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.
Forcing Vaccination on Every Child Undermines Civil Liberties
[Editor's Note: This opinion essay is in response to our current Big Question, which we posed to experts with different viewpoints: "Where should society draw the line between requiring vaccinations for children and allowing parental freedom of choice?"]
Our children are the future. The survival of humanity is advanced by the biological imperative that mothers and fathers want and need to protect their children and other children from being harmed for any reason.
Science is not perfect, doctors are not infallible, and medical interventions come with risks.
In the 21st century, consensus science considers vaccination to be one of the greatest inventions in the history of medicine and the greatest achievement of public health programs. The national vaccination rate for U.S. kindergarten children is 94 percent and most children today receive 69 doses of 16 federally recommended vaccines. However, public health is not simply measured by high vaccination rates and absence of infectious disease, which is evidenced by the chronic inflammatory disease and disability epidemic threatening to bankrupt the U.S. health care system.
Science is not perfect, doctors are not infallible, and medical interventions come with risks, which is why parents have the power to exercise informed consent to medical risk taking on behalf of their minor children.
As a young mother, I learned that vaccine risks are 100 percent for some children because, while we are all born equal under the law, we are not born all the same. Each one of us enters this world with different genes, a unique microbiome and epigenetic influences that affect how we respond to the environments in which we live. We do not all respond the same way to infectious diseases or to pharmaceutical products like vaccines.
Few parents were aware of vaccine side effects in 1980, when my bright, healthy two-and-a-half year-old son, Chris, suffered a convulsion, collapse, and state of unconsciousness (encephalopathy) within hours of his fourth DPT shot, and then regressed physically, mentally and emotionally and became a totally different child. Chris was eventually diagnosed with multiple learning disabilities and confined to a special education classroom throughout his public school education, but he and I both know his vaccine reaction could have been much worse. Today, Chris is an independent adult but many survivors of brain injury are not.
Barbara Loe Fisher and her son, Chris, in December 1981 after his fourth DPT shot.
(Courtesy Fisher)
The public conversation about several hundred cases of measles reported in the U.S. this year is focused on whether every parent has a social obligation to vaccinate every child to maintain "community immunity," but vaccine failures are rarely discussed. Emerging science reveals that there are differences in naturally and vaccine acquired immunity, and both vaccinated and unvaccinated children and adults transmit infections, sometimes with few or no symptoms.
Nearly 40 percent of cases reported in the 2015 U.S. measles outbreak occurred in recently vaccinated individuals who developed vaccine reactions that appeared indistinguishable from measles. Outbreaks of pertussis (whooping cough) in highly vaccinated child populations have been traced to waning immunity and evolution of the B. pertussis microbe to evade the vaccines. Influenza vaccine effectiveness was less than 50 percent in 11 of the past 15 flu seasons.
Vaccine policymakers recognize that children with severe combined immune deficiency or those undergoing chemotherapy or organ transplants are at increased risk for complications of infectious diseases and vaccines. However, there is no recognition of the risks to healthy infants and children with unidentified susceptibility to vaccine reactions, including children whose health suddenly deteriorates without explanation after vaccination. Medical care is being denied to children and adults in the U.S. if even one government recommended vaccination is declined, regardless of health or vaccine reaction history.
When parents question the risks and failures of a commercial pharmaceutical product being mandated for every child, the answer is not more force but better science and respect for the informed consent ethic.
The social contract we have with each other when we live in communities, whether we belong to the majority or a minority, is to care about and protect every individual living in the community. One-size-fits-all vaccine policies and laws, which fail to respect biodiversity and force everyone to be treated the same, place an unequal risk burden on a minority of unidentified individuals unable to survive vaccination without being harmed.
A law that requires certain minorities to bear a greater risk of injury or sacrifice their lives in service to the majority is not just or moral.
Between 1991 and 2013, the Institute of Medicine (IOM) published reports documenting that vaccines can cause brain inflammation and other serious reactions, injuries and death. A 2012 IOM report acknowledged that there are genetic, biological, and environmental risk factors that make some individuals more susceptible to adverse responses to vaccines but often doctors cannot identify who they are because of gaps in vaccine science. Congress acknowledged this fact a quarter century earlier in the 1986 National Childhood Vaccine Injury Act, which created a federal vaccine injury compensation program alternative to a lawsuit that has awarded more than $4 billion to vaccine-injured children and adults.
We give up the human right to autonomy and informed consent at our peril, no matter where or in what century we live.
Vaccine manufacturers and administrators have liability protection, yet today almost no health condition qualifies for a medical vaccine exemption under government guidelines. Now, there is a global call by consensus science advocates for elimination of all personal belief vaccine exemptions and censorship of books and public conversations that criticize vaccine safety or government vaccine policy. Some are calling for quarantine of all who refuse vaccinations and criminal prosecution, fines and imprisonment of parents with unvaccinated children, as well as punishment of doctors who depart from government policy.
There is no civil liberty more fundamentally a natural, inalienable right than exercising freedom of thought and conscience when deciding when and for what reason we are willing to risk our life or our child's life. That is why voluntary, informed consent to medical risk-taking has been defined as a human right governing the ethical practice of modern medicine.
In his first Presidential inaugural address, Thomas Jefferson warned:
"All, too, will bear in mind this sacred principle, that though the will of the majority is in all cases to prevail, that will to be rightful must be reasonable; that the minority posses their equal rights, which equal law must protect, and to violate would be oppression."
