Is mining ore worth it?

[Geschosskopf]

MJ would fit this bill very well.

No, it doesn't. There are several things you can tell MJ to do and walk away from it, and it will do them no problem. There are a number of things that MJ mostly does OK but then goes nuts with. For example, performing any burn. It's all good until the last 0.2m/s, then it chases the moving navball marker indefinitely. Such things require supervision. But even if those problems get ironed out, MJ can't string actions together--you have to give it a new instruction for each step in the flight. For example, you have to tell it to dock after it completes a rendezvous.

What is needed is X-like automation where merely you tell a ship to go continuously back and forth between 2 points carrying stuff, without having to spell out all the steps involved. So the ship itself knows it has to do an undock, a transfer burn, a capture burn, a rendezvous, another docking, and then back the other way, refueling itself as needed as it goes. Indefinitely. And also the stations at the ends of the trip making the stuff or using it somehow. Nothing like that exists in KSP.

[FlyingPete]

It's good for longer missions as you can afford to carry less fuel from Kerbin. This makes the overall spacecraft smaller. Something like an exploration of Jool's moons comes to mind. Basically, you need the mass of the mining equipment to be offset by the reduction in fuel requirements.

Another idea that comes to mind is to bolt some engines and a fuel refinery to an asteroid and go off exploring the system with it

[Edax]

I think one of the best reasons to mine/refine is that it allows your creations re-usability. The same spaceship you used to explore encounter Duna can be the same one used to explore Jool with mining. Since you can get the gas on the go with your own spaceship, you don't have to watch your precious design get chopped up by staging until all that's left is a capsule and a parachute eroding in Kerbin ocean. It allows the potential of spacecraft to last months in real time until they get thrown out of whack by the next patch.

[Boganaut]

I find ore mining to be a worthwhile exercise in that it does allow existing ships to be used on an ongoing basis. It has allowed me to re-purpose a number of assets and engage contextual contracts when they pop up. Plus I just enjoy setting up infrastructure around the solar system... And you never know when its going to come in handy! It does take a fair bit of time though. I'd say economically its been mildly beneficial, but not particularly necessary.

[Nich]

You guys need more bulk.

Has enough fuel that I should never need to visit minimus again.