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.
New gene therapy helps patients with rare disease. One mother wouldn't have it any other way.
Three years ago, Jordan Janz of Consort, Alberta, knew his gene therapy treatment for cystinosis was working when his hair started to darken. Pigmentation or melanin production is just one part of the body damaged by cystinosis.
“When you have cystinosis, you’re either a redhead or a blonde, and you are very pale,” attests Janz, 23, who was diagnosed with the disease just eight months after he was born. “After I got my new stem cells, my hair came back dark, dirty blonde, then it lightened a little bit, but before it was white blonde, almost bleach blonde.”
According to Cystinosis United, about 500 to 600 people have the rare genetic disease in the U.S.; an estimated 20 new cases are diagnosed each year.
Located in Cambridge, Mass., AVROBIO is a gene therapy company that targets cystinosis and other lysosomal storage disorders, in which toxic materials build up in the cells. Janz is one of five patients in AVROBIO’s ongoing Phase 1/2 clinical trial of a gene therapy for cystinosis called AVR-RD-04.
Recently, AVROBIO compiled positive clinical data from this first and only gene therapy trial for the disease. The data show the potential of the therapy to genetically modify the patients’ own hematopoietic stem cells—a certain type of cell that’s capable of developing into all different types of blood cells—to express the functional protein they are deficient in. It stabilizes or reduces the impact of cystinosis on multiple tissues with a single dose.
Medical researchers have found that more than 80 different mutations to a gene called CTNS are responsible for causing cystinosis. The most common mutation results in a deficiency of the protein cystinosin. That protein functions as a transporter that regulates a lot metabolic processes in the cells.
“One of the first things we see in patients clinically is an accumulation of a particular amino acid called cystine, which grows toxic cystine crystals in the cells that cause serious complications,” explains Essra Rihda, chief medical officer for AVROBIO. “That happens in the cells across the tissues and organs of the body, so the disease affects many parts of the body.”
Jordan Janz, 23, meets Stephanie Cherqui, the principal investigator of his gene therapy trial, before the trial started in 2019.
Jordan Janz
According to Rihda, although cystinosis can occur in kids and adults, the most severe form of the disease affects infants and makes up about 95 percent of overall cases. Children typically appear healthy at birth, but around six to 18 months, they start to present for medical attention with failure to thrive.
Additionally, infants with cystinosis often urinate frequently, a sign of polyuria, and they are thirsty all the time, since the disease usually starts in the kidneys. Many develop chronic kidney disease that ultimately progresses to the point where the kidney no longer supports the body’s needs. At that stage, dialysis is required and then a transplant. From there the disease spreads to many other organs, including the eyes, muscles, heart, nervous system, etc.
“The gene for cystinosis is expressed in every single tissue we have, and the accumulation of this toxic buildup alters all of the organs of the patient, so little by little all of the organs start to fail,” says Stephanie Cherqui, principal investigator of Cherqui Lab, which is part of UC San Diego’s Department of Pediatrics.
Since the 1950s, a drug called cysteamine showed some therapeutic effect on cystinosis. It was approved by the FDA in 1994 to prevent damage that may be caused by the buildup of cystine crystals in organs. Prior to FDA approval, Cherqui says, children were dying of the disease before they were ten-years-old or after a kidney transplant. By taking oral cysteamine, they can live from 20 to 50 years longer. But it’s a challenging drug because it has to be taken every 6 or 12 hours, and there are serious gastric side effects such as nausea and diarrhea.
“With all of the complications they develop, the typical patient takes 40 to 60 pills a day around the clock,” Cherqui says. “They literally have a suitcase of medications they have to carry everywhere, and all of those medications don’t stop the progression of the disease, and they still die from it.”
Cherqui has been a proponent of gene therapy to treat children’s disorders since studying cystinosis while earning her doctorate in 2002. Today, her lab focuses on developing stem cell and gene therapy strategies for degenerative, hereditary disorders such as cystinosis that affect multiple systems of the body. “Because cystinosis expresses in every tissue in the body, I decided to use the blood-forming stem cells that we have in our bone marrow,” she explains. “These cells can migrate to anywhere in the body where the person has an injury from the disease.”
AVROBIO’s hematopoietic stem cell gene therapy approach collects stem cells from the patient’s bone marrow. They then genetically modify the stem cells to give the patient a copy of the healthy CTNS gene, which the person either doesn’t have or it’s defective.
The patient first undergoes apheresis, a medical procedure in which their blood is passed through an apparatus that separates out the diseased stem cells, and a process called conditioning is used to help eliminate the damaged cells so they can be replaced by the infusion of the patient’s genetically modified stem cells. Once they become engrafted into the patient’s bone marrow, they reproduce into a lot of daughter cells, and all of those daughter cells contain the CTNS gene. Those cells are able to express the healthy, functional, active protein throughout the body to correct the metabolic problem caused by cystinosis.
“What we’re seeing in the adult patients who have been dosed to date is the consistent and sustained engraftment of our genetically modified cells, 17 to 27 months post-gene therapy, so that’s very encouraging and positive,” says Rihda, the chief medical officer at AVROBIO.
When Janz was 11-years-old, his mother got him enrolled in the trial of a new form of cysteamine that would only need to be taken every 12 hours instead of every six. Two years later, she made sure he was the first person on the list for Cherqui’s current stem cell gene therapy trial.
AVROBIO researchers have also confirmed stabilization or improvement in motor coordination and visual perception in the trial participants, suggesting a potential impact on the neuropathology of the disease. Data from five dosed patients show strong safety and tolerability as well as reduced accumulation of cystine crystals in cells across multiple tissues in the first three patients. None of the five patients need to take oral cysteamine.
