This brings up a good point. Why mars first? Why not a moon colony first?
So you can grow plants in some kind of transparent pressurized place... Just like on the Moon.. or on a space station
You can use ISRU and atmosphere resource extraction to generate rocket fuel on the surface of mars, rather than being restricted to the rocket fuel you bring with you.
Ultimately, the answer is Mars has the necessary resources and when you look into the details just makes more sense and is easier.
That depends entirely on the effect in question.
You'd have a hard time pressurizing the moon's atmosphere to harvest it for propellent.
In the long run, there should of course be settlements on both bodies.
A space colony would have much more need to get supplies from Earth.
Once we've learned how to run a space colony on the Moon, building a second one on Mars would be much easier.
None of those problems exist on Mars. Others exist, but you can't just directly say it was easier.
Tourism would be an obvious sustainable Moon industry. That does fit your description :)
I see this as a disadvantage; the major difficulty of space exploration is getting out of the Earth's gravity well. I don't think it's wise to fall back into another one.
The point of the booster for Earth is both to get out of Earth's gravity well and through its atmosphere (both of which are far less of a problem on Mars).
The moon also has a small gravity well, but no real resources to help you escape it. Mars has a bit of a gravity well, but has many more resources to help you escape that gravity well.
Mars' soil contains tons of perchlorate at levels which are very toxic to humans.
TBH Venus seems like a better candidate for long term terraforming.
You can build floating complexes in it's upper atmosphere, and it has enough oxygen and water locked in it's atmosphere and we might be able to fix the rotation and the density of the atmosphere in one go by using the atmosphere to speed up the rotation of Venus. While both of these are quite "far fetched" technically, as far as terraforming goes we aren't any closer to terraforming mars than Venus, and at least for Venus we don't need to figure out how to give it a magnetic field.
https://en.wikipedia.org/wiki/Atmosphere_of_Venus#Induced_ma...
Additionally the current theory is that if Venus will be sped up to below 56h per rotation it would regenerate it's intrinsic magnetic field which should be near earth levels.
And while Venus does have higher gravity than Mars, it's still lower than Earth's, and overall the delta V for venus insertion orbit is slightly lower than what you need for Mars.
That's great and all, but how exactly do we realistically speed up the rotation of a _planet_?
The mass of the venusian atmosphere is high enough for this to actually work and still leave you a lot of atmosphere to work with, it will take 20-30 years but it still doable.
But compressing acidic gasses makes the corrosion problem worse, doesn't it? How do you deal with that?
This is planetary engineering. It's not supposed to be fast.
Unless, of course, you are a Kardashev II civilization.
As far as terraforming goes, Venus is just a better candidate for long term colonization.
Mars is much smaller than Earth. From Wikipedia: "Mars is less dense than Earth, having about 15% of Earth's volume and 11% of Earth's mass, resulting in about 38% of Earth's surface gravity."
Ref: Old man's war.
Of course you want the first colonists to not be sickly, but they won't need to be Olympic decathletes in their 20s. Equipment for lifting heavy objects can be sent more cheaply than people (it can go slowly and doesn't need life support).
I think for a venture like this maturity and patience is going to be more important than physical strength. There will be a lot of tedious tasks with long checklists that need to be followed near exactly to succeed. There will be a lot of disappointment and frustration when things fail or timelines slip. There will be the irritations of being stuck in a small social circle with a few people you intensely dislike but have to depend on for survival.
Add in the fact that your sperm or eggs will probably get exposed to large doses of radiation until they figure out how to get to Mars faster, and it will be far less attractive to anyone who is planning to have kids someday.
in my own personal experience, this thing works worse for older folks, who get territorial, grumpy and so on. But we aren't discussing folks in their 40s, rather 50s and 60s
We can try to explain solar system formation through mathematical models and simulation (Phobos and Deimos would be clues) but we can't go back in time and find the real explanation. No law of physics mandates that Mars' rotational period should be similar in magnitude to Earth's.
On the moon it means you need enough solar power in batteries to power your gear, and to power appropriate spectrum lighting for plant growth.
If you can rely on solar power more reliably, then you can construct (significantly more complex than those required on earth) green houses which still benefit from natural light.
I actually agree that there are numerous challenges associated with very long days and nights. Artificial lighting per se is not among them. Solar power is a reasonable one.
I guess direct to Mars is sexier. :)
(I'm behind live too.)
Its biggest, and perhaps only, advantage is that it has an atmosphere, and gas is so much easier to deal with for ISRU than anything else, as you don't need to mine it: just open a valve and suck it in. I notice Musk's ISRU plan is to mine ice; I do wonder how he's going to do that, as it won't be easy.
