Sunday, December 15, 2013

A modest proposal: How to get massive public financial support for a Mars colony

One of the nagging questions regarding a Mars colony is funding. Sure, some think they have that solved, but only via cutting a lot of corners.

So I ask; wouldn't it be better to go with massive financial support? Yes, it would, and the good news is there's an easy way to get it - while doing a lot of good along the way. 

The answer, in brief, is to use the SLS as the launch vehicle for the numerous launches required, and more importantly, having it live up to its moniker: Senate Launch System.There's also the point that this is probably the only way the SLS will ever be of worthwhile use.

What I'm proposing here is to make Congress, all of it, the colonists, while also asking people to donate via the slogan "Send Congress on a one way trip into space!" I guarantee that the money would flood in. 

Convincing Congress to go is the easiest part; simply point to polls showing that voluntarily leaving Earth would make them very popular with the electorate, and whisper in their ears the magic words "guaranteed reelection!" 

As for the colony, you wouldn't need to worry about (or spend money on) implementing ISRU, life support, or any other infrastructure. Congress, once on Mars and when in need of something, could just do as it usually does and vote for it, paying no heed to any practical considerations whatsoever. If they need food, they can simple tax the locals - being a rock is no excuse for not paying taxes. If they need water, they could appropriate it by legislative fiat. If they are hindered by the low G, they could simply amend the  law of gravity. If they're a couple of days from running out of oxygen, they can simply declare the issue an "Oxygen deficit" and thus ignore it.

But why stop there? Let's do this right and send all politicians on this grand adventure to create a thriving, livable world - called "Earth".

Saturday, December 7, 2013

Water issues on Mars

When it comes to deciding where to place a colony on Mars, one issue oft overlooked is water availability.

Mars has water (which is what makes it the best choice for colonization) but it's not evenly distributed. Some areas are akin to the moon, where water can be found only in tiny concentrations. Extracting it via mining and heating would be enormously costly in terms of energy and infrastructure, even if we assume that Curiosity's results of a water concentration of 1.5 to 3% for Martian soil are representative of other areas of Mars. 

What this boils down to is that unless a colony is located near the north polar ice cap, you probably need an aquifer.  There may well be liquid-water aquifers on Mars, and in fact there almost certainly are. However, we don't know where they are yet.

Synthetic aperture radar may be the answer. A technique has been developed, but it has yet to be utilized on Mars.
JPL has an article about it, which highlights the fact that it's proving quite useful here on Earth. (I"ve often said that one of the prime "exports" of a Martian colony will be innovations in technology, and this is an early example; a technique developed for Mars being used on Earth).

However, even if aquifers are located, that alone isn't enough to select a colony site. Even here on Earth, wells still come up dry even when over a well-mapped aquifer. There are also cases where groundwater has unwelcome substances in it, such as arsenic or salt, which would require the water to be distilled (not a deal-breaker, but something you'd need to know in advance). So, what you need is a test well if an aquifer is your source.

Drilling a well on Mars would be a daunting, expensive task. It could be done with automated systems and robotics, but it would require a lot of mass. The drill pipes alone would weigh many tons. You'd need such a rig to drill a well for a colony anyway, but it's still a lot of upmass.

That leaves us with near-polar sites. There, water access is easier and definite; we already know there is water there, and it's on the surface in the form of ice. That saves the up-mass of a drilling rig, and the need to drill pre-site-selection. The only downside to such a high latitude site is that it reduces the available solar power, primarily during winter (Due to Mars' thin atmosphere, sunlight is not hindered when the sun is closer to the horizon, as it is on Earth). You also might need sunlight for greenhouses.

There's a way around that issue, a better way; nuclear power. With it, you don't need energy storage as you do with solar. For farming, you can use LED lighting, which you may well need even in an equatorial location; sunlight on Mars is weaker than on Earth due to distance, and would be further reduced by passing through the needed thicknesses of glass needed to deal with the near-vacuum of the Martian surface. Plants needing full sun on Earth would not do well in Martian sunlit greenhouses (though reflectors could be used to compensate).

Small reactors are closer to being available than is commonly thought; the Department of Energy and several companies are working on small modular reactors now, and those designs could easily be modified to reduce mass via dispensing with some shielding (On Mars, the shielding could be soil.).  

