Cost of different fuels.

[Dodgey]

The way I see it is that if you are able to launch an empty orange tank into orbit and recover it full for less fuel than a full orange tank worth of fuel you are returning more fuel to Kerbin than you are taking away from it, resulting in a net profit.

[Alshain]

But why buy fuel from Kerbin when you can use free fuel you brought back to KSC? If you earn back what you sold it for, it's exactly the same as using it yourself.

Exactly the same, except the cost of re-lifting it off the surface.

Also, why convert it to LFO? Convert it to Xenon. That's where the real money is.

I like the idea of the asteroid best. If you could land it, you could drill it and process it on the ground. Spawn a fuel truck with empty tanks, drive it to the asteroid, fill it up, and recover.

The converter doesn't have a Xenon option. There wasn't one when Ronin Pawn was drilling Minmus.

I like the idea of the asteroid best. If you could land it, you could drill it and process it on the ground. Spawn a fuel truck with empty tanks, drive it to the asteroid, fill it up, and recover.

Same deal here. You are better off leaving the asteroid in orbit for refueling than constantly lifting the fuel weight off the ground.

Edited April 26, 2015 by Alshain

[basic.syntax]

I like the idea of the asteroid best. If you could land it, you could drill it and process it on the ground. Spawn a fuel truck with empty tanks, drive it to the asteroid, fill it up, and recover.

rotfl ! - I am sooo going to try this! But, will not likely land it with nearly as much style as you did

edit:

The converter doesn't have a Xenon option. There wasn't one when Ronin Pawn was drilling Minmus.

Agreed, EnterElysium's YT vid doesn't show that option, either.

Edited April 26, 2015 by basic.syntax

[Superfluous J]

So you're better off buying fuel for $x/ton than you are bringing fuel to Kerbin for less than $x/ton total mission cost.

Okay I concede. We live on different planets

- - - Updated - - -

rotfl ! - I am sooo going to try this! But, will not likely land it with nearly as much style as you did

Neither can I, especially in the new atmo.

[GoSlash27]

So you're better off buying fuel for $x/ton than you are bringing fuel to Kerbin for less than $x/ton total mission cost.

Okay I concede. We live on different planets

Well... looking at it as a rational exercise, it kinda has to be that way.

When you recover your tank of fuel, they pay you (say) a thousand credits for it. Then you turn around and buy it right back for a thousand credits. It's like moving money from your left pocket to your right pocket; the transaction may as well not have happened.

So basically what you're doing is deorbiting your fuel, keeping it in a temporary fuel tank, putting it in another rocket, and then burning most of it to get some of it back up to orbit.

It's much better to just leave it in orbit in the first place. Or at least it *should* be...

Best,

-Slashy

[Superfluous J]

So to use your argument, it's better (or at least the same) to spend $1000 on fuel than it is to spend $100 on the same amount of fuel?

The above question assumes you can return $1000 worth of fuel for an investment of $100. At some point, I agree it is NOT worth it because you have to invest $100 + time and while for $100 the time is worth it, I'm not sure if it's worth it if it costs you $500. It's assuredly not worth it if it would cost you $900.

[ddenis]

Well... looking at it as a rational exercise, it kinda has to be that way.

When you recover your tank of fuel, they pay you (say) a thousand credits for it. Then you turn around and buy it right back for a thousand credits. It's like moving money from your left pocket to your right pocket; the transaction may as well not have happened.

So basically what you're doing is deorbiting your fuel, keeping it in a temporary fuel tank, putting it in another rocket, and then burning most of it to get some of it back up to orbit.

It's much better to just leave it in orbit in the first place. Or at least it *should* be...

Best,

-Slashy

Several things:

1) No one says that all produced fuel will be moved to KSC, it can be 50% or any other number.

2) Have you ever put money in bank? Yes, It's the same... "It's like moving money from your left pocket to your right pocket". Basicaly one can store money not in things, but in currency. Because there is no difference in selling/buying price if fuel recovered in KSC, then one could not bother with manual moving fuel through KSC. (But I really like that idea now and will use it in my 1.0. game, maybe.).

Edited April 26, 2015 by ddenis

[GoSlash27]

So to use your argument, it's better (or at least the same) to spend $1000 on fuel than it is to spend $100 on the same amount of fuel?

