Every Sunday, this blog will offer analysis of a paper on space habitation and other related topics. These are my opinions on a weekly scientific paper. They are subject to my perspectives and believes. I am open to debate, so if any reader believes I have misinterpreted something in a paper, please point it out. I'm only a student and learning how to read these papers and interpret them. All quotes are from the paper unless otherwise noted. All papers I review are available for free online.
To design a space settlement many things must be considered, but if that settlement wants to be sufficient then they must build the settlement around the generation of food. But, in order to build around the food, one needs to know the diet of space colonists. This weeks paper explores that diet.
The paper suggests entomophagy, yes insect eating, to feed space colonists. Insects are a very stable and highly productive food source. Since there will be so little room on a mars colony, we can not risk the space resources on traditional farm animals who may die off. The paper primarily suggests vegetables as the core of the diet, but incests are included to make up for the lack of certain minerals in a vegetarian diet. As a vegan, I disagree with this statement the paper makes, but I am biased. The paper does point out that B12 and cholesterol can be obtained from plant life, but this paper is looking only at using the most efficient food sources and bugs are more space efficient than growing seaweed for B12 and mushrooms for vitamin D.
Assuming the space colony relies on trees, leafs would be a huge source of inedible biomass that incests can convert into an edible form. Insects are also a good choice as an animal food source because of their position on the food chain. “One level up the food chain, 80-90% of food energy is lost as dissipation of heat. This decreases the exploitable energy down to one tenth for one step up in the ecological system (Odum,1971)”. To best utilize leafs, silk worms where chosen as the staple insect.
The paper also suggests a few more foods to make use of the waste a space colony would produce. Chickens can eat any wasted vegetables, mushrooms can be grown on scrap wood. An “Aquatic fern, Azolla, is cultivated on the water surface of rice paddies for nitrogen fixation by symbiotic cyanobacteria” (Blue-green algae). Loach, a type of fish, can eat Azolla and can survive in low water quality.
The paper suggests rice as the grain of choice in space and soybeans to provide additional protein. Both crops have high yield for the room that they take up, the only problem is that soybeans are an “entomophilous flowering species depend[ing] on pollinating animals or their equivalent”. So, either the colonists have pollinate the crop themselves or they have to take bees with them. It could work out though, having bees would mean space colonists have honey. Sweet potato was also chosen for it's high yield per area of land.
The paper also suggests planting a crop called Komatsuna (Japanese mustard spinach). “Komatsu[na] is a fast-growing vegetable and is ready for harvest 35 days after sowing in warm climates” (1). Thus making it a great choice for the space colony which may have brought little food and needs a quick turn around. It also allows for an crop failure's impact to be reduced by just planting new crops. “It was found that a combination of 300g rice, 100g soybean, 200g sweet potato and 300g Komatsuna per day fills the nutritional requirement”. With Komatsuna filling much of the vitamin, iron and calcium requirements.
In zero gravity human bodies loss a lot of water. Any water that does remain moves to the chest and the head. All this increases the work the kidneys have to do, so a reduction in the salt intake is necessary.
I have a question for my readers: If this was your diet if you were to become a space colonist, would you go?
Sources:
(1): Author Unknown. Komatsuna (Japanese Mustard Seed). Oriental Vegetable Seeds - EvergreenSeeds. April 05, 2009
