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Comment by transfire | Hacker News Reader

There is plenty to gain from it. But it is a long term prospect. Unfortunately today, everyone is after the quick profit (You know like building bombs.)

Some examples:

* A telescope on the moon could be larger due to the reduced gravity, and have a better view without the atmosphere.

* Helium-3 mining, not to mention plenty of other resources that are starting to become somewhat scarce and hard to reach on Earth.

* Since the gravity is a 6th of Earth's, launching space exploration vehicles from the Moon would be much easier and thus cheaper.

* Colonizing the Moon would be first step in getting all man's eggs out of one basket, so to speak.

* If man can setup a sustainable ecosystem on the Moon, then he can do so almost anywhere. It really is a great testbed for expanding into the cosmos.

* The Lunar Olympics will be awesome!

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For most of these, you don't have to go to the moon. On the way to the moon you get to space where there is even less gravity (Hubble isn't on the moon)

Having some gravity may be beneficial for the colonists, but AFAIK, 1/6th the gravity wouldn't help much there.

About the only reason for going there instead of into space would be to use materials present on the moon. Of the materials, Helium-3 seems the best candidate, but it is far out, as it would require extensive mining on the moon and transporting it back to earth or space or setting up a huge colony on the moon.

A second reason might be psychological. I think a moon colony, where one could make trips into the 'outback' for a few days, may have advantages for the long-term mental health of colonists (from a space station, people could go on space walks/flights for a few days, too, but such trips would look more like 'going nowhere'.

If we find a way to mine rocket fuel on the moon then we'd have a game changer. .. since you need far less fuel to launch from there than from earth.. that's what the moon base is about

* Since the gravity is a 6th of Earth's, launching space exploration vehicles from the Moon would be much easier and thus cheaper.

Could someone explain this to me? I understand launching a rocket from the Moon would be much easier than from Earth, but don't we need to factor in the cost of getting the fuel to the Moon in the first place? Would there be any benefit over just launching a bigger rocket from earth? In this layman's eyes, it looks like a zero-sum game.

The fuel could be made on the Moon rather than carried over. And one could also use some sort of railgun, since there is no atmosphere to get in the way.

There is reason to believe there is water frozen in a crater on the south pole of the moon.

If this is commercially exploitable, this could be cracked into hydrogen and oxygen or otherwise be used as fuel and/or reaction mass, so it would make a huge difference in the economics of going to Mars.

Another thing needed for long-range space travel is radiation shielding, and this can be as simple as a few feet of soil -- something which can certainly be harvested from the moon.

Probably worth noting that while all of these are potential upsides to going to the moon, really none of them are reasons why we should have been going back over the last 40 years.

Space telescopes costs shitloads already, and thats without having to land on the moon.

He-3 mining supposes a technology that doesn't even exist yet - we DON'T have fusion tech.

Launching exploration vehicles from the moon (instead of perhaps in orbit mating) implies an industrial base on the moon. The cost of doing this, especially with tech from the 70s through now is literally astronomical. It's not even a long-term prospect vs quick profit thing. It's not even a "new world" type thing. At least Europeans could enslave an existing labour force in the Americas.

We also can't even setup a sustainable ecosystem on the earth - we probably want to do that first before we try on the moon - see biosphere 2.

I don't want to be a negative nancy, but my point is that in my heart I really want to go to the moon for all these reasons and more. But just calling it a choice of "long term payoff" vs "quick profit" is a brutal over simplification, and also completely sweeps the costs and risks under an idealistic carpet.

Specifically a radio telescope on the far side would be advantageous WRT low radio noise.

Some kind of interferometer with one antenna on the earth and one on the moon would be interesting. Yeah more convenient to launch two satellites into opposite sides of the earth's orbit or something, but this is close enough to have human repair / maint / installation techs at both sides.

One nice feature of a base on the moon is single stage to orbit is technologically challenging on the earth but on the moon its no big deal. Ditto "no biggie" to build a rail launcher for non-living cargos or an elevator for cheap living cargo. In the very long run, there will be people/things in orbit occasionally eating luxury moon produce because it'll be much cheaper to orbit from the surface of the moon than the earth, or the moon will be the breadbasket of space, sorta.

You get 24x7 coverage of half the surface of the earth... I suspect scientists and soldiers will have lots of telescopes pointed at the earth.

Unlike robots or probes if you have humans with enough duct tape onsite, human lunar jobs can be changed in minutes instead of decades for dollars instead of billions of dollars implementing a new mission from scratch. Although never underestimate the ability of mismanagement to screw things up. Just like on the earth surface, doing the same boring predictable thing 24x7 for years unchanged is best done by a robot, and "hold my beer and watch this" or "hmm that result is odd" is best done by a human onsite.

These all seem like very sensible wins -- especially #6.

