Fuel vs Ore

[Grumpy Old Gamer]

Is it more efficient to bring up ore from the surface to be refined in orbit or is it more effcieint to refine it on the ground and then run the fuel up to the gas station. I mean total mass wise. I guess the real question is how much fuel does 1 ton of ore turn into, and how much does engineering skill effect this ratio. I can put up to 16 engineers in orbit, but only 3 on the surface. So technically 19 in orbit when the ship is docked.

[RoofCat]

large ISRU does 1:1 in terms of mass. Losless.
small ISRU wastes 80% with 5:1.

As for tanks, which is also important since we talk about space flight and mass, largest ore tanks are fine. They are in the middle between MK1&MK2 and heavier MK3. So not the best dry mass proportion nor worst. All other ore tanks just suck as "fuel" containers due to high dry mass. Largest ore tanks are also the most compact ones of all the "fuel tanks". Almost a Jumbo tank in half the size. Which may or may not be important.

[Grumpy Old Gamer]

Well, the lander has a small ISRU to regen its own fuel ont eh ground, where ore is infinite. I also power the whole thing with fuel cells, but I shut off the small ISRU before launch, and the station has the large ISRU and as noted, several engineers to boost efficiency.

[RoofCat]

1 engineer is all you need. High level preferable. They don't stack like scientists in lab except something has been changed lately.

[Ecclesia]

Originally posted by Dorf In Space:

Well, the lander has a small ISRU to regen its own fuel ont eh ground, where ore is infinite. I also power the whole thing with fuel cells, but I shut off the small ISRU before launch, and the station has the large ISRU and as noted, several engineers to boost efficiency.

I think ideally you would want to leave as many parts of the drill operation on the ground. The more items you transport to and from the surface of a moon (or planet) is extra fuel wasted. I tend to construct my planetary drills in two pieces: the bottom piece has the drills, radiators, batteries and solars. This part stays on the planet indefinitely. The top part is just empty ore tanks, a few radial thrusters (not RCS or Vernon) to park the top part right on top the bottom part for docking. This way you don't transport unnecessary weight to and from your orbital stations. (edit: the top part DOES of course have RCS / Vernons, but with radial thrusters I mean actual engines - either Mk55 Thuds, or have 4x Terriers built on structural arms so as to not destroy the bottom part of the drill when taking off or landing).

Also, you might want to try to have Asteroids being brought to your orbital stations, they are juicy sources of ore and take relatively little fuel to be brought to your stations compared to the amount of fuel you can get from them.

[Grumpy Old Gamer]

Yes, I have (pre-1.3) tried the asteroid thing. And I just finished the tech tree in my 1.4.2 career game, so roid wrangling is probably next on the agenda. But as I move towards exploring other planets, I would like to set up fuel stations at their outermost moons as I have done before. Getting the infrastructure set up for Jebediahs grand tour. Roids were always a big pain before. Mostly movign them to a new orbit. No matter how close I got to aiming at CoM they always seems to lurch to one side.