How to Grab an Asteroid and Park It Near Earth

Then I would launch my asteroid mining spacecraft from other asteroids. A detour to Mars when you can just be in space seems unnecessary. Of course that depends significantly on what the mission is – if you're mining for your settlement on Mars, you'd do a lot of launches from Mars.

But if not and if you can lift all that's necessary for building and launching spacecraft to Mars, you can also lift it to an asteroid which will probably be significantly cheaper. Also bringing all the resources to support launches from Mars will be an enormous investment that would, at least in the short term, significantly outweigh any gain from using a shallow gravity well.

Asteroids are easy in that regard – you only need to find materials to refuel, your spacecraft needs only to make course corrections, which have different delta-v budgets and require less acceleration than launches. Impulse engines, VISIMR and all such fancy things are an option there. If only I knew anything about them.

Then there's the issue of spacecraft reusability and what do you use your resources for. If you want to bring your mined materials to Earth, you'd need to launch your lander back from Earth, because you want to reuse it, so there's no gain in a detour from Mars. The thing is, why the hell would you need to mine asteroids for Earth when it has enough resources to not need luxurious space resources yet. Presently you might need to mine asteroids for space, so obviously you'd launch from somewhere else in space (if you plan to reuse your deadly asteroid tow truck, if you don't – you'd still launch from Earth because you don't have a spacecraft factory on Mars yet).

 

At the very least, you might want a drydock/repair station in orbit of Mars as a way station, in case something goes wrong. You could even maybe have some bases built into Phobos and Deimos, where food can be grown in hydroponic gardens.
It would probably be easier to limp back to Mars than making the long journey home, and maybe there could even be a ship there for a retrieval operation.
That might be better than loosing a ship, because of damage from an asteroid collision.

And having a base can also be a place where the crews can take a break, or receive medical assistance if injured, before the long journey home. There could be stations that rotate to simulate gravity, unless the asteroid miners can do this.

I suppose there wouldn't be a need to refuel if you can get the compounds from asteroids as well.