People collectively do hard things when they are profitable.

Profitability here in most broad sense possible. US did not send men to Moon because it was hard. It was done because US was in a race with USSR and winning that race was profitable to US.

Having public opinion excited about some goal can be profitable, too.

If you don't believe, think about it: why has Apollo program been stopped? Because people got used to it and there was nothing further to prove -- further sanding people to Moon after US has demonstrated it can do it repeatedly was extremely expensive but there were no longer any significant profits from it.

So while it was still hard it actually became unprofitable to continue to do so.

If it was hard that caused US to send people to Moon, they would not stop sending people, they would be sending more, build base on Moon, etc.

Why do that if you have billions of flying bodies in much more convenient places flying around the Sun waiting to be docked to to extract resources?

1) This imagines only that there is no reason to extract minerals that far into the solar system.

2) It ignores that some technologies are much improved by proximity to the Sun, e.g.: Solar Sails are roughly twice as effective, which could change the calculus.

3) Mineral deposits may or may not be uniformly distributed throughout the solar system.

4) Mineral deposits may be more readily accessible than in other places.

> Why do that if you have billions of flying bodies in much more convenient places flying around the Sun waiting to be docked to to extract resources?

A space mining operation would need to offset a variety of costs. If you can land on Mercury and scrape up platinum powder with a shovel versus needing to completely process a 1-km long asteroid to get the same amount of platinum, it's not exactly de facto in favor of the asteroid.

Mineral surveying of nearby asteroids is certainly in its infancy and is likely to be where we get the bulk of our resources but I don't think it's quite so simple a case as you're presenting that closer to the sun = waste of time/money.

Mercury itself is light enough to cancel that out.

No, it does not cancel it out.

You need about 12km/s delta V to get to Mercury from Earth and then the same to get back. Remember, if you need to lift anything from Mercury, you need to actually transport fuel TO Mercury, before you can use it to lift anything out of Mercury.

And you don't just need twice more fuel for twice more delta-V. The fuel requirements grow exponentially.

Now imagine, how poor idea it is to transport mountains of fuel to Mercury just to get a tiny bit of what exactly? Raw materials? What kind of raw materials are present on Mercury that would warrant it?

For example, if you wanted to build a base on Mars using resources that you obtained somewhere else, it would actually require many times more fuel to get anything from Mercury than it would be to get it from Earth surface.

Tell me, how putting actual human on Mercury helps building a megastructure? It is not like they will be able to do shit while on the surface of Mercury. They would be just sitting idle in a single polar crater that happens to be shaded from Sun and have access to water. Then if you want to send anything to an orbit where you would want to build Dyson sphere you would actually have to expend more energy than if you tried to send it from surface of Earth. That makes absolutely no sense.

I think these types of megastructures will be built by swarms of autonomous drone ships that can collectively gather, transform and deliver resources, use gathered resources to produce more drones and use the rest of resources to build whatever megastructure has been programmed in.

- It is extremely metals and mineral rich, perfect for building the billions of giant mirrors required for a Dyson swarm.

-It's already really close to the sun, so you don't need as much energy to get your mirrors in a lower solar orbit, compared to earth.

-Because it's close to the sun, it receives a lot more energy too, which can be used to power machine and...

-It has no atmosphere and little gravity, so the swarm can be launched with simple electromagnetic mass drivers.

-It has plenty of water, so the few human operators required to control the machines remotely in real-time can live very comfortably at the poles (or in deep trenches in lower latitudes).

I agree that human colonization of Mercury is going to remain very limited, only because of the trouble of landing there. But you won't find a better planet to mine and launch billions of mirrors.