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.
This spring, just like any other year, thousands of young North American engineers will graduate from their respective colleges ready to start erecting buildings, assembling machinery, and programming software, among other things. But before they take on these complex and important tasks, many of them will recite a special vow stating their ethical obligations to society, not unlike the physicians who take their Hippocratic Oath, affirming their ethos toward the patients they would treat. At the end of the ceremony, the engineers receive an iron ring, as a reminder of their promise to the millions of people their work will serve.
The ceremony isn’t just another graduation formality. As a profession, engineering has ethical weight. Moreover, engineering mistakes can be even more deadly than medical ones. A doctor’s error may cost a patient their life. But an engineering blunder may bring down a plane or crumble a building, resulting in many more fatalities. When larger projects—such as fracking, deep-sea mining or building nuclear reactors—malfunction and backfire, they can cause global disasters, afflicting millions. A vow that reminds an engineer that their work directly affects humankind and their planet is no less important than a medical oath that summons one to do no harm.
The tradition of taking an engineering oath began over a century ago in Canada. In 1922, Herbert E.T. Haultain, professor of mining engineering at the University of Toronto, presented the idea at the annual meeting of the Engineering Institute of Canada. The seven past presidents of that body were in attendance, heard Haultain’s speech and accepted his suggestion to form a committee to create an honor oath. Later, they formed the nonprofit Corporation of the Seven Wardens, which would oversee the ritual. Next year, in 1923, with the encouragement of the Seven Wardens, Haultain wrote to poet and writer Rudyard Kipling, asking him to develop a professional oath for engineers. “We are a tribe—a very important tribe within the community,” Haultain said in the letter, “but we are lacking in tribal spirit, or perhaps I should say, in manifestation of tribal spirit. Also, we are inarticulate. Can you help us?”
While Kipling is most famous now for “The Jungle Book” and perhaps his poem “Gunga Din,” he had also written a short story about engineers, “The Bridge Builders.” His poem “The Sons of Martha” can be read as a celebration of engineers:
It is their care in all the ages to take the buffet and cushion the shock.
It is their care that the gear engages; it is their care that the switches lock.
It is their care that the wheels run truly; it is their care to embark and entrain,
Tally, transport, and deliver duly the Sons of Mary by land and main.
Kipling accepted the ask and wrote the Ritual of the Calling of an Engineer, which he sent to Haultain a month later. In his response to Haultain, he stated that he preferred the word “Obligation” to “Oath.” He wrote the Obligation using Old English lettering and the old-fashioned capitalization. Kipling’s Obligation binds engineers upon their “Honor and Cold Iron” to not “suffer or pass, or be privy to the passing of, Bad Workmanship or Faulty Material,” and pardon is asked “in the presence of my betters and my equals in my Calling” for the engineer’s “assured failures and derelictions.” The hope is that when one is tempted to shoddy work by weakness or weariness, the memory of the Obligation “and the company before whom it was entered into, may return to me to aid, comfort, and restrain.”
Using the Obligation, The Seven Wardens created an induction ceremony, which seeks to unify the profession and recognize engineering’s ethics, including responsibility to the public and the need to make the best decisions possible. The induction ceremony included recitation of Kipling’s “Obligation” and incorporated an anvil, a hammer, an iron chain, and an iron ring. The inductee engineers sat inside an area marked off by the iron chain, with their more senior colleagues outside that area. At the start of the ritual, the leader beat out S-S-T in Morse code with the hammer and anvil—the letters standing for Steel, Stone, and Time. A more experienced and previously obligated engineer placed the ring on the small finger of the inductee engineer’s working hand. As per Kipling, the ring’s rough, faceted texture symbolized “the young engineer’s mind” and the difficulties engineers face in mastering their discipline.
A persistent myth purports that the original iron rings were made from the beams or bolts of the Quebec Bridge that failed twice during construction.
The first induction ceremony took place on April 25, 1925, in Montreal to obligate two of the Seven Wardens, along with four graduates from the University of Toronto class of 1893. On May 1 of that year, 14 more engineers were obligated at the University of Toronto. From that time to today most Canadian professional engineers have gone through that same ritual in their various camps, called Kipling camps—local chapters associated with various Canadian universities.
Henry Petroski, Duke University’s professor of civil engineering and history, notes in his book, “Forgive Design: Understanding Failure,” that Kipling’s poem “Sons of Martha” is often read as part of the ritual. However, sometimes inductees read Kipling’s “Hymn of Breaking Strain,” instead, which graphically depicts disastrous outcomes of engineering mistakes. The first stanza of that poem says:
The careful text-books measure
(Let all who build beware!)
