# How to ensure a fresh food supply on a space station?

I am sending a space station (Year is 2020-2030, so no antigravity stuff) into space, probably bigger than the ISS but not rotating/only a few modules rotate, so there are only small areas with gravity.

The question is...I do not want to feed my brave astronauts "space icecream" and dried vegetables and meat conserves that were liquified, but real, fresh food, just like it is eaten on earth.

I want my astronauts to have the following foods avaliable every day:

• Meat
• Fish
• Dairy (Milk, Cheese, Butter, etc...) and Eggs
• Healthy stuff (Veggies and Fruit)
• Potatoes, Beans, Bread, Grains, and other side dish stuff
• Unhealthy stuff (chocolate, sweets, chips, maybe hamburgers once in a week)
• Exotic/expensive foods (not every day, stuff like crab, caviar)

I also want to know, if I will have animals and plants, how big do the centrifuges have to be, and what animals or plants are better (are sheep or pigs better, and are carrots better than broccoli, etc...?).

EDIT: We want meat, not meat substitutes. This includes either a way to bring fresh meat from earth to the station, or having livestock at the station.

• How does one send a space station to space? Isn't a space station already in space? :) Also, I would recommend building the station in space rather than sending it there intact. – Frostfyre Jun 1 '15 at 13:55
• This sounds like you don't want a space station, per se, but rather a mini world. It takes a lot of space to raise cattle, let alone the space for a fishery. – Frostfyre Jun 1 '15 at 13:58
• There are a lot of foods you don't want to eat in zero-g. And cooking would be an absolute disaster. – DaaaahWhoosh Jun 1 '15 at 16:04
• Considering the biosphere problems, I'd be recommending meat comes out of a can. – Joshua Jun 1 '15 at 21:46
• You want to do this by 2020-2030 you'd better start building! – Mikey Jun 1 '15 at 22:19

Hydroponics can be used for veggies and fruit.
Others seems hard.
Animals spend much more resource, which means more weight have to be send into space. If you have a space elevator that's fine but this load is too heavy when using rockets.
As a reference, you may check how research stations in Antarctica get food supplies. They have similar situation like space station(Keep in mind their storage room is much bigger).

If you can find a way to grow veggies, you can make meat. All you have to do is find away to transform plant proteins, which are short, into long 'animal' protein fibers. It would also be a lot more efficient than feeding animals plants and then killing them for meat. Not to mention having to deal with all the waste the animals will produce. Beyond Meat already does something like that. And if you can make one type of animal protein, I guess you can make all sorts. It would also be easy to simulate exotic foods like caviar, its in the repertoire of many modern 'molecular cuisine' chefs.

Also, referring to Doubble22's answer, you'd would use hydroponics to grow your plants.

I would probably put a space station in Earth's orbit which just grows food which other craft can swing by to pick up supplies.

The best way to do this is to invent an entirely new method of getting things into space.

Lifting mass into space is expensive. It costs somewhere in the region of \$50,000 to \$100,000 per kilogram (source). This is why the food in space is so "delightful." Freeze drying makes it light weight as possible. It also preserves the food for a very long time. It is the ideal source of food for an astronaut.

There's a rule in biology: each tier in the food chain can support 1/10th its mass in predators. So ignoring the massive amount of infrastructure you'll have to launch into space, you are going to massively increase your mass requirements. Each person needs 2kg of food a day. If they eat grasses, that's 2kg. If they eat chickens, it's 20kg, instantly. You just added over a million dollars for every day worth of chicken-feeding grass you need.

The solution to this was mentioned in a comment by Frostfyre: You're not looking for a space station as much as a complete artificial biosphere. Unfortunately, we have absolutely no clue how to maintain small biospheres (they are a mystery to us), so the only option is to go big and go home. That way, once you haul up several billion gallons of water to support a small fishery which feeds your salmon fishery (they are predators, after all), you can at least recycle your costs.

The other option is a miraculous increase in the affordability of bringing food to space. Maybe have a space elevator that works. If you send down an equal mass of material every time you send something up, you only have to pay the cost of the losses (friction, etc.) each time. Then, not only would it be affordable enough to send fresh food up from the earth every day, they could probably pay for the station by offering tourists day passes.

• Note: space elevators will likely be surprisingly slow; they're more for moving large amounts of material than transporting people. – user3757614 Jun 1 '15 at 18:29

Does insect meat count as meat? Insects are supposed to be more efficient than most meat species (although chicken and fish can be comparable, locusts are probably easier to farm in space, and may be able to be fed on waste from your starchy crops). Adult humans suffer muscle-loss in zero-g, it's no great stretch to assume that food mammals/polutry would have trouble putting on muscle mass (the tasty bit) -- research may shed some light on this, though it's not the purpose. It has at least been demonstrated that insects can reproduce in space. (Last 2 links via wikipedia.)