The above question assumes you can return $1000 worth of fuel for an investment of $100. At some point, I agree it is NOT worth it because you have to invest $100 + time and while for $100 the time is worth it, I'm not sure if it's worth it if it costs you $500. It's assuredly not worth it if it would cost you $900.

5thHorseman,

No, that's definitely not my argument. It's absolutely worth it to spend $100 for your fuel instead of $1000. That's why we're going to mine ore and process it in space. It's just not worth it to then deorbit the cheap fuel you've made and relaunch it.

ddenis,

Several things:

1) No one says that all produced fuel will be moved to KSC, it can be 50% or any other number.

2) Have you ever put money in bank? Yes, It's the same... "It's like moving money from your left pocket to your right pocket". Basicaly one can store money not in things, but in currency. Because there is no difference in selling/buying price if fuel recovered in KSC, then one could not bother with manual moving fuel through KSC. (But I really like that idea now and will use it in my 1.0. game, maybe.).

IRT point 1, I would argue that the ideal percentage would be zero.

Point 2, it is sorta like putting your money in a bank, but (to use your analogy) you have a choice in which bank you use. LKO National Bank allows you to make free cash withdrawals while KSC Credit Union hits you with heavy transaction fees for "drag and gravity well".

And it goes back to my original point; you won't ever turn a "profit" by putting your money in a savings account. At least one that doesn't pay interest. The best you can do is spend your money as wisely as possible.

Best,

-Slashy

[Superfluous J]

Okay I've bowed out already and been drawn back in. I'll (if it's possible and necessary) Spend $100 for every $1000 of fuel I can bring back to Kerbin and make cash hand over fist. You can spend $1000 on fuel and "save money" by not bringing the fuel down the gravity well to where you need it to launch. We're both good enough at the game that neither strategy will make or break our careers.

[GoSlash27]

Fair 'nuff. I'm not going to convince you if I'm right, and I'm not really certain I am anyway

But as long as you're getting into the business, I have an idea that I think will help:

There's no need to go to space to get cheap (or even free) fuel.

You could set up an oil field/ refinery on Kerbin and save yourself a whole lot of transportation/ infrastructure expenditure. It'd be pure (or nearly pure) profit.

Best,

-Slashy

[ddenis]

+1 to GoSlash27 about not going into space for mining at Kerbin.

TheWinterOwl has shown where ore can be found on Kerbin.

https://youtu.be/pX_QJuZoW70?t=52m8s

Assuming, that an ore map is persistant, and if it isn't, one can find another suited spot.

Edited April 26, 2015 by ddenis

[Alshain]

Okay I've bowed out already and been drawn back in. I'll (if it's possible and necessary) Spend $100 for every $1000 of fuel I can bring back to Kerbin and make cash hand over fist. You can spend $1000 on fuel and "save money" by not bringing the fuel down the gravity well to where you need it to launch. We're both good enough at the game that neither strategy will make or break our careers.

His point is you don't need to launch the fuel. Assuming you are going somewhere other than LKO, you use it to go there. If you are going to Duna, you have to...

1. Have enough fuel to lift the weight of the craft itself.

2. Have enough fuel to lift the fuel it takes to go to Duna.

3. Have the equilibrium fuel that it takes to lift the remaining ascent fuel in your ascent stage. (i.e. you have to lift fuel to 10km so you can burn it at 10km, you have to lift fuel to 20km so you can burn it at 20km, etc. until you reach orbit)

If you empty your Duna craft, i.e. little to no fuel and instead fuel it in orbit. #2 is removed from the equation entirely which makes #3 is far less than it was before because the craft is lighter, you don't need as much fuel to lift it and then you don't need as much fuel to lift THAT fuel. So by having all that fuel in orbit, you don't have to buy your fuel to go to Duna, and you don't have to buy as much to get to orbit. You win twice.

However, if you return it to the surface, you have to buy it and buy enough to lift it.

[Superfluous J]

Ah. I see the problem. You guys think I'm going to launch with enough fuel to get to Duna.

No. I wouldn't do that. I would launch with enough fuel to get to LKO, refuel there, and then go to Duna from there.

You only use the fuel you sent down to Kerbin to get up to LKO. I apologize, I thought that was obvious.

Honestly though I don't think it's worth all this effort, really. I expect that the game will be easy enough that just spending the money on fuel on the surface will be much better. Pay the money so you can spend your time doing fun stuff. The only real reason to go through the rigamarole is to enjoy having done it.