The load, the shock, the pressure
Material can bear.
So, when the buckled girder
Lets down the grinding span,
'The blame of loss, or murder,
Is laid upon the man.
Not on the Stuff—the Man!
As if to strengthen the importance of these concepts, a persistent myth purports that the original iron rings were made from the beams or bolts of the Quebec Bridge that failed twice during construction. The bridge spans the St. Lawrence River upriver from Quebec City, and at the time of its construction was the world’s longest at 1,800 feet. Due to engineering errors and poor oversight, the bridge’s own weight exceeded its carrying capacity. Moreover, engineers downplayed danger when bridge beams began to warp under stress, saying that they were probably warped before they were installed. On August 29, 1907, the bridge collapsed, killing 75 of 86 workers. A second collapse occurred in 1916 when lifting equipment failed, and thirteen more workers died.
The ring myth, however, couldn’t be true. The original iron rings couldn’t have come from the failed bridge since it was made of steel, not wrought iron. Today the rings are made from stainless steel because iron deteriorates and stains engineers’ finger black.
On August 14, 2018, Morandi Bridge over Polcevera River in Genoa, Italy, collapsed from structural failure, killing 43 people.
Adobe Stock
The Seven Wardens decided to restrict the ritual to engineers trained in Canada. They copyrighted the obligation oath in Canada and the United States in 1935. Although the ritual is not a requirement for professional licensing, just like the Hippocratic Oath is not part of medical licensing, it remains a long-standing tradition.
The American Obligation of the Engineer has its own creation story, albeit a very different one. The American Order of the Engineer (OOE) was initiated in 1970, during the era of the anti-war protests, Apollo missions and the first Earth Day. On May 4, 1970, the National Guard shot into a crowd of protesters at Kent State University, killing four people. The two authors of the American obligation—Cleveland State University’s (CSU) engineering professor John Janssen and his wife Susan—reflected these historical events in the oath they wrote. Their version of the oath binds engineers to “practice integrity and fair dealing.” It also notes that their “skill carries with it the obligation to serve humanity by making the best use of the Earth’s precious wealth.” As Petroski explains in his book, “campus antiwar protestors around the country tended to view engineers as complicit in weapons proliferation [which] prompted some [CSU] engineering student leaders to look for a means of asserting some more positive values.”
Kip A. Wedel, associate professor of history and politics at Bethel College, wrote in his book, “The Obligation: A History of the Order of the Engineer,” that the ceremony was not a direct response to the Kent State shootings—it was already scheduled when the shootings happened. Yet, engineering students found the ceremony a positive action they could take in contrast to the overall turmoil. The first American ritual took place on June 4, 1970, at CSU. In total, 170 students, faculty members, and practicing engineers took the obligation. This established CSU as the first Link of the Order, as the OOE designates its local chapters. For their first ceremony, the CSU students fabricated smooth, unfaceted rings from stainless steel pipe. Later they were replaced by factory-made rings. According to Paula Ostaff, OOE’s Executive Director, about 20,000 eligible students and alumni obligate themselves yearly.
Societies hope that every engineer is imbued with a strong ethical sense and that their pledges are never far from mind. For some, the rings they wear serve a daily reminder that every paper they sign off on is touched by a physical reminder of their commitment.
These ethical and responsible engineering practices are especially salient today, when one in three American bridges needs repair or replacement, some have already collapsed, and engineers are working on projects related to the bipartisan infrastructure bill President Biden signed into law in 2021. Canada has committed $33 billion to its Investing in Canada Infrastructure Program. At the heart of these grand projects are many thousands of professional engineers, collectively working millions of hours. The professional vows they took aim to assure that the homes, bridges and airplanes they build will work as expected.
In the 1966 movie "Fantastic Voyage," actress Raquel Welch and her submarine were shrunk to the size of a cell in order to eliminate a blood clot in a scientist's brain. Now, 55 years later, the scenario is becoming closer to reality.
California-based startup Bionaut Labs has developed a nanobot about the size of a grain of rice that's designed to transport medication to the exact location in the body where it's needed. If you think about it, the conventional way to deliver medicine makes little sense: A painkiller affects the entire body instead of just the arm that's hurting, and chemotherapy is flushed through all the veins instead of precisely targeting the tumor.
"Chemotherapy is delivered systemically," Bionaut-founder and CEO Michael Shpigelmacher says. "Often only a small percentage arrives at the location where it is actually needed."
But what if it was possible to send a tiny robot through the body to attack a tumor or deliver a drug at exactly the right location?
