[ianburrell]

I always wonder what resources from asteroid belt do we need on Earth. We have plenty of iron and aluminum for building things. Lithium and rare earths aren't available in asteroids. Gold isn't worth grinding up whole asteroid.

Asteroid resources would be useful for building in space, but that is getting a step ahead.

[mrguyorama]

Asteroid mining in our current economy is about pointing at the market price of an extremely low supply element that isn't that high demand in the first place and forgetting to talk about what a supply glut does to price.

Everyone is laboring under this subtle belief that space industry will be just like scifi speculated, but scifi stories always treated space like the ocean, with lots of interplanetary trade and easy travel and no consideration of energy (because it makes for good storytelling) but the actual energy budgeting and consideration of gravity wells is the exact opposite of ocean transport.

Global trade works at all because buoyancy and fluid physics make ocean vessels stupidly efficient at transport.

Moving any matter through space is stupidly inefficient.

The tyranny of the rocket equation constrains everything.