What do astronauts eat in space? What food requirements must be met on Earth in order to be allowed to space flights? These and other questions were answered.
After the holidays, interest in diets usually increases. Losing weight is on many people’s “new year’s resolutions” list. We usually want to lose weight as easily as we gained it. On the Internet, it is easy to stumble upon publications about the space diet or the diet of astronauts, promising a miraculous result – minus 20 kg in 20 days. Most of these published “space diets” on tabloid websites are complete nonsense, in fact.
What exactly is the astronauts’ diet? Should they eat the same menu repeatedly, every single day? What food requirements must be met on Earth in order to be allowed to space flights? These and other questions were answered by the doctor of the Russian crew members of the International Space Station Alexander Vasin and the cosmonaut of Roscosmos Ivan Wagner.
Can astronauts even swallow in space?
Fun fact: in the early years of space exploration, nobody really knew if an astronaut could swallow in space or not. In 1962, American astronaut John Glenn (July 18, 1921 – December 8, 2016) proved that astronauts can eat in space (in a microgravity environment). Glenn was the third American in space, and the first American to orbit the Earth, circling it three times in 1962.
What do astronauts eat? The interview
As follows from the interview, the so-called “space diet” advertised on the Internet has nothing to do with astronauts. The best way to keep your weight at the desired level is not to overeat on weekdays or holidays! Eat a balanced diet and take care of your health!
- Ivan, do you know anything about the space diet?
- I. Wagner: I hear it for the first time.
- A. Vasin: And I, as a doctor, am not familiar with such a concept.
- Preparation for a space flight begins approximately one and a half to two years before it. Surely from this moment on, the diet of the astronauts included in the crew is changing?
- I. Wagner: There was nothing unusual in our menu, we eat like most people, without any restrictions.
- Alexander, is it really true, without restrictions?
- A. Vasin: There are no restrictions, but the first requirement is to eat in the flight canteen of the Cosmonaut Training Center, which has the necessary assortment of products and ensures high quality of their preparation. Another requirement of doctors is that meals should be regular: breakfast, lunch, and dinner at the same time. You can shift breakfast by half an hour or by an hour if some experiment requires fasting blood sampling.
- Ivan, is the food tasty in the flight canteen?
- I. Wagner: Yes. I can’t even single out a dish, I like almost everything.
- A. Vasin: The canteen employees know the cosmonauts’ preferences and try to take them into account. Someone cook a casserole for breakfast, some scrambled eggs. There is a very friendly atmosphere, supportive, calm. Cosmonauts feel peace of mind – this is very important.
- Can they ask for a supplement?
- A. Vasin: They can, but they try to control their weight and not overeat. There is a specific instruction for medical examination, which indicates what the maximum weight of an astronaut can be in relation to his height. If you regularly eat in the flight canteen, there will be no problems with excess weight. There are a lot of salads, fruits on the menu, and in general, the food is balanced and varied.
- Is it more difficult to control your weight in space?
- A. Vasin: There is a device that measures body weight in zero gravity. During the flight, the astronauts are weighed once a month. If someone loses weight or, conversely, gains weight, doctors begin to worry. It is considered normal when the astronaut’s weight does not change during the entire flight.
- It turns out that food in tubes does not lead to weight fluctuations?
- I. Wagner: Now in tubes there are only tomato and apple-cranberry sauces. The rest is freeze-dried and canned food, while they try to do everything without any harmful additives. For example, we prepared the borscht in the usual way, then the moisture was removed from there and placed in a vacuum bag. It has a neck in the form of a “dovetail” through which we pour warm water in orbit, and the product becomes edible. Cut off the top of the bag and eat it with a long spoon from our personal set. We just heat the canned food – there is special food warmer on the dining table.
- A. Vasin: An important point is that food should be enjoyable: it should smell, taste, and look like homemade food. We strive for this. There is also an important requirement for products – so that they do not crumble, crumble, and stick to the spoon. When opening the jar, be sure to wrap it with a towel, because the hot liquid can escape from there and stain the panels.
- I. Wagner: And this happens sometimes. It seems that you are trying to do everything neatly, and all the same, the spray scatters. The panels had to be washed several times.
- Is it true that taste preferences change in zero gravity?
- I. Wagner: I would not say that they are changing. You just want more spicy and sour ones, because there are not enough taste stimuli. We have a regular diet for 16 days. Each day has its own menu, and then everything is repeated in the same order.
- A. Vasin: During the pre-flight preparation, the food products supplied to the ISS are tasted. The astronauts taste each product and give it a rating on a 9-point scale. Some of the products can then be replaced, and, in addition, there are bonus containers. For example, astronauts can order a whole container of cottage cheese with black currant, sea buckthorn, or nuts.
