Preventing Scurvy And Piling On The Calories: How To Feed Astronauts In Space

As with any long-haul expedition, astronauts exploring the wilderness amongst the stars need to pack their food with great care. Food needs to last for long periods of time without spoiling and to provide astronauts with sufficient nutrition to meet space’s unique demands.

Astronauts on early space missions such as the Apollo and Gemini programs consumed their foods like pastes from aluminum tubes. Now, astronauts can indulge in international cuisine heated in microwaves and convection ovens. About five months before a spaceflight, astronauts choose exactly what type of foods they’ll eat during their missions. A 30-day flight menu is created, offering an inviting selection of foods that are all stored in the galley onboard by the crew members.

Citizen astronaut, aquanaut and physician Dr. Shawn Pandya explained what goes into filling up the space kitchen.

"NASA and other space agencies have invested significant time and money to create a diverse, palatable menu. For example, in 2005, celebrity chef Emeril Lagasse was enlisted to adapt some of his recipes for space, which included jambalaya, mashed potatoes, green beans with garlic, rice pudding and more. Other common menu items include eggs, bacon, toast, macaroni and cheese, turkey and asparagus."

In November 2020, astronauts on the ISS celebrated Thanksgiving together by preparing a meal that consisted of cornbread dressing, curry and rice, and smoked turkey.

The main aim is to provide food that has sufficient nutrients to prevent scurvy, a Vitamin-C deficiency caused by a lack of fresh fruits and vegetables, which can cause serious health issues such as anemia, exhaustion, spontaneous bleeding, limb pain, swelling, ulceration of the gums and loss of teeth. Scurvy was common amongst sailors until the mid 19th century—so common and so deadly that a 50 percent death rate was assumed for those who contracted scurvy.

"Nutrition considerations in space are multifactorial, and the research around space nutrition is constantly evolving. Basically, food on the ISS has to meet the daily caloric intake requirement of an astronaut, be palatable (remember, taste is blunted in space due to sinus congestion from fluid shift), have a long shelf-life, easy to prepare, non-crumbly (imagine crumbs in [zero gravity]), diverse (current menu estimates of ISS food items [is] around 220), and also fit the very tight operational schedule of the astronauts,” Dr. Panyda says.

“We know that bone health is impacted by increased bone breakdown, and that there are studies that suggest that there is decreased calcium absorption from the gastrointestinal system in space. As such, Vitamin-D and calcium supplementation make sense.

“We also need to pay attention to micronutrients such as zinc and selenium and how they are absorbed and metabolized in space. I have seen another report that Vitamin C recommended daily intake is increased in space. Finally, there are suggestions that vitamin B12 and folate absorption are implicated in the Space Adaptation Neuro-ocular Syndrome. So there is a lot to consider when it comes to making the 'perfect menu' for space!"

Astronauts can monitor their intake of calories—which needs to be much higher in space—by scanning a barcode on a meal or foodstuff. Depending on the source and individual characteristics of gender, age and activity level, caloric intake typically ranges between 1,900–3,200 for a small woman and 2,700–3,700 calories a day for a large man.

As for water on the ISS, waste water like urine is boiled and then turned into potable water through a redesigned urine distillation process. There is a water station where astronauts use a water gun to reconstitute dehydrated meals and fill up the water bags from which they drink. In 2014, the Italian Space Agency sent up the first espresso machine in space, ISSpresso, which was specially designed to operate in the microgravity environment.

Drink options include water, freeze-dried tea and coffee, and drink mixes for orange juice and lemonade in a vacuum-sealed pouch. According to Dr. Pandya, food is a huge morale booster individually and facilitates team bonding over a shared meal. The menu also reflects the cultural diversity of the crew aboard the ISS.

Due to the relative lack of fresh fruit and vegetables available to astronauts in space, ensuring a balance of important nutrients is vital, as chemical imbalances can cause several psychological and physical issues.

Dr. Pandya expands: "Space and microgravity environment carry significant impacts for nearly every physiological system, from bone health to immunology, and the in-flight menu needs to be optimized to mitigate deleterious effects, and even provide countermeasures. Increased calcium and Vitamin D content to optimize bone health are two such examples. Isolation and confinement and the psychological stresses that come with it are a very real consideration of the spaceflight environment."

Astronauts on the ISS have delivered valuable data on how nutrition affects their physiology, including how much their diets mitigate against the loss of bone density in space and how best to treat it. Data gained from astronauts also offer insights into cell and bacterial behaviour, innovative techniques for healing wounds, and for understanding psychological stress-response systems.

One of the ways to manage nutritional needs and medical care for astronauts is by preventing it during the selection process. Dr. Pandya explains, "Space agency astronauts, such as NASA, ESA and CSA astronauts, are stringently screened for both 'select in' and 'select out' criteria, both physically and psychologically. So for example, a history of kidney stones or psychosis both constitute 'select out' criteria.”

Dr. Pandya notes that changes in the environment during spaceflight can predispose astronauts to kidney stones, so anyone who is prone to stones on earth anyway will be screened out of a mission.

“Spaceflight is risky and expensive, therefore anything we can do to mitigate risk, we do.”

Medical attention continues throughout all aspects of the mission, with measures before, during, and after the flight to monitor astronauts and rehabilitate any injuries and ailments.

“For example, we know that astronauts experience bone and muscle mass loss due to the microgravity environment. As such, astronauts undergo approximately two hours of aerobic and resistive exercise while on-station, six days a week, to mitigate these changes. The rehab continues post-flight as well. Astronauts are continually monitored, and also undergo regularly scheduled meetings with the flight surgeon, psychologist, and family to maintain their health; they are even put into pre-flight quarantine for several weeks to ensure no infectious diseases come with them to the ISS! There are also on-board medical kits and medications to deal with medical issues such as bladder infection, trauma, headache, etc. If worst comes to worst, there are also capabilities for crew medevac."

Nutrition and medical care needs will have to evolve for exploration-class missions and longer missions to the Moon and Mars in the coming years.

"The shelf-life of foods will need to increase to several years for Martian missions, and we will need to work on manufacturing food in-situ due to the challenges of resupply from Earth."

Space-food companies such as Mission: Space Food, a health and technology company focusing on space nutrition, have started to tackle this problem. Mission: Space Food uses an integrative approach to human health, with a focus that begins with the brain. The company’s team of Michelin Star chefs, cognitive nutritionists, and aerospace engineers combine space science with experiential design.

This began with their first product, ASTREAS, which is a highly nutritious truffle composed of 13 vitamins and 9 minerals, “designed to fill the micronutrient gap” in one bite. Such foods could provide the answer to the long-term needs of astronauts on longer space missions.

The way astronauts cater for their nutrition is changing and with commercial space travel fast approaching, space food and nutrition in space have to improve fast. Explorers, astronauts, cosmonauts and tourists are counting on it.