Why colonize Mars and not the Moon?

[mfb]

100% recycling, no waste at all? Good luck.

The fact that the Moon is solid right down to the core, means that mines can be dug way deeper than on Earth.

Mines on Earth are not limited by the rock getting liquid. They are limited by temperature and logistics. What is the temperature gradient inside the Moon?
By the way, the Moon has a small layer that is partially liquid, but it is so deep down that it is not relevant.

The moon was once liquid - I don't see how volatiles in relevant quantities would be trapped anywhere.

As far as I understand the original source, they didn't find a cave, they found something that is expected to be an intact lava tube. Might need drilling to get in.

It does have some chemical activity.

Nothing compared to Earth, or even Mars.

 

[Al_]

To bring it back to the original question, why colonise Mars and not the Moon?
I think the English-speaking public, for a generation or more, have taken the initial Apollo findings that the Moon is barren, and written the Moon off as a potential site for a colony.
These ideas are deeply embedded in the scientific and technical world, even though, over the years, the evidence has been slowly swinging back in the Moon's favor.
The Chinese, and others, not having quite the same outlook or culture, have recently taken a keen interest in the Moon. We may soon find a colony growing there rapidly while the U.S. is still trying to make the long, difficult and dangerous voyage to Mars. And once a Moon colony is established it makes a really great launch pad to go everywhere else, Mars included.

Let's colonise the Moon first.

 

[mfb]

The Chinese have their Moon program for the same reason the US had the Apollo program. To show that they can do it, to test manned spaceflight beyond LEO, and to have a good near-term goal to look forward to.
The US did all that already. Launching a second Apollo program ("we'll land on the Moon again within this decade!") wouldn't help. The next goal is Mars.

Both projects are not colonies, however, those are beyond the scope of existing programs.

Launching things from the Moon is not necessarily cheaper. Building anything factory-like there would cost a huge amount of money, not all of it for R&D. Access to space will probably get much cheaper soon with reusable rockets - and building things on Earth is much easier than building them on the Moon.
But even if launching things from Moon stays cheaper for some reason, you don't need a full colony there to do so.
I had a look at the mice irradiation study linked a while ago. They irradiated the mice with dose rates between 0.05 and 0.25 Gy/min, for a total dose of 0.05 to 0.3 Gy. That is a total dose ~10 times the dose expected for humans on the way to Mars - but in a single minute instead of 6 months. What do we learn from that study? If you irradiate mice at 1 million times the rate expected on a trip to Mars, they can have issues with memory and other brain functions. Yeah... okay. So what? That's like testing an acceleration of 1 million g and then claiming that humans could struggle on Earth with 1 g.

 

[Al_]

99.999% recycling means you need very, very little input. Why would you vent used air or used water, or throw out fertilizer? Life support requires these things.

Mines on Earth are not limited by the rock getting liquid. They are limited by temperature and logistics. What is the temperature gradient inside the Moon?
By the way, the Moon has a small layer that is partially liquid, but it is so deep down that it is not relevant.
The moon was once liquid - I don't see how volatiles in relevant quantities would be trapped anywhere.

I concede that you are right. The temperature gradient is not known, but can be estimated with some simple calculations. I expect that volatiles are rare, on a planetary scale.
But we're not looking to fill an ocean. Just looking for the odd little places where a teeny tiny bit is collected together, say 100 tons or so. Miniscule.
Similarly with the chemistry. Rare, deep, historic, different, but enough.

 

[Al_]

Yes, they are similar programs, and not about colonisation, as you say.

At least not initially.

But just because the U.S. didn't take the next step to capitalize on it's Apollo success, doesn't mean the Chinese will stop at the same point. Especially now that the Moon looks a lot more enticing than it did in the Apollo years.
It would be kind of embarrasing for the U.S. to have to race back to the Moon. Almost an admission that they left stuff not finished. Maybe ESA will have to be the ones to ensure the Chinese don't have a monopoly.

There are technical challenges to manufacting in vacuum, but there are many compensating advantages.
Building a factory on the Moon would be very expensive, now. But when a Moon colony is esablished, less so. Eventually, the difference will be irrelevant next to the question: from where can move the most stuff to a destination further out in space?

Launching from the Moon is physically much, much, easier. Reusable rockets will work there, too. Making things on Earth is easier, at the moment, but getting them into space is always going to be harder than from the Moon, however cheap Elon's rockets are.

 

[mfb]

99.999% recycling means you need very, very little input. Why would you vent used air or used water, or throw out fertilizer? Life support requires these things.

No one wants to vent air or all used water. But what do you do with the most toxic waste? Do you expect to squeeze the last hydrogen atom out of everything?

The Chinese are looking at Mars already - it will be their next step after the current Moon program. They plan to go to Mars without a Moon colony.

Reusable rockets will work on Moon, but they are high-tech. The very last thing a colony will be able to manufacture on the way to get self-sufficient. You can launch them from Earth to Moon, but then you can directly use them from Earth as well.

 

[Ophiolite]

Apologies if I am repeating a point already made. I have not yet read the entire thread.

