Mine -> Convert -> Lift?

[MrOsterman]

So I'm trying to build a space based operations center using the mun as my source of ore to create fuel.  The end goal is having a gas station in space that I can send things to, top the tanks, and then send on to other worlds.  I also want to get the hang of using mining operations and ore to fuel conversions to work, eventually, towards a functional (and hopefully fiscally responsible) mothership build.   My thought there is that as I get contracts to get data from this planet or explore that planet, it will be cheaper to just send part of my "fleet" to rendevous with that planet rather than launch a whole new Kerbal based mission there.  That is a long term goal, though... step one?  Figure out mining.

I landed a science base on the mun, outfitted it with 900 units of ore storage, a full sized drill, 4 small radiator panels and a small ore to fuel converter.  I thought I was doing okay:

Here's my question:  Should I mine, convert to fuel and then lift the fuel to the station?  Or do you mine, lift to the station, and then convert there?  

Seems that the advantage of converting first is that you can use the ore you lift to fuel the trip up.  It also seems like by the unit, there is less fuel than there is raw ore, implying that the better route is to do the mine than convert.  But that also means rigging a lander with a converter and required radiator panels to run both a drill and a converter at the same time (or having to manually go in and tell the little guys to change gears every time the ore bays cap).

I also ran into the problem that my little base was about to blow up when I left the drill, and the converter, running at the same time.  I'm assuming that's because I only had 4 small radiator panels on it, but it's got me a little leery of trying to run that kind of operation as well.

[dangerhamster]

Someone clever will be along in a minute but in the meantime... aren't you making the whole operation less efficient by using Mun rather than Minmus? I have used mining ships to support operations on Minmus but on the Mun the higher gravity soaks up a higher percentage of the ore/fuel produced whichever way you do it.

[MrOsterman]

Well part of it is that I already had stuff at the mun to manage this and I've been doing mun trips as a routine for a while now so I feel comfortable sending and retrieving kerbals from it.  I also had a station in in HKO that originally been in a brief Solar orbit that I pushed into a Munar orbit since it wasn't that far off already.  That set me up to start working at the Mun first.  

That said, I really should have grabbed that "put a station around Minimus" contract when I had a chance since that is the logical "next step".

[capi3101]

@MrOsterman, I had a fairly convoluted set of mining operations set up in 1.0.2 on both Mun and Minmus. My own setup had a pair of converter units - one in orbit at the station, and one with the mining rig itself:

This is my Minmus rig, obviously. The drills, converter / ore storage / fuel storage units and delivery modules are each on separate landers, and they're interconnected utilizing KAS parts (winches and connector ports). Now, this was from 1.0.2, before waste heat from the drills and converters became a real concern - which is why you don't see any radiators on those landers at all. No reason why they couldn't be added for a 1.0.5 rig. Anyway, the point of the converter here was specifically so that the delivery lander (shown front right) could top off its tanks after reconnecting to the rest of the rig. There was sufficient storage aboard the converter unit that the lander could top off both its fuel and its ore supply instantly, requiring a delay for fueling the storage unit every other trip. The delivery module would take off and rendezvous with the orbiting station, which itself had another converter unit:

This is my Munar station. Here, the converter unit is towards the bottom of the station, with the delivery module docked at the time of the screenie (I apologize for the quality of the shot - it's the only one I have of the station, though). The ore processed at the station would be specifically used to refuel all the craft there - including the delivery unit itself. By having a converter at both ends, it was possible to build a lander with a very limited amount of delta-V while it was fully loaded with substantial amounts of ore. The system worked exceptionally well at Minmus. Not so much at Mun.

 

TL, DR; I'd strongly consider doing both - it gives you tremendous flexibility.

 

Edited December 8, 2015 by capi3101

[Red Iron Crown]

For a long-term refueling operation its better to convert on the surface and just lift fuel, that way you skip one rendezvous/docking evolution. I put the drills, convertor, and power system on a rover equipped with a claw. Land a tanker in an ore rich area, claw the rover to it, and fill 'er up! 

