[Editor’s Note: This piece about how astronauts stay healthy in space comes to us from Paisley Hansen. Hansen is a freelance writer and expert in health, fitness, beauty, and fashion. When she isn’t writing she can usually be found reading a good book or hitting the gym.]
In 1962, John Glenn sucked pasty, dehydrated applesauce out of an aluminum tube and became the first person to ever eat in space. Fast forward to 2020, and eating in space looks a whole lot different than it did on the Mercury mission in 1962.
Today, the meals astronauts eat in space, such as spaghetti and scrambled eggs, mimic the ones they could eat at their kitchen table—only they are freeze dried and packaged into lightweight pouches. While the modern terrestrial dining experience has transformed to include kitchens, hot water, and creative meals, scientists are still working to increase the shelf life and nutrient density of space travel meal plans.
Gravity: The Fundamental Problem for Food Scientists
Consider all the forks, knives, plates, and other traditional dining items that you rely on to eat a meal and imagine them flying around your kitchen. Herein lies the fundamental problem of eating food in space—gravity. In space, food—and all associated kitchen objects—float. If you let go of a package of ketchup, it will drift off and fly around your spaceship. If you try to pour a glass of water, the water and the cup will float in the air. This makes creating meals and their packaging the fundamental problem of food scientists. In addition, there are no refrigerators or freezers at the space station to preserve food, making it challenging to provide astronauts with adequate nutrients, such as protein isolate. However, food scientists have developed creative preservation methods to increase the nutrition and taste of space meals.
Freeze-Dried Food Preservation
Freeze-drying preserves food by removing water. The large majority of food has a very high water content—80 to 90%—that allows bacteria and other microorganisms to thrive. When foods retain their water content, organisms can feed on the food matter, cause chemical reactions, and prematurely spoil a food product. Removing water from food allows it to stay good for a long period of time.
Another key advantage of freeze-drying for space travel is that it reduces the weight of food. One of the fundamental strategies of planning meals for space travel is choosing lightweight options. Freeze-drying allows food scientists to incorporate key nutrients and yummy foods into a space travel meal plan.
Once in space, astronauts can eat freeze-dried foods by using a water gun to add hot water to the pouches. Once the food absorbs the water, it is ready to eat.
Thermo-stabilization is another process food scientists harness to preserve foods and meals that would traditionally spoil in a short amount of time. Thermo-stabilized food involves using high temperatures and pressure to destroy bacteria, microorganisms and enzymes that could cause food to spoil. The heat processed food is then packaged into pouches—rather than traditional cans—to reduce overall weight for space travel.
Thermo-stabilized food is unique in that, unlike other food preservation methods for space travel, it doesn’t require rehydration—astronauts can simply open the pouch and eat the meals immediately.
The Future: Nutrition and Safety for Longer Missions
The nutrition of space meals has come a long way. Early space missions used military meal plans that were high in fat and salt and lacked adequate nutrition. Today, food scientists harness preservation methods to ensure astronauts obtain the macro and micro nutrients that compose a healthy diet. A contemporary astronaut might enjoy a three course meal of roast beef, carrots, and mashed potatoes.
Even with the significant advancements in the space food system, food scientists have not figured out a way to ensure proper nutrition for crews that might go on longer missions, such as to Mars or further. A long duration mission to Mars would need meals to have a shelf-life of 3 to 5 years. Creating a terrestrial food system that will meet the nutrition and food safety standards of long missions will require a lot of innovation.
Tubes of pasty apple sauce are a distant memory for the space food system—innovations in food preservation have allowed meals in space to look a lot like meals at home. As food scientists look to the future, they will have to create new innovations for longer space missions.