After almost a year in space, one of the astronauts on a mission on the International Space Station recently returned home. One of the first things he did when he got back was to sit down with friends and family to enjoy a proper homemade dinner, and then he Tweeted about it. This might seem unusual to some, but if you take a look at this infographic on food for astronauts, it will all become clear. Eating aboard spacecrafts is a totally different experience from eating at home, and not always a pleasant one.

There are several factors that make eating in space challenging. For one, there is the problem of microgravity. There is very low gravity aboard the International Space Station, which might seem cool to us who watch movies about floating around in astronaut suits. However, when everything around you that is not fixed floats all the time, including food, food trays and forks and spoons, it can get unnerving.

Also, the gravity problem results in another issue: the bodily fluids build up in the upper part of the astronauts’ bodies. This is the reason that the astronauts often feel congested, they can’t smell food properly and their sense of taste is diminished, so they often put a lot of ketchup or mayo on their food in order to make it more tasteful.

Low gravity is not the only obstacle to food being the same as on Earth. Since the astronauts spend quite a long time on their missions, they need lots of food stored aboard their craft, but the International Space Station is not made to store abundance of food. Lots of scientific experiments are conducted on the ISS, so the technical equipment necessary to conduct those studies and the equipment needed for the astronauts’ survival make it impossible to include refrigerators onboard.

That is why food for astronauts needs to be prepared differently. It needs to be packed tightly to fit the confined food storage space on the ISS, it needs to be lightweight and it has to be shelf stable for long periods of time. Most of it is freeze dried, which means that the moisture is almost completely taken away from the food and made into powder. Later, when the astronauts are ready to eat it, they need to rehydrate the food with hot or cold water, which makes it resume its previous form. However, these modifications take away a little from the food’s original taste.

NASA scientists that are working on astronaut food preparation are doing all they can to advance this process further. Take a look at the infographic and see why food in space presents such a challenge that even after 50 years it cannot taste quite like homemade food on Earth.

Evolution of Food in Space