Orbital Mining & Refueling Ideas

[RoadHazard]

What's the collective wisdom on building an orbital mining and refueling platform?

My next challenge/boondoggle will be to mine ore on Minmus, convert it to fuel/oxidizer, and store it in big refueling tanks in Minmus orbit. But first...

Is it better to convert ore to fuel/oxidizer onsite, or to do the conversion in orbit?

Either way, is it better to send the entire mining/conversion rig back and forth between the surface and orbit, or to transfer the contents to some sort of tanker shuttle that takes it into orbit and returns?

Once the fuel is converted and safely in orbit, do you then bring craft to it for refueling (i.e., dock with the Minmus Orbital Filling Station), or send it to the waiting craft, or have a third craft (a tanker shuttle) deliver the fuel/oxidizer?

It seems like all of these permutations would work, but some must be more efficient than others. What is everyone's experience?

[GunsForBucks]

I am probably the oddball but I mine in the flats and bring ships down and dock to them for refueling.

https://steamcommunity.com/sharedfiles/filedetails/?id=2165441222
https://steamcommunity.com/sharedfiles/filedetails/?id=2638776895

Typically though if I am going outward from there I just build it with enough fuel to get where it is going. Refuel there if needed for return.

[Quizzical]

I've moved away from docking on the ground, just because bugginess is likely to make that cause vehicles to explode. If you do have vehicles dock on the ground, make sure that you have them undock immediately after transferring fuel. If vehicles are docked together and you switch away and then switch back, there's a decent chance that you'll get a big explosion that destroys enough parts to make one or both vehicles unusable.

For the larger planets and moons (Eve, Kerbin, Tylo, and Laythe), docking and refueling in space really isn't a viable way to make your infrastructure self-sustaining. You can kind of make it work on Laythe, but it won't get you very far. And on Kerbin, you can just launch more rockets, so there's no need to make it self-sustaining. So I'm going to assume that you're talking only about smaller planets and moons.

For the smaller planets and moons, you don't really need that much fuel to hop around between all of the biomes. One approach that I've used is to send a station with a Rockomax Jumbo-64 to a planet along with the lander, relays, rover, and so forth, but not any mining equipment. A small lander can refuel several times from the single, large fuel tank in orbit without any need for mining. That's good enough to land in all biomes on Duna or Moho without needing to refuel. See here:

https://steamcommunity.com/sharedfiles/filedetails/?id=2246157231

That lander is based on lander legs, though, which worked before the 1.12 patch broke them.

Another approach is to just have all of the mining equipment on your lander so that it can refuel itself. If your lander can do everything that you want to do on the surface, then there's no need to refuel. See here for an example:

https://steamcommunity.com/sharedfiles/filedetails/?id=2622946642

[AlexMBrennan]

A refinery in orbit is IMHO essential because the ships I want to refuel might need any combination of liquid fuel, oxidiser and monopropellant. Also, the spaceship might not be able to land.

As for the mining equipment, you could save fuel by leaving it on the surface but since you are presumably building these fuel refineries orbiting low gravity planets/moons I don't think that's worth the trouble.

Typically though if I am going outward from there I just build it with enough fuel to get where it is going. Refuel there if needed for return.

OK, but remember that most of the rocket's mass is fuel; emptying the upper stages (to be topped up at Minmus) will be far cheaper than launching a fully fuelled rocket.

[Bearded McGee]

I've done Minmus surface refineries, orbital dockyards, fuel shuttles, orbital refineries... every possible permutation I've done. What I've found is that the most expedient solution depends mostly on how good your PC is. If you can make and run huge crafts without issues, then making an all-in-one is just the most convenient thing you can do. Minmus is just that Easy to land and take off from, that your limiting factor isn't mass, but parts count. Other setups are, well, more efficient but vessel switching, docking, manually doing everything that needs to be done to operate a multi-craft fuel operation on Minmus.

Nowadays, I run an Extraplanetary Launchpad (plus Keridian) operation on Minmus, Gilly, Duna and Dres of all places. I run refineries for LF, Ox, LCH4, LH2, EnUr, Xe, Ar, AM, NSW, FP, FF, Mono, Li, Metal, RP and probably some other things I've forgotten (not to mention things I can extract directly like He3). My bottleneck is actually the Kerbals themselves. I could use a mod that allow me to turn some passenger modules into loveshacks of sorts and make more Kerbals in situ, but meh. Training is my second bottleneck, as I need Engineers mostly, that are also experience, AND have a low Stupidity score.

I think the biggest Lander-Refinery-Fuel Depot-Orbital Station craft I've made massed over a thousand tons, dry.

[Quizzical]

Actually, if it's for Minmus in particular, then why are you mining at all? What are you doing that makes it hard to just pack all the delta-v that you need? To go from a low orbit about Minmus to landing in every biome and back to orbit only takes about 2000 m/s of delta-v.

Here's the vehicle that I used to land in every biome, do all the science while landed (including deployable), and return to Kerbin:

https://steamcommunity.com/sharedfiles/filedetails/?id=2622947808

That's really intended for Bop and Pol, not Minmus, so it has more than 2000 m/s of delta-v to spare in each direction, which you could use to make the vehicle a lot smaller if so inclined.

[miklkit]

I'm more interested in spaceplanes than rockets, so I land them, refuel, then take off again.
https://steamcommunity.com/sharedfiles/filedetails/?id=2703017937

[GunsForBucks]

Originally posted by AlexMBrennan:

A refinery in orbit is IMHO essential because the ships I want to refuel might need any combination of liquid fuel, oxidiser and monopropellant. Also, the spaceship might not be able to land.

As for the mining equipment, you could save fuel by leaving it on the surface but since you are presumably building these fuel refineries orbiting low gravity planets/moons I don't think that's worth the trouble.

Typically though if I am going outward from there I just build it with enough fuel to get where it is going. Refuel there if needed for return.

OK, but remember that most of the rocket's mass is fuel; emptying the upper stages (to be topped up at Minmus) will be far cheaper than launching a fully fuelled rocket.

Typically if I am going outward or inward I am going straight up at sunrise or sunset. Stopping at minimus would just be a waste of fuel to me.

Perhaps if I played the game with more restrictive money settings it would matter.