Growing plants in space has been proven and is being tested by NASA, however what would be the main protein source in a self sufficient station, crickets, soy, or could we raise animals in space?

Can I get any decent facts or sources why we should raise animals for meat in the first place? I'm sincerely interested in the topic! You can never get 1:1 ratio when feeding crops etc. to animals. It's always more efficient, when thinking of energy, to consume those plants by yourself. Of course, there should be overseeing of balanced diet - but that should be watched even when animals are used to ensure that people don't get extra problems from meat and dairy consuming.

Crickets would need total change of our attitudes towards them, at least if Western people are considered. Though they are high in efficiency. Soy should be monitored: I suppose GMO's ain't that good idea to carry on in space without really high class testing and monitoring. Seeds and nuts and other plants seem to be considered quite a safe possibility.

I agree that seeds, nuts, fruits and plant crops are safest to use as food in space. I think we should be very cautious with GMO as we know too little yet about its health effects. We can also look into circulatory aquaponics systems involving vegetables, fruits and fish. In terms of proteins also algae and fungi offer great possibilities. See: Aquaponics involving vegetables: https://en.wikipedia.org/wiki/Aquaponics http://smallfarms.ifas.ufl.edu/crops/aquaponics/pdf/sustainableaquaponicco-productionRTyson.pdf http://www.fao.org/3/a-i4021e.pdf Algae as protein source: http://www.foodbusinessnews.net/articles/newshome/Supplier-Innovations/2014/12/Analyzingalgaeasaplant_pro.aspx?ID=%7B50DA7A53-AA1D-4CF7-83E5-FB5D251326E7%7D&cck=1 Fungi as protein source: http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.499.1240&rep=rep1&type=pdf Warnings about GMO food: http://responsibletechnology.org/gmo-education/health-risks/

I agree, seeds, nuts, and plants should be a focal point in our diet in space. I know a lot of people have concerns about GMOs, but not all GMOs are harmful. So far, all of the plants that have been grown in space on the ISS have been genetically modified to grow in space because the scientists had to ensure the plants could grow in higher than average radiation levels and zero-g. Plants on Earth today are not capable of growth in the extreme environment that is space/ space stations. They have evolved on a world that protects them from the majority of uv blasts and radiation. (Ozone layer, magnetosphere). I do agree, also, that we will have to monitor them closely to make sure that they do not become harmful to us when consumed.

Until we can build environments that are equivical to Earth, there's not much sense entertaining long term habitation.

By setting up lots of "smaller" independant "farms" then it's possible to diversify to the point of producing every agricultural goods, and done "right" it can use pretty much the same processes as on Earth.

This has been circulating the web recently. I don't know if it has made the rounds on the forums here or not. It sounds like an interesting option to consider for those who don't want to give up the whole meat thing. Just something to consider for having that traditional protein from meat feel.

http://www.memphismeats.com/press-releases/

Food based on insects could actually be really beneficial as insects could be used also in various scientific tests - and they contain really high level of protein.

Are we talking about taking protein production that is grown on earth to space, or creating protein production systems in space? 

While currently still in a prototype phase, lab grown meat would be a wonderful protein source in space.  If we could miniaturize the process and equipment needed to grow meat without animals, we would not need to resort to worrying about the husbandry associated with bugs or the resources and space required for food plants.

Plants would be the best option, you can substitute the meat feel from plants (currently being done in the USA, tho i have heard that it is expensive at the moment).

I think that making sure that no citizen is suffering for malnutrition (protein, energy or any micronutrient) should be the main focus and then the energy (eletricity/power it takes to grow the food) effiency.

Если изменить митохондрии животных так чтобы они могли окислять водород и метан то мы получим мясо которое почти не надо кормить-хотя незаменимые аминокислоты и витамины надо выращивать с помощью бактерий.Так же и с растениями.Это на порядок эффективнее фотосинтеза.В принципе смеси водорода или Метана с кислородом не взрывоопасны при низкой концентрации горючих газов-так что можно генетически модифицировать и самих колонистов-либо модифицировать митохондрии яйцеклеток до оплодотворения либо модифицировать митохондрии стволовыхклеток

If you modify the mitochondria of animals so that they could oxidize the hydrogen and methane we will get meat that is almost not necessary to feed-essential amino acids and vitamins will have to be grown using bacteria.So it is with plants.It is much more efficientе then photosynthesis.In principle, mixtures of hydrogen or methane with oxygen is not explosive at low concentrations of combustible gases so that it is possible to genetically modify themselves and the colonists or modifying mitochondria of oocytes  or modifying mitochondria stem cells

Though i am a BIG fan of eating meat, the operation of raising animals in space on a station is fraught with difficulty and a few disadvantages as well. 1) they breath oxygen so we have to uses ours for them. 2) we have to raise food to fatten them up. taking more space and labor. 3)caring for them in general. 4) if one disease gets on board the likelihood of a total herd loss is very high in a closed group. 5) water usage and waste recycling. thats just some off the top. 

Now plants on the other hand turn our waste into something useful. and oxygenate  a station. can be a food source . nice to look at . can be medicinal . I will have to import bacon and vitamin d whole milk oh and cheese.

hmm... my mental is having a problem with that image in my head! but i'd be willing to try tasting it 

Who needs meat when we can grow Mushrooms and Spirulina ? :-)

The idea of raising animals in zero G for protein is, as some pointed out, a rather daunting task. If we were to go that route it'd likely have to be smaller animals that take up less space/use less resources. Crickets as some have mentioned or other insects would be a good choice there, beyond that my next suggestion would be a bird such as a chicken to provide an egg supply.

As for using plants and/or mushrooms. They provide problems of many of the plant based solutions for protein provoking common allergic responses to some people. So we'd need to make sure there was a decent selection to choose from eventually. That said, they are some of the better options since they could also help keep the CO2 levels down. I don't know enough about mushrooms to be able to advocate for or against them, but I do feel that they are more likely to be able to handle some of the issues of space than plants can.

Next on the suggestion of GMOs, I personally think those would be perfect, if not necessary, for space and for future colonies beyond Earth. Most GMOs given to the public are tested thoroughly to be as safe as possible, at least as much as any other food we consume if not moreso. Furthermore, they may be able to be modified to not only survive better in microgravity, but also to provide a boost to nutrition. I certainly wouldn't dismiss the need to continue studying them at the very least. The more we study and practice genetic modification, the better we'll be at it and the safer it will become as well.

Finally, it's quite the feat to make a fully self sustaining space station, but alas, on their own they'd never be able to have enough continuous resources to keep up the agricultural needs. Space stations will likely always need resupplies from planetside. They may be able to stay sustained for a while, but even when recycling waste there's a slow decline in what can be produced without fresh resources. I foresee symbiotic relationships between space stations and their planets. The planets provide the agricultural requirements while the stations provide satellite services, satellite maintenance, heavy industry work, and possibly even energy collection that can be sent down to the planet.