At least on the surface of the moon, you're going to be in darkness for 14 days every 28. This not only means you won't be generating solar power, but your battery efficiency will probably also take a hit due to the cold temperatures (not to mention, you'll have to heat things too). So you'd have to have enough batteries for 14 days.
If you try a terraforming experiment on Mars and it fails, nobody's life/house/country/etc is ruined, which isn't true of geoengineering on Earth. I agree with the sentiment that there really is no Plan B to fixing climate change but that doesn't mean the goals of space colonization and fixing climate change are contrary.
Terraforming on Mars would take millennia, and over that long amount of time, settlement would presumably continue and the amount of colonists would grow. Thus, eventually flaws in the terraforming effort would eventually impact on local people.
Precious? The primary elements "wasted" in space exploration are aluminum, silicon, hydrogen, and oxygen. All of those things Earth is just lousy with. Even launching a rocket a day wouldn't put any sort of dent in the availability of any of those elements. A rocket a day also wouldn't meaningfully add to levels of harmful pollution. The Earth is really big. It has lots of pretty much everything.
Doing stuff in space is expensive in an economic sense but it's not really all that resource intensive. Most of the cost is paying people to design, test, fabricate, and operate the hardware.
Ok, but to put a rocket in space you need a surrounding economy on a specific technological level which is costly resourcewise. Could SpaceX or NASA happen in e.g. Congo, Nepal or Papua New Guinea alone?
It’s because the people interested in exploring and settling Mars are private citizens. Nuclear power is the domain of governments and/or highly regulated entities.
> the people interested in exploring and settling Mars are private citizens
which is what I argued against.
Also I'm pretty sure the national space agencies would like "colony of 1M people on Mars with solar power" too, and looking at the progress made they seem closer.
Or plonk three clusters of solar cells at 120 degree gaps and lay cable to connect them? No storms or weather to worry about damaging the cable and you'll always have power.
Getting 7,000 km of cabling on or below the moon’s surface and maintaining it (no storms or weather, but meteorites and radiation) may be the better choice, long-term, but I doubt it’s doable short-term.
Edit: it also won’t completely solve the power outage problem. The moon doesn’t receive direct sunlight at all during lunar eclipses, which can be over an hour.
Quote from Wikipedia : "the Moon's axis of rotation is sufficiently close to being perpendicular to the ecliptic plane that the radius of the Moon's polar circles is less than 50 km. Power collection stations could therefore be plausibly located so that at least one is exposed to sunlight at all times, thus making it possible to power polar colonies almost exclusively with solar energy. Solar power would be unavailable only during a lunar eclipse, but these events are relatively brief and absolutely predictable."
Calculate watts/kg for the total system, and be sure to include cost of heating, which comes nearly free with nukes, and you'll lean back to nuclear. The barrier to nukes is usually programmatic, not cost or technical.
I think this is referring to a nickel-iron battery, or NiFe for short. It's old tech, but is pretty indestructible. I have 20 of them in my off-grid system.
If building stuff is an option, 14 days might not be so bad.
You can store heat as heat, cooling as ice. They already need a huge water supply, why not freeze it for cooling?
Another option, unique to the moon. Why not just run wires to the sunny side. You could probably use uninsulated wire at a pretty high voltage. Nothing to disturb it or get electrocuted up there. You could do like 5 kilovolt on a hair thin wire to get usable amount of power across the moon with maybe 200lb of it
The short answer is reliability per watt. Solar's got lots of ups and downs which means designing bigger than you need. Batteries need replacing because they don't last forever. Solar panels have to be kept clean of dust on planets like Mars. Solar panels have to be deployed, which requires additional mechanisms that may fail or require human intervention, and so on.
The way they want to design reactors for next generation space exploration, they're set-it-and-forget-it designs. They have extremely few moving parts, and basically as soon as they're uninhibited, they'll run until something fails and their service life ends - likely several decades after construction. They're extremely reliable and are basically black-box sources of electrical power. Once they put it on the moon or Mars, they can just bury it under the regolith and run the cables back to where the habs are and forget about it. When it eventually fails, they can just leave it in the ground.
The biggest draw for nuclear power is continuous, autonomous processes, like thawing Mars permafrost for water, electrolyzing some of it for breathable oxygen and hydrogen, and using the hydrogen and carbon dioxide to make methane for return mission fuel for the complete in-situ resource utilization mission profile. These processes would run as soon as they were setup on Mars, without human intervention, and could run for months or years before humans even arrive, requiring no human intervention. Doing the same thing with solar would mean contesting with intermittency and having to actually assemble and maintain an enormous solar farm on Mars autonomously... We can't even manage that on Earth.
Certainly should weigh and cost less "the reactor cannot weigh more than 7,700 pounds..."