Several startups and academic institutes worldwide are working to develop such a solution but Bionaut Labs seems the furthest along in advancing its invention. "You can think of the Bionaut as a tiny screw that moves through the veins as if steered by an invisible screwdriver until it arrives at the tumor," Shpigelmacher explains. Via Zoom, he shares the screen of an X-ray machine in his Culver City lab to demonstrate how the half-transparent, yellowish device winds its way along the spine in the body. The nanobot contains a tiny but powerful magnet. The "invisible screwdriver" is an external magnetic field that rotates that magnet inside the device and gets it to move and change directions.
The current model has a diameter of less than a millimeter. Shpigelmacher's engineers could build the miniature vehicle even smaller but the current size has the advantage of being big enough to see with bare eyes. It can also deliver more medicine than a tinier version. In the Zoom demonstration, the micorobot is injected into the spine, not unlike an epidural, and pulled along the spine through an outside magnet until the Bionaut reaches the brainstem. Depending which organ it needs to reach, it could be inserted elsewhere, for instance through a catheter.
"The hope is that we can develop a vehicle to transport medication deep into the body," says Max Planck scientist Tian Qiu.
Imagine moving a screw through a steak with a magnet — that's essentially how the device works. But of course, the Bionaut is considerably different from an ordinary screw: "At the right location, we give a magnetic signal, and it unloads its medicine package," Shpigelmacher says.
To start, Bionaut Labs wants to use its device to treat Parkinson's disease and brain stem gliomas, a type of cancer that largely affects children and teenagers. About 300 to 400 young people a year are diagnosed with this type of tumor. Radiation and brain surgery risk damaging sensitive brain tissue, and chemotherapy often doesn't work. Most children with these tumors live less than 18 months. A nanobot delivering targeted chemotherapy could be a gamechanger. "These patients really don't have any other hope," Shpigelmacher says.
Of course, the main challenge of the developing such a device is guaranteeing that it's safe. Because tissue is so sensitive, any mistake could risk disastrous results. In recent years, Bionaut has tested its technology in dozens of healthy sheep and pigs with no major adverse effects. Sheep make a good stand-in for humans because their brains and spines are similar to ours.
The Bionaut device is about the size of a grain of rice.
Bionaut Labs
"As the Bionaut moves through brain tissue, it creates a transient track that heals within a few weeks," Shpigelmacher says. The company is hoping to be the first to test a nanobot in humans. In December 2022, it announced that a recent round of funding drew $43.2 million, for a total of 63.2 million, enabling more research and, if all goes smoothly, human clinical trials by early next year.
Once the technique has been perfected, further applications could include addressing other kinds of brain disorders that are considered incurable now, such as Alzheimer's or Huntington's disease. "Microrobots could serve as a bridgehead, opening the gateway to the brain and facilitating precise access of deep brain structure – either to deliver medication, take cell samples or stimulate specific brain regions," Shpigelmacher says.
Robot-assisted hybrid surgery with artificial intelligence is already used in state-of-the-art surgery centers, and many medical experts believe that nanorobotics will be the instrument of the future. In 2016, three scientists were awarded the Nobel Prize in Chemistry for their development of "the world's smallest machines," nano "elevators" and minuscule motors. Since then, the scientific experiments have progressed to the point where applicable devices are moving closer to actually being implemented.
Bionaut's technology was initially developed by a research team lead by Peer Fischer, head of the independent Micro Nano and Molecular Systems Lab at the Max Planck Institute for Intelligent Systems in Stuttgart, Germany. Fischer is considered a pioneer in the research of nano systems, which he began at Harvard University more than a decade ago. He and his team are advising Bionaut Labs and have licensed their technology to the company.
"The hope is that we can develop a vehicle to transport medication deep into the body," says Max Planck scientist Tian Qiu, who leads the cooperation with Bionaut Labs. He agrees with Shpigelmacher that the Bionaut's size is perfect for transporting medication loads and is researching potential applications for even smaller nanorobots, especially in the eye, where the tissue is extremely sensitive. "Nanorobots can sneak through very fine tissue without causing damage."
In "Fantastic Voyage," Raquel Welch's adventures inside the body of a dissident scientist let her swim through his veins into his brain, but her shrunken miniature submarine is attacked by antibodies; she has to flee through the nerves into the scientist's eye where she escapes into freedom on a tear drop. In reality, the exit in the lab is much more mundane. The Bionaut simply leaves the body through the same port where it entered. But apart from the dramatization, the "Fantastic Voyage" was almost prophetic, or, as Shpigelmacher says, "Science fiction becomes science reality."
This article was first published by Leaps.org on April 12, 2021.