and the Rochester Institute of Technology, home to NTID, have jointly created two programs to increase the representation of deaf and hard-of-hearing professionals in the sciences. The Rochester Bridges to the Doctorate Program, which Farovitch is enrolled in, prepares deaf scholars for biomedical PhD programs. The Rochester Postdoctoral Partnership readies deaf postdoctoral scientists to successfully attain academic research and teaching careers. Both programs are funded by the National Institutes of Science. In the last five years, the University of Rochester has gone from zero deaf postdoctoral and graduate students to nine.
"Deafness is not a problem, it's just a difference."
It makes sense for these two private universities to support strong programs for the deaf: Rochester has the highest per capita population of deaf or hard-of-hearing adults younger than 65 in the nation, according to the U.S. Census. According to the U.S. Department of Education, there are about 136,000 post-secondary level students who are deaf or hard of hearing.
"Deafness is not a problem, it's just a difference," says Farovitch. "We just need a different way to communicate. It doesn't mean we require more work."
Pregnant and Breastfeeding Women Might Have a New Reason to Ditch Artificial Sweeteners
A mom cradles her newborn baby.
Women considering pregnancy might have another reason to drop artificial sweeteners from their diet, if a new study of mice proves to apply to humans as well. It highlights "yet another potential health impact of zero-calorie sweeteners," according to lead author Stephanie Olivier-Van Stichelen.
The discovery was serendipitous, not part of the original study.
It found that commonly used artificial sweeteners consumed by female mice transfer to pups in the womb and later through milk, harming their development. The sweeteners affected the composition of bacteria in the gut of the pups, making them more vulnerable to developing diabetes, and greatly reduced the liver's capacity to neutralize toxins.
The discovery was serendipitous, not part of the original study, says John Hanover, the senior author and a cell biologist at the NIH National Institute of Diabetes and Digestive and Kidney Diseases. The main study looked at how a high sugar diet in the mother turns genes on and off in the developing offspring.
It compared them with mothers fed a low sugar diet, replacing sugar with a mix of sucralose and acesulfame-K (AK), two non-nutrient artificial sugars that are already used extensively in our food products and thought to be safe.
While the artificial sweeteners had little effect on the mothers, the trace amounts that were transferred through the placenta and milk had a profound effect on the pups. Hanover believes the molecules are changing gene expression during a crucial, short period of development.
"Somewhat to our surprise, we saw in the pups a really dramatic change in the microbiome" of those whose mothers were fed the artificial sweeteners, Hanover told leapsmag. "It looked like the neonates were much, much more sensitive than their mothers to the sucralose and AK." The unexpected discovery led them to publish a separate paper.
"The protective microbe Akkermansia was largely missing, and we saw a pretty dramatic shift in the ratio of two bacteria that are normally associated with metabolic disease," a precursor to diabetes, he explains. Akkermansia is a bacteria that feeds on mucus in the gut and helps remodel the tissue to an adult state over the first several months of life in a mouse. A similar process takes several years in humans, as the infant is weaned off of breast milk as the primary food source.
The good news is the body seems to remove these artificial sweeteners fairly quickly, probably within a week.
Another problem the researchers saw in the animals was "a particularly striking change in the metabolism of the detoxification systems" in the liver, says Hanover. A healthy liver is dark red, but a high dose of the artificial sweeteners turned it white, "which is a sign of massive problems."
The study was conducted in mice and Hanover cautions the findings may not apply to humans. "But in general, the microbiome changes that one sees in the rodent model mimics what we see in humans...[and] the genes that are turned on in the mouse and the human are very similar."
Hanover acknowledges the quantity of artificial sweeteners used in the study is on the high end of human consumption, roughly the equivalent of 20 cans of diet soda a day. But the sweeteners are so ubiquitous in consumer products, from foods to lipstick, and often not even mentioned on the label, that it is difficult to measure just how much a person consumes every day.
The good news is the body seems to remove these artificial sweeteners fairly quickly, probably within a week. Until further studies provide a clearer picture, women who want to err on the side of caution can choose to reduce if not eliminate their exposure to artificial sweeteners during pregnancy and breastfeeding.