[DennisP]

If you want to go to Mars, it's way cheaper to get your return fuel from Mars instead of carrying it all the way to Mars from Earth. If you want to get your return fuel from Mars, then you have to make it, there aren't any convenient natural gas deposits that we know of.

This isn't an original SpaceX idea. Robert Zubrin pointed it out back in 1990 with his Mars Direct plan.

https://en.wikipedia.org/wiki/Mars_Direct

[lazide]

For sure - my point is, that presumes there is enough volume or an economic need to make that sort of infrastructure investment worthwhile (not even dollars, but energetically). Getting the direct equipment let alone supporting equipment there is going to be very, very expensive in energy. For one trip back, or even 5, it’s unlikely to pay off unless there is some cool super miniaturization tech and we’re not in a hurry - and that assumes everything keeps working over multiple missions.

And if we have all that, getting a mobile lab there and sending back bits instead of physical chunks of things is even easier.

You’d also need to get chemical feedstocks and process them (namely to extract the hydrogen, which is not readily available in the Martian atmosphere but is in the soil in various amounts in minerals and small amounts of dispersed water and methane ice) which would be non-trivial and a huge hassle to get even on Earth where you can go outside and smack the machinery with a shovel or stick your arm in somewhere to unclog something.

The existing Mars rovers struggle sometimes with dust on solar panels, let alone a broken bolt in a crusher due to harder than expected rocks or the like.

Having done some basic mining and a lot of earth moving over the years, it’s an incredible pain in the ass.

It’s also rare you don’t periodically need a human getting hands on, and using every bit of dexterity and strength they have to fix something. Robotic tech is nowhere near good enough to do this remotely.

So at a small, very very very slow scale? Maybe?

There are a lot of cool thought problems from all this, and some cool potential solutions. My fav is Project Orion [https://en.m.wikipedia.org/wiki/Project_Orion_(nuclear_propu...]

And we’ll just have to see what happens.