Ah, yes, the calfnapping alien. Transporting a cow onto a flying saucer with a laser beam has become a very popular way to satirize alien abduction tall tales. In real life, even if we figure out a way to transport cows to space, it will be quite difficult to care for them with a running space mission to complete. However, we are taught that meat contains protein, a very important building block for muscles. At the rate that astronauts are losing muscle mass, can we take space exploration to the next level without relying on animal protein?
There are many other protein sources out there, contained in plants, in insects, and in microorganisms. Alternative proteins, as they have been dubbed, could really be our ticket to deep space travels. In addition, they can provide a way to build food systems that are sustainable not only away from our planet, but also on it. Reducing animal farming is one of the necessary actions to mitigate global warming, after all. So, let's meet the alternative proteins!
Plant-Based Proteins
Plants are not just rich in necessary proteins and minerals, but they also contain protein! The richest ones are already being used to imitate animal meat: we have burgers made from soy, tempeh, tofu, chickpeas. This is how vegans have been sustaining themselves, and the stereotypes about them being skinny or tired all the time are totally not true! You might have heard that plant-based proteins are not as easy to be absorbed by our gut, but the difference is so small that it does not cause a concern - unless the protein intake is marginally low. You might also have heard that their composition is quite different from that of our proteins, but a varied, balanced eating pattern can counter efficiently this issue. The amount of vegan athletes proves that humans can really thrive on plant-based proteins!
A variety of plants has been grown successfully in space, and from a nutritional point of view, that is amazing. Regular access to fresh produce is paramount for health maintenance: plants contain many necessary elements that will be negatively affected by shelf-life extension processes (e.g. drying, or cooking at high temperatures). It is also acceptable for fresh food to contain helpful microorganisms, something not possible if we need to store the item longer. This contributes to a healthy gut, which is a quite rare occurrence among astronauts. Lastly, the psychological benefits of cultivating your own food are undeniable in the scientific community, as is the close relationship of emotional health with physical health!
Insect-Based Proteins
Insects are full of protein. It might sound as a disgusting food source, but insects are being widely consumed in many countries outside Europe. It is also worth noting that they are the main source of protein for a large number of primates, which are very close to us from an evolutionary point of view. Currently, crickets have been approved as a supermarket food ingredient in EU, and scientists are still busy with determining which other insects are safe and suitable for human consumption. They have identified 8 so far!
There can be plenty of solutions to increase acceptance and ease the mind: insects can be shaped as a burger, just like minced meat, or they can be ground into a fine powder that will add nutritional value to any protein-poor meal. Many people regard insects as dirty, but when raised for food, they will be kept in very clean facilities and regularly monitored for diseases, as it is supposed to happen with livestock. That doesn't make them much more difficult to care for, and taking into account that they need less room than other animals or plants, they might be just the thing for humans in space.
Cell-Based Proteins
By cell-based proteins, we mean the proteins derived by single-cell microorganisms, like yeast, algae, bacteria, or fungi. There are a few meat replacements from single-cell microorganisms already on the market, and, as we have done with nutritional yeast, we will keep discovering more and more about how we can fit them into our diet, in amounts big or small. As with everything food grade, microorganisms will go through exhaustive tests to verify that they do not produce any toxins or other harmful substances.
The good thing about microorganisms is that they require even less space, and the protein they contain is of very high quality. With a bit of modifications, we can even program them to feed on waste, meaning elements that we have no other use for! The potential to take us closer than ever to circularity makes them ideal for space missions.
Nutrition on Earth
When it comes to space travel, it might be a necessity to switch to alternative proteins, due to constrictions from the space environment. The necessity to exchange animal protein for alternative protein on Earth might not be apparent, but it is real. Reducing animal farming is one of the priorities in our race against climate change, and the transition to a more circular food production system will make sure that things do not get as bad in the future again. The fact that humans don't really need animal protein to thrive is a truly beneficial evolutionary trait we should take advantage of.