Orbital refining makes more sense as part of a mothership that goes from body to body doing a bit of mining at each. In this scenario I use harvesting landers that lift the ore back up to the mothership for conversion, that way I don't need to lug the ISRU unit up and down from the surface (though that might be a better strategy now that there's a lighter ISRU).

The other scenario is an all-in-one vessel that visits multiple bodies and lands on each, leaving nothing in orbit. In that scenario obviously all the ISRU equipment must be on the lander.

[mudkest]

for lfo/ox it does not really matter, 1kg of ore turns into 1 kg or lf+ox(or 1 kg or lf, or 1 kg of ore) so hauling 1kg of fuel or 1kg of ore, it doesnt really matter for delta-v if you refine on ground or in orbit.

Ore tanks are a bit heavier then lfo+ox tanks though, a 2kg ore tank holds 15kg ore, and a 2kg lfo+ox tank holds 16kg of fuel, so in that sens refining on the ground gives a bit more delta-v out of your mined mats, but seeing ore is unlimited(so the delta-v you get from a resource patch is also unlimited) in the ground that point is somewhat moot.

There is more sun-time in orbit though so the energy for refining in orbit is easier to get(less storage needed for the dark time, or less nuclear generators). You could use the fuel cells to power the refining, but then you use part of the product to keep production going. Not much of an issue with unlimited input, just get less fuel over time.

Monoprop, 1kg of ore gives 0.8kg monoprop, so delta-v wise it makes sense to convert on the ground(also more monoprop for 2kg of tank). But again, unlimited delta-v from unlimited ore so kind of moot. And how much monoprop do you need to haul up anyway?

[RexKramer]

While having a dedicated miner and converter on the surface, and only lifting fuel, is definitely the most efficient way to get fuel to orbit- there are a couple of advantages to lifting ore (and the drill too) to an orbiting refiner.

1. You don't need to perform a precision landing to get your fuel tank near the miner/refiner.  Eventually this isn't a big issue, but there is certainly a learning curve involved with performing precision landings.

2. Since you don't have to land your tanks in the same location every time, each mining trip to the surface can be to a different location or biome, allowing you to explore the planet while mining fuel.  Killing two birds with one stone.

I am now able to perform precision landings effortlessly, but I still like to send a miner down and lift ore to an orbiting refinery, to have an opportunity to explore the surface each trip.

[MrOsterman]

Hmm... I haven't mastered the rover yet and I don't really do all that well is precision landings.  I guess that's my next skill set to master.

I know I won't be sending down a science lab again, at least not with the intent of flying it back.  That or I need to redesign it.  Totally unwieldly and totally too big.  Took me way too much fuel to get it up back up into orbit.

Maybe I'll point my efforts (once I do a few contracts) towards setting up a gas station over Minimus and get some time trying to figure out rovers and how to mix and match purposes.  I've flirted with the idea of a base that uses a rover to either explore or to collect ore and bring it back to a launcher.

I do like the idea of landing a rover to mine and convert to fuel and then using a tanker rocket to ferry the fuel up to the station and then come down to get more again.  It does feel like I'll waste a lot of fuel in the landing and take off, but I should end up with a net gain.  In theory.....

Of course my last effort led to me getting my base back up in orbit, having to send out a capsule from the orbiting station, to the lander base, refuel it, and then fly the whole assemblage back to the orbiting station.  Which, rapidly, is becoming an unmanagable mix of parts,

I also need to watch a tutorial, I think, on how to have two docking ports docked in the VAB rather than manually docking later.

[Geschosskopf]

6 minutes ago, MrOsterman said:

Hmm... I haven't mastered the rover yet and I don't really do all that well is precision landings.  I guess that's my next skill set to master.