Evolution has gifted homo sapiens with an urge to explore and expand. That's why some of us left Africa. It's why we went, albeit briefly, to the moon. It's why our surrogates have visited every planet (and former planet) in the system. Regardless of the logic of colonising Mars our natures will compel us to attempt to do so, probably marginally before it is technologically practical.

 

[mheslep]

...got successful? Tesla did,

Successful in several ways, growing sales, growing revenue, and being innovative, but Tesla is nonetheless a business and has always lost money. Last year Tesla lost a billion dollars.

 

[mheslep]

Why not colonize say, the deep ocean instead of a lifeless moon or remote planet with the associated low gravity and high radiation problems? The exploration, the challenge factors are all there as well, and would be orders of magnitude easier and more feasible.

 

[clope023]

Why not colonize say, the deep ocean instead of a lifeless moon or remote planet with the associated low gravity and high radiation problems? The exploration, the challenge factors are all there as well, and would be orders of magnitude easier and more feasible.

Nothing that says you can't do both; Space Colonization is in general more exciting and finding unknown life in the oceans is still going to be 'simply' undiscovered Earth Life, while the possibility of finding truly Alien life will be a monumental moment in scientific history.

 

[Al_]

Nothing that says you can't do both; Space Colonization is in general more exciting and finding unknown life in the oceans is still going to be 'simply' undiscovered Earth Life, while the possibility of finding truly Alien life will be a monumental moment in scientific history.

Expansion out into space opens up far more potential for the future. Unlimited expansion. Unlimited resources.

No one wants to vent air or all used water. But what do you do with the most toxic waste? Do you expect to squeeze the last hydrogen atom out of everything?

I'm referring to human habitat waste - why would you create toxins in the habitat? As for chemistry and manufacturing processes, if they use up water, maybe find another process, or recycle that water in it's own closed loop.
It would be relatively easy to distill water using low pressure and so yes, you can recover almost every drop out of most types of toxic waste.

The Chinese are looking at Mars already - it will be their next step after the current Moon program. They plan to go to Mars without a Moon colony.

But my point is this - the (expensive) Apollo program stopped when people got bored with it. Now we have basically the same idea for a mission to Mars, and won't that mission just stop when people get bored? And for China it's the same kind of national pride to be the second nation to the Moon (they hope). Maybe the first nation to Mars, they will be hoping too.

But then they will stop. Because of the expense. This thread, and Elon's talk, was about colonisation. For that, the Moon makes way more sense to do first.

 

[Algr]

Hi All!

If your goal is to protect the human race from cataclysmic disasters, it isn't enough to just have colonies. These places would need to be economically independent - able to survive for centuries without any helpful input from Earth. Right now we can't even do that in Antarctica. I'd also point to the Biosphere II project that seems to indicate that we have no idea how to build an ecosystem on Mars that could provide food for us long term without massive constant input from Earth. It could happen someday, but sadly, I don't think I'll live to see humans being born on Mars.

 

[Al_]

Hi,

I think when we talk of colonies, we mean a settlement large enough to be close to self-sustaining, at a pinch. Or building up towards that point. If it grows fast and retains transport links to Earth, it will be hard to tell the exact moment it becomes possible to self-sustain.

The big difference is between a mission that just goes, makes footprints and returns (Not to belittle the Apollo science work!) and one that goes to stay, build, prospect, mine, learn, manufacture, grow and adapt.

 

[Algr]

Originally I was going to say "Right now we can't even do that in Alaska." but I remembered the native eskimos. Could we even make Alaska self sustaining without trade?

 

[pervirtuous]

There are a number of reasons to colonize Mars over the moon. Firstly and most importantly, there is evidence of water on Mars, so water wouldn't necessarily all have to be shipped there. That is the best reason. Also, the gravitational difference between the Earth and Mars is much less than the difference between the Earth and the Moon. There would be far less stress upon the bodies of the colonists. Thirdly, the moon does not rotate upon an axis, the time of light and dark would be very unbalanced. Somewhere on Mars, it may be possible to find levels of darkness and light generally corresponding to those on Earth. This would greatly enhance the experience by minimizing the changes for the colonists. From another angle, we are more interested in the history of Mars than in the history of the moon. The work done on Mars would, therefore, be more desirable than the same work done upon the moon.

 

[lifeonmercury]

Since the surface gravity on Mars is only 38% that of Earth's surface gravity, I imagine the people living on Mars would be much weaker than those who remain on Earth.

 

[rootone]

Since the surface gravity on Mars is only 38% that of Earth's surface gravity, I imagine the people living on Mars would be much weaker than those who remain on Earth.

That isn't in itself a problem - while they are on Mars - since less gravity means less effort is required to get some things done.
However, we don't know whether people adapted to Mars's gravity would be able to re-adapt to Earth.
What we do know is that long-term astronauts on the ISS lose body mass despite doing frequent exercise.
Recovery can take a year or more, and for some individuals there can be irreversible physiological change, (though not to the extent of rendering them disabled)

 

[houlahound]

Why choose from big rocks in space when floating space stations are already proven and are more feasible.

