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My impression is that we're getting really close to being able to launch substantial payloads to Mars relatively cheaply, but now that it's time to start packin

My impression is that we're getting really close to being able to launch substantial payloads to Mars relatively cheaply, but now that it's time to start packing we don't know what to send. We should industrially colonize the Moon. If we can produce oxygen, aluminum, titanium, iron, and glass on the Moon, it will make a bunch of other space infrastructure a lot cheaper. Solar Power satellites would become feasible, and then we wouldn't need fusion outside of having The Expanse-level of space military tech and other ultra high-spec space vehicle needs. And if we did have fusion, He3 would practically be a side effect of mining the other materials. Also, no natives with cultures and lives to ruin.

deleted 6y ago
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PeterisP 6y ago
If the justification investing into space/moon infrastructure will make constructing further space/moon infrastructure cheaper, then that's a circular argument, it's the "how, not why" about the most efficient way to produce some terminal goal, but it does not assert how large the benefit of that terminal goal is going to be. For earth needs, it's cheaper and simpler and more efficient to mine titanium right here. There's a reasonable argument that mining all these things for space needs could be more efficient if done "on site", however, what are those space needs that will ultimately somehow benefit the people of Earth in a way that's more efficient than doing it down here? If the end goal is to produce power, no matter how you invest into space tech, IMHO it's going to be much more efficient to build large quantities of solar panels on Earth and place them in Sahara desert, than to construct a large-scale solar panel industry on the moon to have the same quantity of power through satellites. Sure, they'd be cool, but that's not a justification. When/if there's a resource shortage on earth causing some minerals to be orders of magnitude more expensive than today, then it would be worthwhile, but not yet.
- outworlder 6y ago
  > If the justification investing into space/moon infrastructure will make constructing further space/moon infrastructure cheaper, then that's a circular argument Not really. If we have mining AND manufacturing capabilities outside Earth's gravity well, we can manufacture things very cheaply. Either things that require microgravity to be made, or things to be used in space. For instance, satellites. It would be much cheaper to build and launch them from the Moon. We could manufacture components which require vacuum and or microgravity on lunar orbital stations. > IMHO it's going to be much more efficient to build large quantities of solar panels on Earth and place them in Sahara desert How are you planing to send that power to, for instance, the United States? Disregarding the massive infrastructure requirements, there are serious power losses.
  - elihu 6y ago
    > How are you planing to send that power to, for instance, the United States? Disregarding the massive infrastructure requirements, there are serious power losses. I just got into this discussion the other day here: https://news.ycombinator.com/item?id=26599340 https://news.ycombinator.com/item?id=26599340 A commenter estimated the losses from North Africa to the United States to be about 33% with high-voltage DC. Wikipedia says this: Depending on voltage level and construction details, HVDC transmission losses are quoted at 3.5% per 1,000 km, about 50% less than AC (6.5%) lines at the same voltage. https://en.wikipedia.org/wiki/High-voltage_direct_current https://en.wikipedia.org/wiki/High-voltage_direct_current North Africa to North America is somewhere in the ballpark of 10,000 km. (1-0.035)^10 is almost exactly 70% (i.e. 30% loss). So, that actually sounds pretty reasonable.
    - stcredzero 6y ago
      Using microwaves to transmit power to receiving rectennas has already hit 70% efficiency. Exceeding that is very feasible. Once there is full industrial infrastructure on the Moon and in Earth orbit, building microwave antennas and ground receiving rectennas is going to scale a lot better than building more and more 10,000 km lines. For a community in the middle of nowhere building a rectenna will be relatively inexpensive, but the benefit will be like getting their own fusion plant!
elihu 6y ago
The moon and Mars have their pros and cons. The moon is closer and has a shallower gravity well. I think Mars makes a better destination, though, mostly because of the atmosphere which provides CO2 practically for free. With CO2, water, and electricity, you can make methane. (Mars might also have easier to find water, but I don't know offhand what the current consensus is on that.) I don't know if there is any practical way of creating fuel on the moon. You could launch things from the moon without fuel just by using a big railgun or equivalent, but these things will presumably still need fuel to slow down at their destination.

deleted 6y ago

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PeterisP 6y ago

If the justification investing into space/moon infrastructure will make constructing further space/moon infrastructure cheaper, then that's a circular argument, it's the "how, not why" about the most efficient way to produce some terminal goal, but it does not assert how large the benefit of that terminal goal is going to be. For earth needs, it's cheaper and simpler and more efficient to mine titanium right here. There's a reasonable argument that mining all these things for space needs could be more efficient if done "on site", however, what are those space needs that will ultimately somehow benefit the people of Earth in a way that's more efficient than doing it down here? If the end goal is to produce power, no matter how you invest into space tech, IMHO it's going to be much more efficient to build large quantities of solar panels on Earth and place them in Sahara desert, than to construct a large-scale solar panel industry on the moon to have the same quantity of power through satellites. Sure, they'd be cool, but that's not a justification. When/if there's a resource shortage on earth causing some minerals to be orders of magnitude more expensive than today, then it would be worthwhile, but not yet.

outworlder 6y ago
> If the justification investing into space/moon infrastructure will make constructing further space/moon infrastructure cheaper, then that's a circular argument Not really. If we have mining AND manufacturing capabilities outside Earth's gravity well, we can manufacture things very cheaply. Either things that require microgravity to be made, or things to be used in space. For instance, satellites. It would be much cheaper to build and launch them from the Moon. We could manufacture components which require vacuum and or microgravity on lunar orbital stations. > IMHO it's going to be much more efficient to build large quantities of solar panels on Earth and place them in Sahara desert How are you planing to send that power to, for instance, the United States? Disregarding the massive infrastructure requirements, there are serious power losses.
- elihu 6y ago
  > How are you planing to send that power to, for instance, the United States? Disregarding the massive infrastructure requirements, there are serious power losses. I just got into this discussion the other day here: https://news.ycombinator.com/item?id=26599340 https://news.ycombinator.com/item?id=26599340 A commenter estimated the losses from North Africa to the United States to be about 33% with high-voltage DC. Wikipedia says this: Depending on voltage level and construction details, HVDC transmission losses are quoted at 3.5% per 1,000 km, about 50% less than AC (6.5%) lines at the same voltage. https://en.wikipedia.org/wiki/High-voltage_direct_current https://en.wikipedia.org/wiki/High-voltage_direct_current North Africa to North America is somewhere in the ballpark of 10,000 km. (1-0.035)^10 is almost exactly 70% (i.e. 30% loss). So, that actually sounds pretty reasonable.
  - stcredzero 6y ago
    Using microwaves to transmit power to receiving rectennas has already hit 70% efficiency. Exceeding that is very feasible. Once there is full industrial infrastructure on the Moon and in Earth orbit, building microwave antennas and ground receiving rectennas is going to scale a lot better than building more and more 10,000 km lines. For a community in the middle of nowhere building a rectenna will be relatively inexpensive, but the benefit will be like getting their own fusion plant!

elihu 6y ago

The moon and Mars have their pros and cons. The moon is closer and has a shallower gravity well. I think Mars makes a better destination, though, mostly because of the atmosphere which provides CO2 practically for free. With CO2, water, and electricity, you can make methane. (Mars might also have easier to find water, but I don't know offhand what the current consensus is on that.) I don't know if there is any practical way of creating fuel on the moon. You could launch things from the moon without fuel just by using a big railgun or equivalent, but these things will presumably still need fuel to slow down at their destination.