Re: Space X and the prospects of Mars colonization.

The moon has some very interesting aspects but it is depleted in certain key elements of the periodic table such as H, C, N. That being the case means the Moon cannot support life by itself, and also means many things cannot be natively manufactured there. (plastics, carbon steel, ...)

Mars does have a full set of elements. It is farther away, but the rocket energy required for Mars is a bit less than the Moon.

Cool. Thanks for sharing. It's nice to talk to somebody who seems to know so much. It's really interesting that it requires less rocket energy to get to Mars than to the moon. Does this mean that we could have landed on Mars already instead of the moon? It would kinda be funny if we had already been on another planet before we were on our moon. It would be interesting if we could just skip ahead 50 years and see if there will actually be any breakthroughs in space travel in the near future.

Well, how different is air travel 1968 - 2018?

Haha, good question. This reminded me of a Buzzfeed article I saw a while back. They are saying that air travel was actually better in the 1960s: https://www.buzzfeed.com/gabrielsanchez/air-travel-was-way-better-in-the-1960s. It did seem more spacious and fancy. I'm assuming it was much more expensive back then to fly relative to inflation than it is now. For the most part air travel doesn't seem to have changed that much, but I guess the planes have gotten bigger and they don't need to stop to fuel up like they used to usually. That last point is pretty significant in comparison to space travel. If planes can fly further now than they could 50 years ago, then maybe in 50 more years the spaceships will be able to fly further.

Probably so. But in space, everything is moving, so "further" means "longer." For example, the relatively huge ship displayed in "The Martian" is not unrealistic for a 2-3 year voyage for a half dozen people.