Janz’s mother, Barb Kulyk, whom he credits with always making him take his medications and keeping him hydrated, had been following Cherqui’s research since his early childhood. When Janz was 11-years-old, she got him enrolled in the trial of a new form of cysteamine that would only need to be taken every 12 hours instead of every six. When he was 17, the FDA approved that drug. Two years later, his mother made sure he was the first person on the list for Cherqui’s current stem cell gene therapy trial. He received his new stem cells on October 7th, 2019, went home in January 2020, and returned to working full time in February.
Jordan Janz, pictured here with his girlfriend, has a new lease on life, plus a new hair color.
Jordan Janz
He notes that his energy level is significantly better, and his mother has noticed much improvement in him and his daily functioning: He rarely vomits or gets nauseous in the morning, and he has more color in his face as well as his hair. Although he could finish his participation at any time, he recently decided to continue in the clinical trial.
Before the trial, Janz was taking 56 pills daily. He is completely off all of those medications and only takes pills to keep his kidneys working. Because of the damage caused by cystinosis over the course of his life, he’s down to about 20 percent kidney function and will eventually need a transplant.
“Some day, though, thanks to Dr. Cherqui’s team and AVROBIO’s work, when I get a new kidney, cystinosis won’t destroy it,” he concludes.
New study: Hotter nights, climate change, cause sleep loss with some affected more than others
Data from the National Sleep Foundation finds that the optimal bedroom temperature for sleep is around 65 degrees Fahrenheit. But we may be getting fewer hours of "good sleepin’ weather" as the climate warms, according to a recent paper from researchers at the University of Copenhagen, Denmark.
Published in One Earth, the study finds that heat related to climate change could provide a “pathway” to sleep deprivation. The authors say the effect is “substantially larger” for those in lower-income countries. Hours of sleep decline when nighttime temperature exceeds 50 degrees, and temps higher than 77 reduce the chances of sleeping for seven hours by 3.5 percent. Even small losses associated with rising temperatures contribute significantly to people not getting enough sleep.
We’re affected by high temperatures at night because body temperature becomes more sensitive to the environment when slumbering. “Mechanisms that control for thermal regulation become more disordered during sleep,” explains Clete Kushida, a neurologist, professor of psychiatry at Stanford University and sleep medicine clinician.
The study finds that women and older adults are especially vulnerable. Worldwide, the elderly lost over twice as much sleep per degree of warming compared to younger people. This phenomenon was apparent between the ages of 60 and 70, and it increased beyond age 70. “The mechanism for balancing temperatures appears to be more affected with age,” Kushida adds.
Others disproportionately affected include those who live in regions with more greenhouse gas (GHG) emissions, which accelerate climate change, and people in hotter locales will lose more sleep per degree of warming, according to the study, with suboptimal temperatures potentially eroding 50 to 58 hours of sleep per person per year. One might think that those in warmer countries can adapt to the heat, but the researchers found no evidence for such adjustments. “We actually found those living in the warmest climate regions were impacted over twice as much as those in the coldest climate regions,” says the study's lead author, Kelton Minor, a Ph.D. candidate at the University of Copenhagen’s Center for Social Data Science.
Short sleep can reduce cognitive performance and productivity, increase absenteeism from work or school, and lead to a host of other physical and psychosocial problems. These issues include a compromised immune system, hypertension, depression, anger and suicide, say the study’s authors. According to a fact sheet by the U.S. Centers for Disease Control and Prevention, a third of U.S. adults already report sleeping fewer hours than the recommended amount, even though sufficient sleep “is not a luxury—it is something people need for good health.”
Equitable policy and planning are needed to ensure equal access to cooling technologies in a warming world.
Beyond global health, a sleep-deprived world will impact the economy as the climate warms. “Less productivity at work, associated with sleep loss or deprivation, would result in more sick days on a global scale, not just in individual countries,” Kushida says.
Unlike previous research that measured sleep patterns with self-reported surveys and controlled lab experiments, the study in One Earth offers a global analysis that relies on sleep-tracking wristbands that link more than seven million sleep records of 47,628 adults across 68 countries to local and daily meteorological data, offering new insight into the environmental impact on human sleep. Controlling for individual, seasonal and time-varying confounds, researchers found the main way that higher temperatures shorten slumber is by delaying sleep onset.
Heat effects on sleep were seen in industrialized countries including those with access to air conditioning, notes the study. Air conditioning may buffer high indoor temperatures, but they also increase GHG emissions and ambient heat displacement, thereby exacerbating the unequal burdens of global and local warming. Continued urbanization is expected to contribute to these problems.
Previous sleep studies have found an inverse U-shaped response to temperature in highly controlled settings, with subjects sleeping worse when room temperatures were either too cold or too warm. However, “people appear far better at adapting to colder outside temperatures than hotter conditions,” says Minor.
Although there are ways of countering the heat effect, some populations have more access to them. “Air conditioning can help with the effect of higher temperature, but not all individuals can afford air conditioners,” says Kushida. He points out that this could drive even greater inequity between higher- and lower-income countries.
Equitable policy and planning are needed to ensure equal access to cooling technologies in a warming world. “Clean and renewable energy systems and interventions will be needed to mitigate and adapt to ongoing climate warming,” Minor says. Future research should investigate “policy, planning and design innovation,” which could reduce the impact of sweltering temperatures on a good night’s sleep for the good of individuals, society and our planet, asserts the study.
Unabated and on its current trajectory, by 2099 suboptimal temperatures could shave 50 to 58 hours of sleep per person per year, predict the study authors. “Down the road, as technology develops, there might be ways of enabling people to adapt on a large scale to these higher temperatures,” says Kushida. “Right now, it’s not there.”