The seminal 1905 U.S. Supreme Court decision, Jacobson v. Massachusetts, affirmed the constitutional authority of states to enact mandatory smallpox vaccination laws. However, the justices made it clear that implementation of a vaccination law should not become "cruel and inhuman to the last degree." They warned, "All laws, this court has said, should receive a sensible construction. General terms should be so limited in their application as not to lead to injustice, oppression, or an absurd consequence. It will always, therefore, be presumed that the legislature intended exceptions to its language, which would avoid results of this character."
Mothers and fathers, who know and love their children better than anyone else, depend upon sound science and compassionate public health policies to help them protect their own and other children from harm. If individuals susceptible to vaccine injury cannot be reliably identified, the accuracy of vaccine benefit and risk calculations must be reexamined. Yet, consensus science and medicine around vaccination discourages research into the biological mechanisms of vaccine injury and death and identification of individual risk factors to better inform public health policy.
A critic of consensus science, physician and author Michael Crichton said, "Let's be clear: the work of science has nothing whatever to do with consensus. Consensus is the business of politics. Period."
Condoning elimination of civil liberties, including freedom of speech and the right to dissent guaranteed under the First Amendment of the U.S. Constitution, to enforce vaccination creates a slippery slope. Coercion, punishment and censorship will destroy, not instill, public trust in the integrity of medical practice and public health laws.
There are more than a dozen new vaccines being fast tracked to market by industry and governments. Who in society should be given the power to force all children to use every one of them without parental consent regardless of how small or great the risk?
We give up the human right to autonomy and informed consent at our peril, no matter where or in what century we live. Just and compassionate public health laws that protect parental and human rights will include flexible medical, religious and conscientious belief vaccine exemptions to affirm the informed consent ethic and prevent discrimination against vulnerable minorities.
[Editor's Note: Read the opposite viewpoint here.]
Not Vaccinating Your Kids Endangers Public Health
[Editor's Note: This opinion essay is in response to our current Big Question, which we posed to experts with different viewpoints: "Where should society draw the line between requiring vaccinations for children and allowing parental freedom of choice?"]
Society has a right and at times an obligation to require children to be vaccinated. Vaccines are one of the most effective medical and public health interventions. They save lives and prevent suffering. The vast majority of parents in the United States fully vaccinate their children according to the recommended immunization schedule. These parents are making decisions so that the interests of their children and the interest of society are the same. There are no ethical tensions.
"Measles is only a plane ride away from American children."
A strong scientific basis supports the recommended immunization schedule. The benefits of recommended vaccines are much bigger than the risks. However, a very small proportion of parents are ideologically opposed to vaccines. A slightly larger minority of parents do not believe that all of the recommended vaccines are in their child's best interests.
Forgoing vaccinations creates risk to the child of contracting diseases. It also creates risk to communities and vulnerable groups of people who cannot be vaccinated because of their age or health status.
For example, many vaccines are not able to be given to newborns, such as the measles vaccine which is recommended at 12-15 months of age, leaving young children vulnerable. Many diseases are particularly dangerous for young children. There are also some children who can't be vaccinated, such as pediatric cancer patients who are undergoing chemotherapy or radiation treatment. These children are at increased risk of serous complication or death.
Then there are people who are vaccinated but remain susceptible to disease because no vaccine is 100% effective. In the case of measles, two doses of vaccines protect 97% of people, leaving 3% still susceptible even after being fully vaccinated. All of these groups of people – too young, not eligible, and vaccinated but still susceptible – are dependent on almost everyone else to get vaccinated in order for them to be protected.
Sadly, even though measles has been largely controlled because most people get the very safe and very effective vaccine, we are now seeing dangerous new outbreaks because some parents are refusing vaccines for their children, especially in Europe. Children have died. Measles is only a plane ride away from American children.
There have been repeated measles outbreaks in the United States – such as the Disneyland outbreak and six outbreaks already this year - because of communities where too many parents refuse the vaccine and measles is brought over, often from Europe.
The public health benefits cannot be emphasized enough: Vaccines are not just about protecting your child. Vaccines protect other children and the entire community. Vaccine-preventable diseases (with the exception of tetanus) are spread from person to person. The decision of a parent to not vaccinate their child can endanger other children and vulnerable people.
As a vaccine safety researcher for 20 years, I believe that the community benefit of vaccination can provide justification to limit parental autonomy.
Given these tensions between parental autonomy and the protective value of vaccines, the fundamental question remains: Should society require all children to submit to vaccinations? As a vaccine safety researcher for 20 years, I believe that the community benefit of vaccination can provide justification to limit parental autonomy.
In the United States, we see this balancing act though state requirements for vaccinations to enter school and the varying availability of non-medical exemptions to these laws. Mandatory vaccination in the United States are all state laws. All states require children entering school to receive vaccines and permit medical exemptions. There are a lot of differences between states regarding which vaccines are required, target populations (daycare, school entry, middle school, college), and existence and types of non-medical (religious or philosophical) exemptions that are permitted.
Amid recent measles outbreaks, for instance, California eliminated all non-medical exemptions, making it one of three states that only permit medical exemptions. The existence and enforcement of these school laws reflect broad public support for vaccines to protect the community from disease outbreaks.
I worry about how many kids must suffer, and even die, from diseases like measles until enough is enough. Such tragedies have no place in the modern era. All parents want to do right by their children. All parents deserve autonomy when it comes to decision-making. But when their choices confer serious risks to others, the buck should stop. Our nation would be better off—both medically and ethically—if we did not turn our backs on our most vulnerable individuals.
[Editor's Note: Read the opposite viewpoint here.]