- I. Wagner: We can replace dishes from the pants menu with products from bonus containers in order to somehow diversify it.
- A. Vasin: The tasting also applies to drinks. The astronaut chooses tea, for example, with bergamot, or coffee, according to his preferences: with sugar, milk, or without them. A tea bag is placed in a vacuum package or coffee is poured, which is then poured with hot water. There is no household refrigerator at the station. If the astronauts want something cold, they place a bag of drinks on the fan to cool it down.
- I. Wagner: American astronaut Chris Cassidy really liked our coffee with milk and sugar. He even had a sign: if you manage to “drink” it in the morning, then the day will pass well. I happily gave Chris coffee bags. Our fellow astronauts also willingly treated us to their products. They had Mexican and Italian dishes on the menu.
- Did you miss earthly food?
- I. Wagner: Of course we missed you. After a month or two, freeze-dried and canned foods begin to get boring.
- A. Vasin: Vegetables and fruits are delivered to the ISS by trucks – 2 kg per astronaut in one package. During their stay on the ISS, the crew can receive such a package once or twice.
- I. Wagner: We got oranges and apples. Both I and the commander of our crew, Anatoly Ivanishin, ate grapefruit very willingly. A Japanese truck brought Chris Cassidy kiwi – ripe, sweet, delicious! If the crew is to celebrate the New Year onboard or celebrate some other holiday, they try to save the fruits for the festive table. For example, my relatives gave me a cake as a gift. True, the Progress MS ship delivered it two weeks after my birthday, so we treated ourselves to something else. As the Dragon crew were leaving, they had a quick festive snack. Before the astronauts left for the ship, I brought a cake and we ate it goodbye.
- Can the table be served beautifully in zero gravity?
- I. Wagner: In zero gravity, you can only stain the walls beautifully (smiles). To prevent the products from flying away, we fasten them with special clothespins to the walls or use adhesive tape. We stick it on the table with the sticky side up and cling to our cans and products.
- Who usually sets the table and receives guests: astronauts or cosmonauts?
- I. Wagner: It depends on whose holiday. Where you can gather at a common table, there is equally little space on both the Russian and American segments of the station. Imagine an ordinary kitchen, 10-12 square meters, in this kitchen you eat, run, sleep, work, pedal on a bicycle. A bit cramped, but two crews (6 people) fit both in the astronauts’ kitchen and in ours.
- A. Vasin: Moreover, someone can take a seat on the floor, someone on the ceiling.
- I. Wagner: You can sit on the wall too. The main thing is to fix yourself so as not to fly away. What is upside down, what is up, there is absolutely no difference for a feast in zero gravity.
- Do you drink or eat during landing?
- I. Wagner: No, because it is really hard to do. We have supper before closing the hatches, then drink water with salt additives in the spacecraft. We have water with us, but during the descent, we did not drink it.
- How long does the descent take?
- I. Wagner: We closed the hatches at 23.30, and at about 6 am there was a landing: you can live without water and without food for six and a half hours. In addition, the work is intense during the descent, you don’t think about anything else.
- Alexander, was it in your memory that one of the cosmonauts asked for food or drink immediately after the landing?
- A. Vasin: I brew herbal tea in a thermos and give it to the astronauts in small sips at the landing site. After leaving the crew of the descent vehicle, we try to place it in the tent as soon as possible so that there is less contact with people around. We must not forget that the planting takes place in the steppe, where there are dirt and dust.
- But, in the photos, sometimes you can see the landed astronauts and cosmonauts with an apple or some other fruit in their hands.
- A. Vasin: Astronauts usually want to hold something earthly in their hand, and smell it. And the apple that they are given, of course, is disinfected. But the doctor always whispers in the astronaut’s ear: “Please, I ask, do not eat!”
- A. Vasin: Because the hands are dirty, and the immunity of the astronauts is weakened after spending months in space. They get a set of food from the flight canteen on the plane on their way home, and even then they can have a snack.
What do astronauts eat? A historic summary of “space diet”
Here’s the great article published by NASA titled “Space Station 20th: Food on ISS” by John Uri (NASA Johnson Space Center).
The first space missions
On April 12, 1961, Soviet cosmonaut Yuri A. Gagarin made history as the first human in space aboard his Vostok capsule. During his single orbit around the Earth, he also became the first person to eat in space, squeezing beef and liver paste from an aluminum tube into his mouth. For dessert he had a chocolate sauce, eating it using the same method.
