For 20 seconds this past April, Apollo Arquiza and Bryan Caldwell got to experience the joy of cooking on Mars.
On the menu was fried tofu and hash browns, and it was the very first time on record people have attempted to cook in low-gravity.
Arquiza is definitely no Julia Child—he and Caldwell are researchers involved with a Cornell University program that is studying how we’ll feed the first astronauts that travel to Mars, a mission that NASA expects could take place by the 2030s, as well as how we'll sustain longer visits.
"If we’re ever going to stay for a long time on the moon or on Mars, there’s going to be some kind of cooking involved," Arquiza said at a talk in New York City yesterday.
In the future, Mars colonists may grow fresh produce that they can cook. But before that happens, early Mars astronauts may want to try to cook themselves hot meals from the shelf-stable or freeze-dried ingredients that they bring on their trip. Experts believe that eating the "just-add-water" pre-packaged meals that astronauts on the International Space Station consume today could be hard on their bodies and minds over the course of such a long mission (it will take six months just to reach Mars).
To attempt cooking in low-gravity, NASA’s Reduced Gravity Program gave the team time aboard a G-Force 1 space simulator, which is a plane that flies up and down like a roller coaster to simulate different gravity situations.
After convincing the crew that they wouldn’t burn up the plane, the Cornell team was allowed to load the prototype space fryer they’d developed back at the lab on board.
There’s a lot to consider when designing a cooking contraption for low gravity, especially one to be used in an enclosed environment (Truly zero-gravity cooking, by the way, is basically not possible unless you re-create gravity by spinning the cooking apparatus). There are smells to consider, and the water vapor or particles that might build up. It’ll take longer for water to boil and cook, because with less gravity, heat convection could be slower.
And then there are those oil droplets to think about.
"We thought about what would be the most stressful cooking thing that could be done—and that’s stir frying," says Arquiza. "If we could sort of find the solution for that, then the others would not be that bad."
To begin to design a fryer for Mars, where the gravity is only a third as that on Earth, the researchers’ main goal right now is to understand how exactly the oil will splatter. "Is there a mathematical model that will describe the splattering?" Arquiza asks. "Once you have your model, you can conceptualize whatever design you want and run it through your model."
They needed data. They started on Earth first—dying cooking oils red, and placing white paper all around the gas range as they cooked tofu and hash browns. With splattered red drops all over the paper, the images of the results look like a crime scene out of Law and Order. From these, it was easy to use software to count the droplets and measure their size and distance traveled.
Later, with the frying pan and paper bolted down inside a cooking hood on the space simulator, they repeated the same experiments. On each of many flights completed over four days, the researchers had 20 seconds to cook under both Mars (1/3 Earth gravity) and moon (1/6 Earth gravity) conditions.
Arquiza is still analyzing the data and building his model, but he can say with assurance that oil droplets do travel more, are bigger, and are more numerous under low-gravity. Some day, he’s pretty confident he could overcome the challenges of designing a fryer for Mars. Actually doing so—that will require another research grant, he says.
Simulating Weightlessness, Volunteer "Pillownauts" Stay In Bed For 70 Days
Food is clearly only one of the major challenges associated with sending humans to Mars, but it is an important one. It’s well known that "food boredom" on long, isolated journeys can cause a person to eat fewer calories and become malnourished. This is one reason Slim-Fast diets work. It happens with astronauts on the International Space Station today.
The frying experiment was only one small part of a larger research program on the social and logistical aspects of food in space, run out of the lab of Jean Hunter, an associate professor in Cornell’s biological and environmental engineering department.
In 2013, she ran a simulated Mars mission to Mars to test how future astronauts would feel about their food on a long mission. Six volunteers lived in isolation in a geodesic dome on a desolate Hawaii lava slope for four months, cooking meals like "Cajun Style Spam Jambalaya" and "Oatmeal Thickened Beef Stew" from a pantry stocked with limited space-friendly ingredients. One goal was to measure how much menu fatigue would set in.
An even crazier experiment took place this past year. Caldwell, who also works in Hunter’s lab, recruited 16 volunteers to report to NASA’s Flight Analog Research Unit in Galveston, Texas. Paid $10 an hour for each waking hour, these "pillownauts" lay in bed without getting up for 70 days, their feet slightly elevated above their heads, bed pans by their side. This setup simulates how, in zero-gravity, such as aboard the International Space Station or on the journey to Mars, an astronaut’s fluids move to the upper body, causing the nose to become congested and face to swell. Half of the pillownauts were allowed to exercise. Since they weren’t allowed to get up, this involved a harness that elevated them off of their gurney, and a vertical treadmill and stationary bike affixed to the wall. Easy enough—now, they could run and bike up the wall.
The goal of this elaborate setup was, again, to measure how the subjects responded to food and the physiological changes in their ability to smell and taste.
"The problem that we’re finding in space is that we need our astronauts to eat well," says Caldwell. "They need adequate nutrition, and they’re not." While NASA has a huge variety of prepackaged foods available that astronauts can choose from, they can’t mix ingredients or get creative. "The astronauts, even though they have all this variety, are still complaining that their food tastes bland in space," says Caldwell.
In the bed rest experiment, the researchers measured the subjects’ nasal congestion and air flow, their ability to identify food smells, and their excitement levels about their repetitive meals. All in all, they’re finding mixed results—but the subjects' food excitement for many of the meals did decrease over the course of 70 days. After six months, things could look, and taste, pretty bleak.
The researchers have plenty of time to address these challenges, but they may need it. Says Caldwell: "A mission to Mars is going to challenge our food technologies. It’s a long, long trip."