Via exchanging a small, lightweight nuclear reactor for the drilling equipment and solar collectors, you'd actually save net mass, as well as enabling the colony to be in a more advantageous location and be energy-rich. 

Edit to add: I'm not saying that a reactor is a prerequisite for a Mars colony; it isn't. However, if one is available, I think it would be preferable to solar-based energy for a colony.

Sunday, December 1, 2013

Food on Mars

For a Mars colony, food will, of course, be a critical issue.

The situation is simple; they can either produce food, or import it from Earth. The latter is very costly, especially long term, due to the price per pound of getting it to the Martian surface.

There are ways to reduce the mass of transported food, such as via dehydration. However, the cost will still be enormous. As Ken said in the post below, around $76,000 per kilogram.

What this means is that colonists will need, in a fairly short timeframe, to produce most of their food.

As has already been noted on this blog, farming should be one of their first tasks. This is a nececity, and fortunatly, there appear to be no show-stoppers in using Martian soil (It might need preprocessing to remove some iron and most perchlorates, both of which are easily accomplished.)

Therefor, within a few months, the colonists ought to be able to be harvesting many fast-growing crops. Yeilds could be increased via the simple expedient of increasing the partial pressure of CO2 (this has been often demonstrated here on Earth in experimental greenhouses).

However, there is a serous issue that I've not yet seen addressed; farm animals. Some will be vital, such as earthworms, though fortunately those are not hard to transport. What is of concern is meat animals; without them, the colonists will be condemned to exist as vegetarians.

During the early days of a colony, they will be unable to afford the production losses of using their farm produce for animal feed, but that should soon change. Then, they will need meat animals.

This begs the question, one I've yet to see raised anywhere; how do you get farm animals to Mars?

For chickens and turkeys, the answer seems obvious; send fertile eggs and incubate them on Mars. However, this is not as feasible as it sounds, due to the time constraints on per-incubation storage. A fertile chicken egg has lessening chances of developing after a few days, and after three weeks, incubation is impossible. Turkey eggs are better, but only by about an extra week before incubation percentages drop to zero.

It takes approximately 21 days of incubation for a chicken egg to hatch, while a turkey egg takes 28. So, if eggs were launched inside an incubation system that held them in cold storage first (for a maximum of about two weeks to maintain a sufficient incubation percentage) your hatchlings would emerge approximately 5 weeks after liftoff (6 weeks for turkeys) 

The key problem; a minimum-energy Mars voyage takes about 6 months at minimum.

Can hatchlings survive in zero G, even with humans aboard to care for them?

The answer, sadly, appears to be "no". The Russians performed some experiments on their Mir space station, which included hatching quail eggs.

Does this apply to chickens and turkeys as well? We don't know, though the evidence from the quail experiments is hardly promising. Even incubation in zero G caused issues.

The zero-g incubation issue can be dealt with via a small centrifuge, but even so, that would require a journey time of no more than 5 weeks. Therefor, it's quite possible that the only way to get chickens and turkeys to Mars is to do it very fast; a small craft on a very high-energy trajectory. The fastest probe ever launched was New Horizons to Pluto, and that took 78 days to cross Mars' orbit. What we need is something that can do it in half that time. This can be done; a very small Mars entry spacecraft launched by a very large rocket with multiple upper stages could attain the needed velocity, though engineering it to enter and land with an entry speed of over 100,000 mph will be an engineering challenge, and very costly.

What of other needed livestock; pigs, for example? Pigs might have a good chance, though they have, as yet, not been flown in space. All we have to go on are data from other animals, such as dogs, cats, and monkeys - and none of that is long-term. Theoretically, If launched young, piglets, if cared for by a human crew, could probably survive months in zero-g. Or, they might not. We simply do not know.

Sending cows to Mars (A single female calf would suffice, along with a stock of frozen fertilized eggs to be implanted) would be harder yet.

There might be one way around the zero-G issue. Artificial gravity. Connect two Mars-bound transport habitats by a long cable, and then spin up the resulting assembly. In this way, the need to make a fast transit could be eliminated. It may, in fact, be the only viable alternative.

The need to send livestock to Mars might be a longer-term concern, but it is something that will need to be done at some point in the early years of a colony.