I know I won't be sending down a science lab again, at least not with the intent of flying it back.  That or I need to redesign it.  Totally unwieldly and totally too big.  Took me way too much fuel to get it up back up into orbit.

Maybe I'll point my efforts (once I do a few contracts) towards setting up a gas station over Minimus and get some time trying to figure out rovers and how to mix and match purposes.  I've flirted with the idea of a base that uses a rover to either explore or to collect ore and bring it back to a launcher.

I do like the idea of landing a rover to mine and convert to fuel and then using a tanker rocket to ferry the fuel up to the station and then come down to get more again.  It does feel like I'll waste a lot of fuel in the landing and take off, but I should end up with a net gain.  In theory.....

Of course my last effort led to me getting my base back up in orbit, having to send out a capsule from the orbiting station, to the lander base, refuel it, and then fly the whole assemblage back to the orbiting station.  Which, rapidly, is becoming an unmanagable mix of parts,

I also need to watch a tutorial, I think, on how to have two docking ports docked in the VAB rather than manually docking later.

Science labs are essentially useless since 1.0.  Prior to 1.0, they were the only thing that allowed you to reset Goo and Materials experiments for use in multiple biomes.  Nowadays, however, any beginning scientist can do that himself without a lab.  In return, labs can now manufacture science over time but the amount they produce is tiny and the time required is huge, so it's just not worth the trouble (especially if you use life support).  So since 1.0, I only bother with them at all when station and base contracts specify them.

Any sort of refueling operation within Kerbin's SOI is worthless from an economics POV and considerably more trouble than it's worth to use just as something interesting to do.  The only purpose served by doing it is to learn how the system works, so you can then use it at other planets where it actually makes sense.

Speaking of mining, from you original post, you had insufficient cooling to keep your stuff from exploding.  When doing cooling, pick radiators based on the "cooling required" of the hot part and the "core heat xfer" ratiing of the radiators.  The big ISRU needs 200kW, the small ISRU 100kW.  Each big drill needs 100kW, each small drill needs 50kW.  The standard arrangement is 1 ISRU and 2 drills all the same size, which means a big set totals 400kW and a small set 200kW.  The fixed radiators do 200kW (large), 150kW (edge), and 50kW (small), while the retractable radiators do 1000kW (large), 250kW (medium), and 50kW (small).  Retractable radiators generally run close to 100% efficiency because they turn edge-on to the sun, whereas with fixed radiators you'll need like 50% extra capacity to be safe, so I only recommend using retractables, for any application.  This means that to keep a big mining set cool, you'll need 1 large or 2 medium or 8 small retractables.  For a small set, you can use 1 medium or 4 small retractables.

Because all mined fuel is free, fuel efficiency in the process is not a major concern.  Provided you can get the quantity you need to orbit in 1 trip (so you don't have to waste time making several trips), you're all good no matter how much you consume making the trip :).  Thus, there's not a whole lot of reason to have separate ground-based mining/refining bases with fuel tankers flying the stuff to orbit.  Just having the whole thing fly is by far the simplest solution.

The main reason to go simple isn't so much the mass of moving ore as opposed to fuel, or even having to lift the ISRU and drills, it's because having it all in 1 vehicle totally eliminates the problem of docking on the ground, which is a bigger hassle than the pseudo-precision landing required before you can dock on the ground.  After all, your ground mining base can be a rover  Provided the tanker lands in the general vicinity, the base rover can just drive a fairly short distance over to it and drill and refine there instead of the tanker having to land right at the base.  Such a base rover just needs an ISRU, 1 or 2 drills, power and cooling for the machinery, some means of connecting to the tanker, and only 1 of the smallest ore tanks, nothing else (if it has power to run its machinery, it has enough power to move).  All the tanks for finished product are on the tanker lander.  So you connect rover to lander, start the drills, and ore goes into the small tank.   You then start the ISRU and product goes into the tanker.  Continue until the tanker is full.