I think #5 is the most interesting, but my immediate first question, as a total layman for space travel/survival, is how do we keep breathing up there? It seems like solving the O2 to Moon transport is a reasonable problem to tackle -- assuming we get people and gear up there -- albeit a lot of effort. How about the next outpost? And then the next? Do we continue bunny hopping O2 transports from Moon to Mars to Earth2... etc until there is a continuous supply of breathable air out from Earth? Or do we have a way to generate as we go further? Are we at mercy of Earth's O2 supply? That seems like the biggest problem for leaving this planet.

Oxygen doesn't get used up. It comes back out as carbon dioxide. We would just need a way to extract the oxygen from the carbon dioxide again. One solution is photosynthesis, i.e. some plants.

> Oxygen doesn't get used up... We would just need a way to extract the oxygen...

Is that literally all there is to it -- minus reasonable loss? Does something like that already exist?

> i.e. some plants

Perfect! Do you think that plants can make up the loss from systems that we could set up for converting CO2 back to O2? When can fly some cows and chickens up there? Throwing plants and livestock on the Moon seems too good to be true.

Also, completely off topic, does anybody know the current value per acre of Moon?

There isn't really O2 loss from the natural process of breathing. Leaks in the pressurized environment would probably be a much bigger source of atmosphere loss.

Not sure you're getting what parent said. Oxygen is an element. It doesn't get "used up" in the sense that you have less. It simply gets bound in different forms (like more complex molecules). It just takes energy to release it so we can breathe it again. No loss (unless you run it through a fusion reactor).

Photosynthesis is one such process.

One useful thing, not currently used due to space, weight, and power issues, most of which would be minimal issues on the moon, is the Bosch reaction. Basically, CO2 + H2 => C + H2O. Split the H2O(water), and you get back the H2 to reuse in the Bosch reaction, and breathable O2.

Well, the question there is where does the Earth's O2 supply come from. The answer is what we should set up on the moon, a viable ecosystem. This means things like hydroponics, probably at least some algae based systems, that kind of thing. That way we can regenerate the CO2 back into O2, and get some food production along the way!

The moon is cheat-y easy

http://curator.jsc.nasa.gov/lunar/lnews/lnmar97/oxygen.htm

The TLDR is most lunar soil plus hydrogen and solar red heat gives a couple percent by mass oxygen in a couple hours.

So solar concentrators "boiling" vats of lunar dirt in the 14 day day, then tanks and nuclear powered LED illuminated plants during the 14 day night.

People don't use much oxygen by mass (although the volume is impressive) so a natural safety strategy is to melt chambers in the base so immense that you can survive a lunar night without any working O2 source. You'll want warehouse space to store "stuff" anyway.

On mars, a worst case scenario means you're a couple years away from the earth's surface (not just O2 or general environmental, but food and disease and sickness) whereas the moon is never more than a couple days from anywhere on earth. That's very convenient. I wonder how many years / decades moonies will "need" 100% lifeboat coverage like that. Eventually it'll make more sense to get self help from a neighboring colony than to abandon ship and fly back to earth.

#5 is fairly useless AFAIK, because the exact same problem applies to the bottom of the (deep)ocean, and IIRC the ocean is cheaper to get to.

Although the pressure problem is inverted, IIRC - space has zero pressure outside, whereas the ocean bottom has crush-depth pressure outside.

You get O2 from water, with some extra H2 to use in chemistry.

There's water (almost) everywhere.

>A telescope on the moon could be larger due to the reduced gravity, and have a better view without the atmosphere.

Couldn't a telescope in space be even larger, due to zero gravity?

Suppose we're modifying the James Webb to make it lunar based, wouldn't we need to add additional structural support in order for it to not collapse under lunar gravity? That would drive up the launch mass and thus cost.

Along with fact that telescopes are incredibly expensive to maintain while they're in orbit, having a lunar telescope would be even more expensive to maintain. Plus lunar telescopes would be presumably bounded to the surface of the moon, which would make them less flexible in terms of observation since it'd be locked to the Moon's orbit.

I keep hearing about Helium 3 mining but do we actually have fusion reactors nowadays (or even in next 10 years) that can use Helium 3?

No. We might have fusion power plants within a few decades, but those will use deuterium and tritium as fuels, not Helium-3. Helium-3 fusion has some advantages, but it's more difficult and it might not happen within our lifetime.

The telescope concept would be very cool to see done.

Oh, definitely! Look at how much more visible the stars were for the astronauts as they did their moonwalks! Imagine how much better we could see everything with a less cluttered view again!

https://google.com/search?tbm=isch&q=moonwalk+site:nasa.gov

https://en.wikipedia.org/wiki/Examination_of_Apollo_Moon_pho...

Does a lunar telescope have any advantage over a space telescope? Perhaps if we can build the telescope from lunar resources, it would be cheaper to assemble?

A radio telescope on the far side of the Moon would have the advantage of being shielded from all the radio interference from Earth.

I'm not sure that there are any advantages to placing an optical telescope on the Moon rather than in space.

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