His fellow cosmonauts who flew longer missions, up to five days, also consumed their meals from tubes. Astronaut John H. Glenn was the first American to eat in space – apple sauce from a toothpaste-like tube. His fellow Mercury astronauts on slightly longer missions consumed other food items also from tubes. These early experiences proved that humans could eat and swallow in weightlessness with no ill effects, although the meals weren’t particularly appetizing.
Gemini – Apollo era
Freeze-dried foods were introduced during the Gemini Program to support astronauts for missions lasting up to two weeks. Crewmembers used the spacecraft’s water supply to reconstitute the food prior to eating.
During Apollo missions to the Moon, astronauts had about 70 items to choose from, including entrees, condiments, and beverages. The food came freeze-dried and prepackaged, requiring the astronauts to add water from the onboard supply.
Some improvements were made in the course of the Apollo program, including the addition of hot water to rehydrate some food items and food that could be eaten out of its bag using a spoon. Sandwiches were tried but proved less than ideal, as the bread didn’t stay very fresh and caused crumbs that would float away in the cabin and possibly cause harm to sensitive equipment or even get in the astronaut’s eyes or lungs.
The number of items aboard Skylab didn’t increase very much, but the preservation of some foods did, made possible by the addition of a freezer aboard America’s first space station. According to Charles Bourland who developed much of the food system for Skylab, about 15 percent of the food supply was frozen and the astronauts could enjoy lobster Newburg, ice cream, and other frozen delicacies. The remainder of the food items were stored in cans which provided a long shelf-life.
Apollo-Soyuz Test Project (ASTP)
During the Apollo-Soyuz Test Project (ASTP) in 1975, American astronauts sampled Russian space food for the first time as crewmembers shared meals during two days of docked activities. Much of the food aboard the Soviet Soyuz came in tubes, and Soviet Commander Aleksei A. Leonov played a prank on American astronauts Thomas P. Stafford and Donald K. “Deke” Slayton by replacing the labels on tubes of borsch with labels from famous Russian vodkas.
Space Shuttle and MIR Space Station
With the advent of the Space Shuttle in 1981, the availability of a galley to both rehydrate and reheat foods made the astronauts’ menus more palatable and varied. The lack of refrigeration on the other hand required most food items to be dehydrated or thermostabilized, apart from a small locker of fresh food intended for immediate consumption.
The space station Mir’s Core Module included a dining table with the ability to reheat food in cans and tubes, and using a nearby cold and hot water dispenser, cosmonauts could rehydrate certain food items such as juices and soups.
Over the course of its 15-year lifetime, a steady stream of uncrewed Progress cargo resupply vehicles brought food to the station, including much welcome fresh fruits and vegetables. The variety of Russian dishes was regularly supplemented when visiting crewmembers from other nations brought their own culinary specialties. The first French citizen to visit Mir, astronaut Jean-Loup Chrétien, brought such items as paté, sautéed veal, cheeses, and chocolate.
During the Shuttle-Mir Program, American astronauts residing aboard Mir first ate mostly Russian food, but on later missions brought American food as well, such as astronaut Shannon M. Lucid’s favorite, jello, that became a regular Sunday treat with her Mir 21 crewmates Yuri I. Onufriyenko and Yuri V. Usachev. Andrew S. Thomas remarked very positively on the variety and quality of the Russian food during his five-month stay aboard Mir in 1998, especially praising the Russian soups and fruit juices.
One item noticeably absent from these past space menus is bread. As noted above, attempts at flying sandwiches during Apollo missions met with little success. In November 1985, Mexican Payload Specialist Rodolfo Neri Vela, who was a crewmember aboard Atlantis during the STS-61B mission, requested that tortillas be included in his food supply
Once in orbit, his fellow crewmembers noticed that the tortillas, unlike regular bread, didn’t create crumbs and could be used to make sandwiches or hold other food items. Since that mission, tortillas have been a favorite of astronauts and are standard fare aboard ISS. Crewmembers use them to make breakfast burritos, hamburgers, and even peanut butter and jelly sandwiches, as demonstrated by Expedition 50, Commander R. Shane Kimbrough.
International Space Station era
The Space Food Systems Laboratory at the Johnson Space Center (JSC) in Houston is responsible for the testing, preparation, and packaging of U.S. food to be delivered to ISS. Today, crewmembers can choose from about 200 different items for their standard menu that can be augmented with some personal choices to include commercial off-the-shelf items.
Without any dedicated refrigerators or freezers for food storage other than a chiller to cool beverages and condiments, all food items on ISS are stored at ambient temperature and must remain stable in those conditions. Foods can be freeze-dried or thermostabilized to achieve the required shelf-life. The packaged food is then shipped to one of three launch sites for loading into resupply vehicles – to Cape Canaveral Air Force Station in Florida for launch aboard SpaceX Dragons, the Mid-Atlantic Regional Spaceport in Virginia to be loaded into Cygnus spacecraft or the Tanegashima Space Center in Japan from where HTVs are launched.