The real trick in this is connecting the rover to the lander.  There are 3 methods.  Docking with ports is the worst and only really works reliably on the flats of Minmus.  It utterly sucks everywhere else.  Next there's the asteroid-grabbing "Klaw".  I still don't trust this due to kraken-invoking issues although Squad says they've solved lots of them in 1.05, plus it looks ugly.  However, it does allow totally crewless operation.  The final method is via the mods KIS/KAS.  I find this the most reliable method for making the connection, although there are some annoying bugs you'll run into periodically (always pack extra pipe ends and tools as some will disappear) and it requires an engineer on EVA to make the connections.  But OTOH, the whole mining/refining process works faster with an engineer aboard so you'll probalby have one available anyway.

[fourfa]

7 hours ago, Red Iron Crown said:

that way I don't need to lug the ISRU unit up and down from the surface (though that might be a better strategy now that there's a lighter ISRU).

Just in case someone gets inspired by this without looking at the numbers - the large ISRU makes 1kg of fuel from 1 kg of ore.  The small ISRU makes 0.1kg of fuel from 1kg of ore.  So lifting ore to orbit, then converting with the small ISRU is a Bad Idea.  Doing it on the surface, where infinity ore is free, is 10x slower but enables very small, lightweight ISRU ships if you're patient.

[RexKramer]

9 hours ago, dangerhamster said:

Someone clever will be along in a minute but in the meantime... aren't you making the whole operation less efficient by using Mun rather than Minmus? I have used mining ships to support operations on Minmus but on the Mun the higher gravity soaks up a higher percentage of the ore/fuel produced whichever way you do it.

Yup, mining Minmus is much easier than Mun.  However, there's a couple of good reasons to set up mining/refining operations at Mun-

1.  Ships at Mun need fuel.  Lugging the fuel from Minmus isn't an ideal solution, if you are doing a lot of operations at Mun having fuel there is handy.  Lugging fuel from Minmus to Mun turns out to be not terribly efficient.

2.  A mining operation that works at Mun will work well at Ike also.  So you can see how your Ike operation will function before hauling all the gear all the way to Ike.

[sardia]

1 hour ago, fourfa said:

Just in case someone gets inspired by this without looking at the numbers - the large ISRU makes 1kg of fuel from 1 kg of ore.  The small ISRU makes 0.1kg of fuel from 1kg of ore.  So lifting ore to orbit, then converting with the small ISRU is a Bad Idea.  Doing it on the surface, where infinity ore is free, is 10x slower but enables very small, lightweight ISRU ships if you're patient.

Why don't you use a mini drill, and a full size converter?  The mini drills give the same ore per second, but need less supporting power or radiators. There downside is a joke, you have to look for higher c concentrations. Oh the horror. Sarcasm. 

Time does matter, contracts expire and transfer widows come and go. 

[Plusck]

I considered a lot of the points here and decided... nah.

So my mining vessel is on legs, it has full-sized miner and converter, a couple of tanks for ore, LfOx, and Monoprop, and an engineer's cabin.

I know it isn't the most efficient set-up, but it can get up and down from all but the biggest bodies. It can easily join and resupply my orbital stations, it lands easily whether full or laden, and since it is a design-once-and-reuse element it can be sent up, dropped down, turned on, forgotten about and THEN when I need it it's all ready with fuel to supply what I actually care about.

I started making a more efficient, rover-based system to drop tanks on their own and be more efficient and whatnot, but after spending time on it I came to the conclusion that it was not my aim in the game.

So I'd say: if micromanaging resources makes the game truer to you, then go for the most efficient set-up possible and ignore me. If simply making sure your main missions have fuel is the main issue, then go big (because the small versions of drill or converter aren't worth it) but don't over-think the arrangement. It has to be available when you need it and forgettable the rest of the time. All-in-one, heat-dissipating and electricity-generating but still, just something you can reliably plonk down anywhere.