[Wjolcz]

OK, so I see some people misunderstood me.

I posted this thread and the idea of mining for Xenon ONLY before we knew the ISRU converter doesn't allow to produce it. The idea was:

1. Use LF/O to go places

2. Mine for ore and convert it into tons of Xenon

3. Go back

4. Sell Xenon

5. Get money for LF/O +extra cash

I DIDN'T mean recovering LF/O. I meant Recovering Xenon, because it has a way higher price than LF/O. But it's not possible : /

Edited April 26, 2015 by Veeltch

[Srpadget]

I don't understand the whole point of this thread.

1) LF/O, per se, both in-game and IRL, is basically FREE compared to the cost of everything else involved in running a space program. The whole point of resource mining is to avoid having to haul it from the homeworld's surface--which costs an enormous amount unless you've got efficient reusable SSTOs so you're not throwing away expensive single-use hardware. The whole argument of taking fuel back home *for profit* just boggles my mind. Might as well talk about mining ice on Eeloo and bringing back the water to sell at a profit.

2) I have not used Karbonite, Kethane, or (obviously) the new stock system. But ANY system that makes it profitable to haul ORE out of a gravity well in order to purify it on-orbit? Fundamentally flawed. What is the NUMBER-ONE rule of intelligent spacecraft design? (MOAR BOOSTERS!! MOAR STRUTS!!--Um, okay, fair point. I guess I mean the number-THREE rule...?) :-D Minimize EVERYTHING that isn't either essential payload or fuel. Ore (by whatever name it's called) is by definition unrefined...which means (again by definition) there's not-fuel crap in it. So to minimize mass-haulage, you transport the refinery (ONCE) down the gravity well, refine/process the raw material to a final product on the surface, and then take JUST the final fuel product back up to orbit.

2) Again, I have not used these mods...but I gather from commentary in this thread that Kethane's raw resource actually masses LESS than the amount of LF/O you can extract from it...? Erm...not to put too fine a point on it, but isn't this game supposed to be grounded in (mostly) realistic physics (at least as far as they impact rockets and orbits) [caveats re patched-conics inserted by reference]? My point here being: if a mod decides to toss out *conservation of mass* in the interest of gameplay, I myself would consider that an argument AGAINST, rather than an argument FOR, the mod's approach. And IF (third time: I haven't used Kethane myself and thus freely admit I don't know the facts), IF, Kethane processing generates a greater mass of LF/O than the mass of the raw Kethane you start with? Make no mistake, that's exactly what such a scheme would mean: tossing out that inconvenient "conservation of mass" business.

Sorry if this comes across as combative, or appears to be saying something unflattering about somebody's favorite mod. That's not my intent, really it's not. I'm just really uncomprehending why we've even got this thread, let alone why it's gone on for multiple pages.

[touzenesmy]

About conservation of mass, you know, 1L of oil =/= 1L of gaz.

Like in mods, 1 L of kethan =/= 1L of liquide fuel, for the obvious reason that you'll ever, never, get a 100% efficiency on a rafinery, and more than this, when you refine a product, you get a LOT of other products, and you sell them as separate products,

for example:

1L oil = % gaz, %unusable material, %plastic, ...etc

And because we only need LO/MONO/..etc ressources in kerbal, refineries won't give you the usual materials extracted in real life.

Sorry for my english btw

[Alshain]

OK, so I see some people misunderstood me.

I posted this thread and the idea of mining for Xenon ONLY before we knew the ISRU converter doesn't allow to produce it. The idea was:

1. Use LF/O to go places

2. Mine for ore and convert it into tons of Xenon

3. Go back

4. Sell Xenon

5. Get money for LF/O +extra cash

I DIDN'T mean recovering LF/O. I meant Recovering Xenon, because it has a way higher price than LF/O. But it's not possible : /

Well, we understood you but after it was determined that the ISRU wouldn't convert to Xenon, the thread kinda veered off in another directions.

That has a tendancy to happen after the thread has been marked answered. People like to discuss other possibilities.

[GoSlash27]

I don't understand the whole point of this thread...

Point #1 I fully agree. Points 2 and 2b, I also agree there, but I don't think that was ever central to it.

Best,

-Slashy