Any kid who has taken a trip to a science museum has tried astronaut ice cream, the dehydrated treat that astronauts take up into space—where real frozen treats wouldn’t make it. But as we plan for longer space missions, isn’t there something more that we can provide our intrepid space explorers? The solution mirrors science fiction: Star Trek featured replicators able to summon any desired food out of thin air. A scientist has proposed creating the same thing for our real-life astronauts: a 3-D printer that can make pizza (or anything else) in space, far away from fresh ingredients.
Earlier this month, Quartz broke the news that Systems & Materials Research Corporation received a $125,000 grant to spend six months building a prototype of a 3-D food printer—one that will be able to print out a tasty pizza before venturing on to other food items. I spoke to NASA to find out more about its interest in the technology.
The pizza printer is the brainchild of Anjan Contractor, a mechanical engineer at Systems & Materials who has long worked on 3-D printing technologies. According to his NASA proposal, the printer spits out starches, proteins, fats, texture, and structure, while the inkjet sprays on flavor, smell, and micronutrients.
He tells Quartz:
It works by first "printing" a layer of dough, which is baked at the same time it’s printed, by a heated plate at the bottom of the printer. Then it lays down a tomato base, "which is also stored in a powdered form, and then mixed with water and oil," says Contractor.
Finally, the pizza is topped with the delicious-sounding "protein layer," which could come from any source, including animals, milk or plants.
You’re probably familiar with the kinds of foods that astronauts have access to today—it’s not all that different from the aforementioned "space ice cream" found in science museums the world over. All foods provided to astronauts are freeze dried or thermostabilized (like canned foods). They’re also prepackaged so that they can be eaten in microgravity, where things tend to fly around if they aren’t contained. The options are virtually unlimited, as long as the foods can be stored at room temperature (there aren’t enough resources for refrigeration and freezing). Beef brisket and shrimp cocktails are reportedly popular options.
Astronauts get supplies when necessary from the International Space Station, where cargo vehicles transport their "fresh" food. But future astronauts who go to more distant places, like Mars, won’t be able to resupply. That’s where NASA’s Advanced Food Technology Project comes in—and potentially, where 3-D printed foods will help out in the future.
Food on long-haul space flights needs to meet a slew of requirements. It needs to have a five-year shelf life, perhaps most importantly. But there are other issues it needs to address. "This is the only food that the crew members will have, so it needs to maintain its nutrition content for the length of the mission, and it has to be acceptable. If they don’t want to eat it, they won’t eat enough," explains Grace Douglas, an Advanced Food Technology Project Scientist at NASA.
3-D printed food is one of a handful of options that NASA is looking at. "3-D food printers are looking at providing powdered forms of ingredients, and these would not be processed ahead," says Douglas. That’s a good thing: minimally processed food has more nutrients, and it’s tastier. It also allows for even more options than what’s available today. Pizza is one of the comfort foods unavailable to astronauts on current missions; Contractor’s 3-D food printer could change that. And since the 3-D printer does most of the work, astronauts wouldn’t have to deal with extensive food prep.
There’s one big hitch, though: 3-D printing probably wouldn’t work so well in microgravity (remember: things fly around). It would likely be more useful in surface missions, where gravity isn’t as much of an issue.
NASA is also exploring other processing technologies outside of the 3-D printing realm. High-pressure processing, which uses high pressures with a low-heat treatment to sterilize foods, is one option. Another is microwave sterilization—a process that uses high-heat treatments for a shorter period of time. "The issue with those two processes is that we use high-barrier packaging, and it’s not compatible. Even if you end up with higher-quality food, we don’t have packaging that will keep that higher quality," explains Douglas.
In any case, all three of the aforementioned technologies are in the very early stages of development. But, Douglas notes, "by the time we end up going to Mars, a lot of these could be used commercially at that point."
Contractor has visions of his 3-D food printer being used on Earth, too. He writes in his NASA proposal:
With the anticipated world population of 12 Billion by the end of the century, the current infrastructure of food production and supply will not be able to meet the demand of such a large population. The conventional technologies can only provide marginal efficiency, which is not enough in keeping food prices at affordable level for the population growth. By exploring and implementing technologies such as 3-D printing, this may avoid food shortage, inflation, starvation, famine and even food wars. In addition, US military can use 3-D printed food system during many of their missions.
Powdered food is rarely as tasty as fresh fruits, vegetables, and meats, but food production shortages change what people are willing to tolerate. Before we can even think what a future of 3-D printed food will look like, Contractor needs to turn his dream into a fully formed product—and that will take awhile. His NASA proposal was only accepted for a phase I feasibility study, and if that works out, there will be more studies ahead. "When you’re looking at these things at a preliminary level, it could be years until it becomes feasible," says Douglas.