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Comment by Irregardless | Hacker News Reader

I doubt Musk would use his space colony as a means of enforcing his personal moral code, but I also suspect the diversity of plants required for a healthy vegetarian diet may be just as difficult to maintain on mars as livestock, so it would be very interesting to hear the full story.

In any case, there's no explanation of his motivation, and the statement is false according to this article that links to a (now deleted) tweet from Musk: http://thenextweb.com/insider/2013/01/10/good-news-elon-musk...

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> but I also suspect the diversity of plants required for a healthy vegetarian diet may be just as difficult to maintain as livestock,

People need protein, energy, vitamins, and minerals.

Getting calories from meat is inefficient; you need to feed the animal many more calories than you'll get back.

Meat is reasonably good source of protein. Getting protein from vegetables means mixing types to get the range of amino acids. There's a gentle concern about the lack of omega fatty acids in some vegetarian diets.

You get some fat soluble vitamins from meat and dairy products.

Meat is a good source of iron. Milk is a good source of calcium. But both of those can be found in vegetable products too.

tl:dr You need to grow vegetables anyway; meat is really inefficient; why waste energy growing feedcrops for animals (and for the people looking after the animals, and the people looking after the feedcrops) when you can jsut grow feedcrops for people.

> Getting calories from meat is inefficient

You're taking the model of an industrialized first-world nation with 300 million+ people and applying it to a tiny space colony. Calling that apples vs. oranges would be an understatement.

If you disagree, tell me this: How many 30,000 lb. John Deere combines do you think will be sent with the first settlers?

The model is the same everywhere.

We canna break the laws of (bio)physics, Jim.

No, it really is inefficient. A huge portion of the materials livestock consume get converted into heat and waste products.

And don't forget space - these would be domed colonies, so space would be absolutely critical. Here on earth humans have devised a way to raise food animals in a way that's (somewhat) reasonably efficient in terms of land used. But that method depends critically on armies of 30,000 lb. John Deere combines in order to produce sufficient quantities of feed crop without an enormous human labor input.

Using the model of 'small holding' - 5 acres per person style.

Goats provide:

Meat Milk Leather Bone Manure Farts Goat blood Useless baby boy goats

They eat. They eat far more calories than you'll ever get from them. Someone has to look after them, and that person also needs to eat.

Someone needs to grow the food for the goats, and for the goatherds, and that person needs to eat.

For a goat to produce milk it (like most mammals) needs a child to feed. Thus, you need at least one male goat for breeding. But male goats don't give milk. And they stink. And billy goats are just plain mean. So this stud-goat, stinky, mean, lazy thing, also needs food and care. And the birthing goat needs some attention. And if it's a male it's useless, so someone has to kill it.

All that time and effort, and all you get is goat meat and goat milk. Maybe some will think it's worth it, but other people would prefer using all that time and energy on a wider range of food.

> tell me this: How many 30,000 lb. John Deere combines do you think will be sent with the first settlers?

You have it backwards: Massive industrial farming makes things many times more, not less, efficient.

It seems to me that you could just feed your goat the parts of the plants that you can't really eat yourself. All the green crap from soybean plants for instance.

If that is worth it probably depends on how much goat milk is worth to you, how much the green crap is worth to you otherwise as compost, and how much goat crap is worth to you as fertilizer.

I don't think it would be worth it, but it wouldn't terribly surprise me if I were wrong.

I'm certain it's not an ideological goal, though perhaps it's being spun as one. Livestock simply might not be the most efficient way to produce food at least initially on a Mars colony.

Given an opportunity to live on Mars, I can't imagine any interested person who would have to think twice about becoming a vegetarian to do so, even if only out of necessity.

I'm no vegetarian, but it's pretty clear that it might be more efficient than raising livestock, or at least has the potential to be.

But there is more then just using them for food. Pigs for eaxmple can be used as a sort of biological recycling factory. In addition they produce _usable_ waste from _unusable_ waste. So your actually incurring a cost in not bringing them along that you will need some technology to replace. Then at the end you need to find a way to maintain or repair your technology while you could just mate the pigs and eat their parents. Additionally Bacon.

> Pigs for eaxmple can be used as a sort of biological recycling factory. In addition they produce _usable_ waste from _unusable_ waste.

Given some bacteria, fungi, and earthworms, there is little that composting couldn't also recycle.

Farms are basically solar collectors. Unless you have lots of excess capacity, it only makes sense to support livestock on kitchen waste. Studies were done on this in the 70's. It turns out that chickens laying eggs are more efficient than pigs for this purpose.

This is true, but its a matter of

1. Speed 2. By products

Chickens might be better then pigs, but the point is those little biological machines are really good at what they do and they are are easier to take care of/maintain then some machine to serve the same purpose.

Speed is not so much an issue if you're trying to stay long term. If you can find it, look up T. A. Heppenheimer's Colonies in Space. The "Up on the Farm" chapter was fun to read, and it has a pretty extensive set of references.

Farmed Tilapia might also be an option, though I'm not clear on how flexible their diet is.

I'd be more concerned about how flexible their habitat is. Mars doesn't exactly have a whole lot of water.

Actually, in the context of the solar system, Mars is pretty water rich.

http://en.wikipedia.org/wiki/Water_on_Mars#Polar_ice_caps

By Earth standards, it's drier than the Gobi desert, but for the purposes of colonization, there's plenty there to work with. The polar ice caps alone could cover the whole planet in an average depth of 16 meters of water. Also, there's the asteroids for when the population grows to a considerable size.

Absolutely. But in the more temperate regions there's not quite so much water, and shipping it in from the ice caps would be expensive.

For the first colonists, I'm guessing they'd want to make do with as little water as they could get away with - meaning there wouldn't be any raising of fish unless they couldn't get away with not raising fish.

> in the more temperate regions there's not quite so much water, and shipping it in from the ice caps would be expensive.

I'd see if I could use the atmosphere as a shipment mechanism.

> For the first colonists, I'm guessing they'd want to make do with as little water as they could get away with - meaning there wouldn't be any raising of fish unless they couldn't get away with not raising fish.

Farmed Tilapia ponds could serve as a reservoir of water/hydrogen. For a population in the 10's of thousands, it would seem to be a reasonable addition. For the first hundred, not so much.

Is genetically-engineered processed slime mold a vegetable?

If I recall correctly, from an energy conservation standpoint a vegetarian diet is somewhere around ten times more efficient.

> I also suspect the diversity of plants required for a healthy vegetarian diet may be just as difficult to maintain on mars as livestock

It's actually more reliable and easier to raise a diversity of plants for many indigenous horticulturalists on Earth. Monocropping makes you vulnerable to pests, and there's a nonzero chance of those being introduced by colonists.

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