But... you know what... if you can get to Mars, you can get anywhere.
If you can get to Mars, getting to the Moon is so trivial you might as well build and maintain a base there just to test the equipment.
If you can get to Mars, you can get to near-Earth asteroids with enough spare capacity to take a whole a mining plant in tow.
If you can get to Mars, Ceres is only 400 m/s further away. (And Ceres is interesting.)
If you can get to Mars, then the outer solar system is reachable (with preparation and some disposable boosters).
If you can get to Mars, anyone who can afford a IST ship can have a space station.
So, hell yes, let's go to Mars. (And I'll cheerfully wave goodbye to you from my ice-mining cometary habitat.)
Mars first has the enormous advantage that it's tangibly in progress, however early, rather than being a great NASA idea that isn't getting funded. So I don't actually care which if only one is having rockets built. I saw enough artist impressions in the 80s. ;)
My recollection of the NASA idea was a Mars voyage would reconfigure/refuel at the space station but never land on the moon. The moonbase is the warehouse, fuel and whatever else would be needed to keep space station fed, and gets developed into manufacturing.
Lower G meaning larger vehicles, lower launch cost and so forth. The station at L2 was supposed to be a good jumping off point for anywhere - Mars, asteroids, rest of solar system - supposedly the most fuel efficient way to all(?) of them from here.
It's a while since I last read about that, so I may be mistaken on details.
The Moon's not very sexy. It's all dusty blacks and greys. Everyone knows it's a dead rock, we've already been there, and public consciousness is dominated by the Apollo program pictures of astronauts in gigantic, bulky spacesuits.
(This is mostly perpetrated by NASA unaccountably not sending any decent rovers to the Moon. Even the most recent lander, China's Chang'e, deliberately landed in the most boring place they could find. There aren't any interesting pictures of the moon because we haven't been anywhere interesting.)
ISRU's hard there, too. There's water ice you can mine, but carbon? I don't know where you'd get that.
But... if I were building a water ice mining plant destined for Mars, I'd want to test it somewhere. The Moon's a good place. So now I've landed an ITP ship with a mining rig. I'm going to load it with scientific instruments, too. And scientists. In fact, I might as well land two; it's good practice for Mars. And we're mining water, so we might as well use it, and help test the recycling systems. After all, the Moon's close enough that you can dash back to Earth in an emergency; it's the ideal place. We've got two ships; let's use one to recycle the crew on the other, and leave it there long term; there's plenty of interesting science to do, and it's all excellent practice.
So I'd be really surprised if a long-term presence on the Moon didn't sneak into this plan by the back door. And then if a carbon source were to be discovered in large enough quantities for meaningful ISRU, then sourcing methane from the moon would slot neatly in.
Getting water on the moon is a completely different problem then getting water on mars. Testing these things on the moon is totally insane anyway.The moon has some water, we don't know how much, and not exactly were it is. Mining it would be extremely difficult, specially without a nuclear reactor.
As for recycling systems, we are already good at them. We can and do test them on earth. We do test them on ISS. There is no need to go to mars, to these systems.
On Mars the most important resources for ISRU is easily and everywhere available, on the moon that is not the case.
The Science on Mars could answer fundamental questions about live, that is almost impossible on mars. Mars is clearly far more interesting from a scientific perspective. That is not even a point worth debating.
I am all for going back to the moon eventually, but mars is far more important. If you want to go to mars, go to mars.
Anything without an atmosphere you have to carry the fuel to stop after chasing it down, then land on it slow enough not to die. For robotic missions we can approach these objects in very favorable orbits with transit times measured in years, so the delta-v needed to slow down is manageable.
For human-based missions we have to get there fast. Going there fast means you have to dump alot of speed to stop once you get there. Without an atmosphere, that takes fuel. Not as much as it took you to reach that velocity, since you're lighter now, but still just about as much in terms of delta-v.
I learned this playing KSP. It will open your eyes to the real challenges of orbital mechanics. The hardest planet to land on in the entire game is the one with a mass/gravity approaching the game version of earth, except with no atmosphere. The in-game numbers aren't realistic, but the concepts are.
And hell yes, lets go to Mars. Where do I sign up?
Load up the icy dirt into a chamber using a digger, heat it up and precipitate out the water vapor. The only potential problem is separating out other volatiles, but fractionation is pretty basic tech.
Provided you have a decent power source that's easy: the hardest part is getting your raw material into the chamber and disposing of the debris afterwards. Humans driving flat-pack bulldozers, most likely.
Would work on the Moon, too.