 

[Algr]

Space stations tend to be lacking in raw materials.

 

[houlahound]

Space stations tend to be lacking in raw materials.

Food you can grow, energy you can harvest other stuff you could mine from convenient sources.

Where I live the main industry is mining, the miners live hundreds, if not thousands, of miles from their work.

Its all FIFO: fly in, fly out.

FIFO is way more efficient than building permanent "colonies" at the site of mineral deposits.

 

[mheslep]

Nothing that says you can't do both;

Money, especially in the event colonization scales up to millions.

Space Colonization is in general more exciting

Perhaps. Certainly more hyped, more Hollywood. Space travel and exploration is exciting, with the danger being part of that; I suspect colonization would become much less exciting over time. In the event of an actual colony, it may be that the one affording 2 way simultaneous communication is more interesting.

and finding unknown life in the oceans is still going to be 'simply' undiscovered Earth Life, while the possibility of finding truly Alien life will be a monumental moment in scientific history.

Manned spacecraft and colonization of Mars are not required to explore for microbial life there. Also, If extraterrestrial life discovery is truly the goal, then it seems to me some kind of major investment in orders of magnitude better space based observation of remote solar systems is far more productive. Perhaps some interferometry with a 1000 instruments along an AU sized baseline.

 

[Algr]

Alien life on Mars would put the breaks on colonization because our presence would likely wipe it out, or turn us into terminator zombies.

Ceres might be a better place for a colony then Mars.

 

[rootone]

Ceres is similar to the Moon as an environment, but half the size and a lot more distant.
Unless there is something very useful there that isn't available on the Moon what why would it be better?

 

[Algr]

There IS something. Plentiful water. Mars and the moon would both have us trying to squeeze water out of damp sand.

 

[lifeonmercury]

If money were no object, could we establish a colony on the Moon within 10 years that could survive indefinitely if everyone on Earth died? Let's say every nation on Earth contributed 25% of its GDP for 10 years to achieving this. Would it be possible?

 

[Algr]

If money were no object, we could have started that in 1970.

 

[rootone]

If money were no object, could we establish a colony on the Moon within 10 years that could survive indefinitely if everyone on Earth died? Let's say every nation on Earth contributed 25% of its GDP for 10 years to achieving this. Would it be possible?

Possible yes, Feasible no.
There would be interminable politics surrounding which nations are entitled to do what with the colony.

 

[mfb]

I'm referring to human habitat waste - why would you create toxins in the habitat? As for chemistry and manufacturing processes, if they use up water, maybe find another process, or recycle that water in it's own closed loop.
It would be relatively easy to distill water using low pressure and so yes, you can recover almost every drop out of most types of toxic waste.

Every colony approach will need a lot of chemical industry, which will produce similar waste as on Earth. You can recycle it, yes, with a huge effort. But you can also dig up new ice conveniently located close to the station. But only on Mars.

But my point is this - the (expensive) Apollo program stopped when people got bored with it. Now we have basically the same idea for a mission to Mars, and won't that mission just stop when people get bored? And for China it's the same kind of national pride to be the second nation to the Moon (they hope). Maybe the first nation to Mars, they will be hoping too.

You brought up the Chinese Moon program...

I'd also point to the Biosphere II project that seems to indicate that we have no idea how to build an ecosystem on Mars that could provide food for us long term without massive constant input from Earth.

A colony on Mars would have unlimited supply of CO2 and ice, something biosphere 2 did not have. Unlike Biosphere 2, a Mars colony would not try to to mimic all sorts of different biotopes in it, and would focus on the most efficient plants to get food. Oxygen is a nice by-product, but not necessary.

If money were no object, could we establish a colony on the Moon within 10 years that could survive indefinitely if everyone on Earth died? Let's say every nation on Earth contributed 25% of its GDP for 10 years to achieving this. Would it be possible?

10 years sound super optimistic. Using the estimated cost of SpaceX's ITS (there would be several similar projects with so much money), but with single-use transport ships because we won't use more than one or maybe two transfer windows: $200 million for ~300 tons. Let's be optimistic and say $500/kg, mass production would help. $100 trillion GDP per year, 25% over 10 years: $250 trillion. That would allow transporting 500 million tons to Mars. At 100 tons per person (maybe pessimistic, but we don't have so much time for R&D), that corresponds to a population of 5 million. Not bad. R&D costs should be negligible on that scale, materials shipped to Mars should be much cheaper than $500/kg as well. Unfortunately scaling that far won't work: we cannot have 1/4 of the world population work on building spacecraft s. We don't have so many raw materials, and we don't have so many experts.

 

[mheslep]

Let's say every nation on Earth contributed 25% of its GDP for 10 years to achieving this.

For many of the developing countries in the world, there is no spare GDP. Cutting out a 1/4 in these places means cutting out the bone, i.e. the water supply, food, basic necessities.

 

[Dale]

Why choose from big rocks in space when floating space stations are already proven and are more feasible.

I do like the idea. Floating space stations can also be somewhat mobile to go to places where resources are, and then leave to go elsewhere.