In Space, There Are No Drive-Thrus
By Jon Sung
Imagine you're going camping for a week. It’s way out in the middle of nowhere, so you're going to need to carry all your food with you. Also, when it’s dinnertime, you can't use fire. Why? Maybe it's wildfire season, or your camping buddies are really into post-apocalyptic survival scenarios and don’t want risk attracting bands of marauding mutants with a visible campfire. Whatever the reason, an open flame is off the table—so no roasting marshmallows or hotdogs on a stick. How much are you looking forward to your excursion in light of this new information?
Now, imagine that weeklong camping trip lasts a bit longer—two to three years longer.
That's about how long it'll take to send people to Mars and back, assuming you want them to do some useful science once they get there and then return reasonably to Earth healthy. All other questions regarding such a mission aside (How will astronauts survive the hard radiation of interplanetary space? What about the psychological rigors of the long journey? How are they going to get off the surface of Mars to return home?), one of the big ones we need to answer is, “What are they going to eat?”
Well, teams could pack it up and bring it all with them, right? True, but consider this: they can't bring traditional canned foods. Every ounce of weight counts when you're trying to boost something into orbit—$1 million per pound is a reasonable ballpark figure for the cost of sending items to Mars—which pretty much rules out your standard tin can. NASA's been using plastic vacuum bags, which have the added bonus of being easy to pump hot water into (think of Cup Noodles without the cup). But no matter which way you store it, the challenge is still incredible: the food has to stay good for years and still be appetizing come mealtime. Think about how long food lasts in your refrigerator and shudder. That’s why when you look over NASA’s mission menus, you see words like “rehydratable,” “irradiated” and “thermostabilzed.”
And there's going to be an insane amount of food needed for a mission to Mars—around 22,000 pounds or more. At $1 million a pound, you don’t need a calculator to figure out it’s going to be very, very expensive.
What if you could somehow grow your own food, reducing what you need to pack? Three volunteers at the Beijing University of Aeronautics and Astronautics underwent a three-month mock mission in a sealed biosphere surviving on farmed plants and mealworms: they grew vegetables, ate them, and fed the leftovers to the mealworms, which they also ate. This seems like a better strategy, but it's without problems. Assuming you can get past the “yuck” factor of eating insects, mealworms aren't a self-sustaining food supply. In order to make more mealworms, you have to let some of them mature into beetles, which then lay eggs and so forth. But beetles aren't particularly good to eat. And where would you put the farm? Finding room in a spaceship will be a challenge; there's the weight problem again—we don't pack astronauts into claustrophobic, tech-packed capsules for fun, we do it to save on launch costs.
And finally, what happens if the mealworms get out, or the farm breaks and dirt goes flying around the spacecraft? On Earth, you’d just get a broom. In a microgravity environment, you’d inhale it, or it’d get into the ductwork and circuitry (or somewhere else equally disastrous).
At some point, the topic of algae always comes up. Why don't we just raise algae in space and chow down on that? Spirulina's good for you, right? Perhaps surprisingly, there are still many questions about algae-based space food nobody's put a lot of work into solving just yet—among them the issue of growing algae in the aforementioned hard radiation environment of interplanetary space, as well as how to make the result even vaguely palatable.
So until someone in food science makes a radical breakthrough, work will continue on perfecting such dishes as pouch-based, freeze-dried shrimp cocktails—which, in the opinion of famed astrophysicist Dr. Neil deGrasse Tyson—are surprisingly good. Bon appetit!
Jon Sung is a contributing writer for XPRIZE and copywriting gun-for-hire to startups and ventures all over the San Francisco Bay area. When not wrangling words for business or pleasure, he serves as the captain of the USS Loma Prieta, the hardest-partying Star Trek fan club in San Francisco.