[MrOsterman]

Thanks for the responses guys.  I thought I was on to something with the "all in one" build (land, make your own take off fuel and then fill your ore tank) only I've got a different problem with my heat management so I was fishing for a solution there too.  My lander had 4 retractable small panels, one small ore processor and one large drill.  When left with both the processor and the drill running, it seemed everyone was happy.  But when the station passed into the dark side of the Mun, I'd come back later to see my radiators about to explode with fire damage.  Had the same problem after any long time warp.  

Is this a bug or did I do something wrong?  Seems odd that the radiators need sunlight or something to function.  I was also trying to run fuel cells to keep everything running but do the radiators need power?  I mean if I run out of electricity, shouldn't everything shut down until the sun is back in view and the batteries recharge?

[fourfa]

2 hours ago, sardia said:

Why don't you use a mini drill, and a full size converter?  The mini drills give the same ore per second, but need less supporting power or radiators. There downside is a joke, you have to look for higher c concentrations. Oh the horror. Sarcasm. 

Time does matter, contracts expire and transfer widows come and go. 

This isn't actually true - easily seen in a launchpad test.  The small drills pull 1/5 as much power, weigh 1/5 as much, and extract 1/5 as much ore per second each.  The tool tips unfortunately don't mention this part.  There does seem to be the same max ore per second, though except on the richest asteroids the max output makes no difference, you're never close to max output otherwise.

Again, this is very easily demonstrated, so throw a couple parts together on the launchpad or wherever you like.  There's a convenient readout in the drill's right-click menu, or watch the ore level change in the resource panel.

If you want to change the drill output (or the minimum threshold), it's just one simple line in the cfg file

Edited December 9, 2015 by fourfa

[sardia]

Curse it. I just asked about this a couple weeks ago. Does that mean if I have 5 or more mini-drills, I should replace them with the standard/big variant? Now I have to go redesign my mobile refinery rover.

Edited December 9, 2015 by sardia

[Plusck]

7 hours ago, MrOsterman said:

Thanks for the responses guys.  I thought I was on to something with the "all in one" build (land, make your own take off fuel and then fill your ore tank) only I've got a different problem with my heat management so I was fishing for a solution there too.  My lander had 4 retractable small panels, one small ore processor and one large drill.  When left with both the processor and the drill running, it seemed everyone was happy.  But when the station passed into the dark side of the Mun, I'd come back later to see my radiators about to explode with fire damage.  Had the same problem after any long time warp.  

Is this a bug or did I do something wrong?  Seems odd that the radiators need sunlight or something to function.  I was also trying to run fuel cells to keep everything running but do the radiators need power?  I mean if I run out of electricity, shouldn't everything shut down until the sun is back in view and the batteries recharge?

The only thing I can think of is the fuel cell.

Yes, radiators need electricity to run, but logically if there is no electricity then the drill and ISRU won't be running either. I've had red-hot engineers when they EVA to get swapped out, but no other heat problems.

So I'm guessing the fuel cells tip the heat balance too far. I haven't used fuel cells because in all cases it just seemed to be wasteful. Mining on any body other than an asteroid is slow, so why compound the slowness by using up the precious fuel you just made? And mining an asteroid gives only a finite source of fuel, so there again you don't want to waste any of it when solar power is just a manoeuvre away.

Since I haven't used fuel cells and haven't had serious heat problems, I'm guessing that either the heat produced by the fuel cells (do they produce heat?) or the continuous operation of your units with no down time at all, is what's causing the issue.

[fourfa]

1 hour ago, Plusck said:

I haven't used fuel cells because in all cases it just seemed to be wasteful. Mining on any body other than an asteroid is slow, so why compound the slowness by using up the precious fuel you just made?

Travel farther out (past Dres) and there's no choice but making fuel cells work

2 hours ago, sardia said:

Curse it. I just asked about this a couple weeks ago. Does that mean if I have 5 or more mini-drills, I should replace them with the standard/big variant?

Absolutely.