The U.S. and Russia each provide half of the food destined for ISS and the two partners share some food with each other. Before their missions to ISS, crewmembers sample the American food at JSC’s food lab and repeat the process with Russian food in Moscow.
Astronauts from the other ISS partner agencies such as the European Space Agency (ESA), the Japan Aerospace Exploration Agency (JAXA), and the Canadian Space Agency (CSA) often bring their own specialties that are shared among all the crewmembers. For example, for his flight during Expeditions 50 and 51, ESA astronaut Thomas G. Pesquet from France brought 13 dishes prepared especially for him by the French space agency CNES.
The most difficult foods to provide to long-duration crewmembers on ISS, and the most sought after by them, are fresh fruits and vegetables. Their short shelf life and the lack of dedicated refrigeration on ISS for food result in them being a rare commodity in orbit. A limited supply of fresh fruits and vegetables regularly arrives with each visiting vehicle and is eagerly consumed by the onboard crews.
Another option, exercised by Russian cosmonaut Oleg G. Artemev on both his long-duration missions, is to bring along your own, in this case, onions that he carefully tended and regularly snipped off the growing shoots to add as a flavoring to his usual dishes. A third possibility, so far only tried on a very limited and experimental basis, is to grow your own aboard ISS.
In 2013, after earlier trial runs that showed that eating the red romaine lettuce grown in the Veggie apparatus was safe to eat, Expedition 44 Flight Engineers Kimiya Yui, Kjell N. Lindgren, and Scott J. Kelly tried the space-grown vegetable and declared it delicious.
The first pizza aboard ISS arrived via a Progress resupply vehicle in May 2001 in a commercial agreement between the Russian Space Agency and Pizza Hut. Expedition 2 Commander Yuri V. Usachev reheated the salami-topped pie and filmed himself eating a slice in a commercial for the pizza company.
In 2017, Expedition 53 astronaut Paolo Nespoli from the Italian Space Agency casually mentioned that he missed one of his favorite foods, pizza. So ISS managers ensured that all the necessary ingredients were loaded on the next Cygnus resupply vehicle and Nespoli and his ISS crewmates had themselves an out-of-this-world pizza party. Needless to say, in weightlessness, it wasn’t enough to just eat the pies, spinning and playing with them was just too irresistible.
With the increased diversity of NASA’s astronaut corps as well as the number of international astronauts who have visited ISS, the variety of food available to all crewmembers has grown significantly. Astronaut Sunita L. Williams not only enjoyed Fluffernutter sandwiches with peanut butter on a tortilla to remind her of her childhood but Slovenian sausages to celebrate her mother’s culture and samosas to celebrate her father’s Indian heritage.
To help celebrate his birthday, French astronaut Thomas G. Pesquet had macarons delivered to ISS. Several astronauts from JAXA held sushi parties for their fellow crewmembers. Short-term visits by Space Flight Participants from several nations added culinary spice to ISS menus, such as satay from Malaysia, kimchee from Korea, and madrooba, saloona, and balaleet from the United Arab Emirates.
Despite the wide variety of foods available to ISS crewmembers, sometimes they crave that little something extra, either an extra sweet dessert or some comfort food item that reminds them of home. Although ISS doesn’t have a dedicated freezer for food, freezers destined to return science samples are frequently launched on cargo vehicles like SpaceX Dragon or Northrup Grumman Cygnus spacecraft.
Since the freezers often launch empty, they can carry items such as ice cream or other frozen treats for crewmembers to enjoy as soon as they open the hatches to the vehicles. During Expedition 42, Italian astronaut Samantha Cristoforetti from ESA enjoyed the first authentic espresso in space made in a device provided by the Italian Space Agency in cooperation with espresso maker Lavazzo.
In November 2019, the Cygnus 12 vehicle brought to ISS a Zero-G oven provided by Doubletree Hotels as an experiment to assess the possibility of baking in space. And just in time for Christmas, Expedition 61 astronauts Luca S. Parmitano and Christina H. Koch baked chocolate chip cookies that returned to Earth aboard SpaceX 19 in January 2020.
Great improvements have been made in the food available to long-duration crewmembers over the 20 years that ISS has been permanently occupied. The international nature of the program adds much-appreciated variety to the menu as crewmembers bring their culturally important food items to the dining tables on ISS.
Future developments in onboard technologies will certainly expand these already broad and diverse culinary horizons.