Mining on Eloo; getting pratical

[fireblade274]

So ive been building a large re-usable tug that will tow with it a med/large sized lander. I found out that I can get to an orbit around Eloo, detach the lander, land, re-connects to the tug, and I had barely enough fuel to intercept Kerbin from Eloo. Even with 3 small and 1 med heat shield, the best thing i could do was use Kerbin as a gravity assist to lower my solar orbit as much as I could, and I had to launch a rescue mission.

I decided the best way to remedy this was to make the lander module (which must fit inside the MK 100 cargo-bay, I've allowed myself clipping privileges) capable of re-fueling after landing, and then making multiple surface to low Eloo orbit trips to gradual fill up the mothership completely, which will have no issues getting me back. This was my first attempt to use resource mining/conversion on planet surfaces: I needed to use the small drill and small ISRU to make the lander compact enough to fit my requirements, and placed one of each on the craft; 1 radial ore tank, 1 small isru, 1 drill. I placed 2 small radiators on the lander to cover heat, and I had 1 radioisotope generator (i failed to remember that energy generation was paramount in refining craft).

Keep in mind I did do my hw and make sure my landing zone had more 2.5% ore

When I got to Eloo the second time (this was yesterday, and this mission is in 1.1.2 where the previous was in 1.0.5) I as you can imagine vastly underestimated the requirements for "pratical" mining; it took 15+ days to fill my radial ore tank, and refining it all took less then 7 seconds, and gained me about 8 units of fuel and oxy each. In 20 min of doing this nonstop, i had only gained 100 units of fuel out of the 1000+ I needed to re fill it; AND i was banking on doing the trip multiple times to refill the orbiting tug.

In relation to my Eloo endevers, my questions are: 

• how many jr. drill o matics and cooling should I add?
• What energy system should I use? Obviously not radioisotope, but is fuel cell an option? How many Gigantor solar panels should I use if I go that route?
• Maybe something I'm not taking into consideration?

  Much thanks!

[SteveD80]

I would suggest replacing your mobile miner with a base. But in answer to your questions I will say that my mining operation on Minmus used full size drills and needed more than one gigantor per drill. I was able to run the drills over night using fuel cell, but I never tried running the converter off them I also found that each drill required a large radiator; I'd guess that the juniors will run off a medium. 

If your miner us manned make sure it has an engineer, the higher the level the better. And also try to mine in the highest ore concentration possible. 

 

 

 

[fireblade274]

Well here's what happened; I decided to send out an entirely separate ship to Eloo that will stay there and make refueling trips to the tug in low orbit. It holds 2/3 the fuel capacity of a jumbo fuel tank, and uses 4 1x6 solar panels, 2 Fuel Cell arrays, 4 jr. drills, an a jr. ISRU. the zone I land in is slightly above the min amount needed for the Jr. Drill to work. The efficiency is terrible; it takes 1yr 50 days to refill the fuel tanks, but it does work.

Any suggestions on how to make it more efficient? I think Ill replace the solar panels with the larger ones to take more load off the fuel cells, but I can only do it to a certain degree on Eloo since its so far away, especially during the apoapsis of its orbit. I think Ill also add 4 more drills maybe? but then that would take more power from the fuel cells, would it provide less benefit?

Also, @SteveD80 when your using the mini drill an engineer will help with efficiency, but they wont help efficiency with the mini ISRU, just in case you didnt know

[Warzouz]

I built a Exploration Space station able to refuel quite efficiently on nearly all bodies. For Eeloo, ot's quite easy, It can refill 60% of an orange tank per trip (which can refuel 5 times a 3000m/s science lander)

You have two options

• Creating a refuelling system to refuel other ships
• Creating a self sufficient lander which can refuel itself.

Personally, I always go for the first option. It's more versatile : you can change the landers, the facility will always be the same. It can also refuel return vehicle. So the first trip is the more expensive, then you only need to handle crew rotations.

Remember you need a lot of power. My design is not perfect because of that. I can't use fuel cells to power the mining. Many players prefer to add the refinery ON the mining ship. It's more efficient but less versatile.

 

[Plusck]

I don't understand why you are using multiple Jr. drills. They are inefficient, so if you are going to take more than one, why not just take the full-sized version? The large drill only masses 3x the mass of the smaller one, and has 5x the efficiency.

Likewise for the ISRU - I've only ever used the mini version once, because I had to land it on Tylo, and I'd never use it again if I could possibly help it. The small one weighs a third but has 1/10th the efficiency. Admittedly the mass difference for the ISRU is significant, but still...

Total mass for full size drill + ISRU: 5t. Total mass for 4 jr drills and jr ISRU: 2.25t. Eeloo is comparable to the Mun, so you can land a 5t payload with a single Spark and FL-T400 tank.

[Starhawk]

Having played around some with the small ISRU parts I will say this: go big or stay home.

There is a niche for the small ISRU parts, but it's a really small niche.  If you must have a small form factor / low mass craft with ISRU and it will stay in the inner system you can make the small stuff work.

If, OTOH, you are going past Duna you will want the large ISRU parts and fuel cells to power them.  The small parts are too inefficient to practically power them with fuel cells, solar panels don't work well enough out there, and RTG's are heavy.

My current mining / refining ship has four large drills, the large refinery, and six fuel cell arrays.

Happy landings!

[Snark]

5 hours ago, Starhawk said:

Having played around some with the small ISRU parts I will say this: go big or stay home.

^ This.

The small ISRU parts are practically worthless, in my experience.  Just don't bother with them, they're not worth the hassle.  Launch a ship that has actual full-size ISRU oand drills on it.  If it doesn't fit in the cargo bay you want, then either get rid of that requirement, or design a mission that can work without ISRU.

(Hard to say more than that, since I don't know the reasons behind your cargo-bay requirement.  Just launch an ISRU ship by itself, if you need to, and dock it to the Eeloo mission in orbit before heading out, if need be.)

As for power supply:

• Don't even bother with solar panels at Eeloo.  You get more power per kilogram from RTGs.
• Of course, RTGs won't supply the massive power needed for drills and refining.  Fuel cells are good for that.
• However, fuel cells only work if you're above the break-even point, which means that you need to have good mining efficiency per kilowatt.
• Having high mining efficiency per kilowatt requires basically three things:
  • A reasonably high-level engineer.  Level-0 at minimum, but if you can manage a level-2 at least, it'll help.
  • A good high ore concentration
  • Not using the worthless, hideously inefficient small ISRU parts.

So, in summary:

• Big ISRU parts
• Fuel cells
• Engineer
• RTGs for power when you're not actively mining/refining.