The bulk of the calories would come from starch -- traditionally cereals or potatoes. You'd need a lot of light for photosynthesis. This would have to come from sunlight if you're somewhere inside the orbit of mars or thereabouts. Solar cells (40%+ in the lab) are more efficient than photosynthesis (2%) so as others have said, hydroponics but big panels to power the grow-lights. You'd need very efficient recovery of all organic waste for fertiliser and water.

Despite all this it wouldn't be a closed system -- there would be waste that couldn't be dealt with and deficiencies to be made up that you'd need earth to provide (water for example, you can't realistically recover every molecule). You also have to consider the oxygen/CO₂ balance which will need active control.

So the question becomes: Is it more efficient to ship all the food from earth, or to ship an ecosystem that will still need input from earth?

• Yes, small animals are better. Rabit might be a source of meat. Insects can be chosen to be efficient at recycling waste ans unetable parts and provide human food in the fewest steps. Maybe we'll eat frogs, who eat bugs, which eat garbage. – JDługosz Jun 1 '15 at 20:47
• The extra step to frogs (chicken will also eat bugs) is an extra inefficiency. I would guess that rabbits don't do as well in zero-g as insects -- I'll edit something in if I can find a link. – Chris H Jun 1 '15 at 20:49

Given that I don't think technology will deliver what you want by 2030, I instead have an answer which is maybe slightly further out.

There is a wonderfully wacky book titled 'The Millenial Project' by M.T. Savage that describes space habs which are inflated balloons in which the very outer double-skin contains a metre of water. This serves both as a radiation shiel, an environment for growing spirulina algae and other simple radiation tolerant organisms, and for human waste re-cycling.

The spirulina can be eaten directly or used as foodstock for animals and fungi.

Other non aquatic plants can be grown within the balloons (the actual hab consists of a balloon within balloon within balloon structure to facilitate resilience), using aeroponics.

Some smaller inner-balloons can be entirely water filled where non radiation tolerant water plants and fish can be farmed. Various studies have bred fish and animals like frogs, snails etc in zero-G.

The idea in the book is that the water and air content of the station is extracted from a captured comet brought into earth orbit. The balloon skins and other components are launched from earth and the whole thing is assembled in-situ.

I should say that this idea is not without criticism and some of the science in the book has been shown to be wrong, but you may find some of these ideas usable.

The most efficient means of feeding the astronauts would be to create a closed system which converts their wastes into food for algae and bacteria. The wastes need to be broken down either with concentrated solar energy (put a bulb in the focus of a large solar mirror and superheat the waste) or "burn" it in a super critical water oxidizer, although that piece of equipment is likely to be rather massive, needing to operate at 373.946 °C and 217.7 atm for the water to be supercritical.

Since algae and bacteria can consume this directly, there are no intervening steps or losses in the system, so it will be highly efficient, and with algae in the "loop", you also can generate oxygen for the astronauts to breath as well.

How well they will enjoy eating this is another thing altogether. The raw algae and bacteria will almost certainly not be appetizing, so the plant proteins and carbohydrates will have to be converted into a form the astronauts will want to eat. The overall efficiency and mass may or may not be better than a hydroponic garden, but it will almost certainly be much smaller in total volume than any greenhouse setup.

Vacuum/inert gas packs, irradiation, optionally also quick-freezing.

Three things - essentially - spoil food:

1. Pathogens (moulds and bacteria)
2. Oxidation
3. Desiccation (drying out)

Packing your foodstuffs in controlled atmosphere and/or vacuum packs prevents drying and oxidation. Then giving it a hefty dose of radiation will sterilize the food and keep it fresh for a very long time.

Irradiation has a bad rep because people in general have no idea how radiation works... they think radiation is kind of like a pathogen, that is it contagious. This is only partially true, and only for neutron radiation. Irradiate your foodstuffs with gamma radiation and it does not get activated. You just kill the moulds and bacteria, hence your food then stays fresh for as long as no new pathogens get in touch with it.

Quick-freezing is also really good because it deals with all three, with one caveat and that is that some foodstuffs do not react well to freezing. Water-rich foods - like fruit - tend to have the cells burst from the freezing (water expands when freezing, remember). this means that when you thaw them they act as if they have been crushed. But meat and veggies usually handle it real well.

Non-perishables - like chocolate and sugar - usually need no special storage conditions apart from being kept dry and in fairly "normal" room temperatures or slightly cooled.