Ore is Overpowered

[arq]

EDIT: With the release of 1.0.1, ore tanks now have the same mass fraction as fuel tanks. This discussion is no longer relevant.

I expect this may be nerfed in a future version, and correct me if I'm mistaken, but with the release of 1.0:

The new ore tanks are overpowered. Not because you can refill them by mining (that's the idea, right?), but because they have a higher fuel fraction than other fuel tanks. This means that it is cheaper (dV-wise) to carry ore than it is LFO (liquid fuel/oxidizer).

Ore masses 10kg/unit and LFO masses 5kg per unit. The ISRU converts 1 Ore to 2 LFO, so the mass conversion ratio is 1:1. LFO tanks have a dry fraction of 1/9 (they hold 8kg of fuel for every 1kg of tank), or less for some parts. However, the ore holding tanks have a mass fraction of 1/12 for the small tank and 1/15 for the large tank. In other words, using large tanks you can store ore 67% more efficiently than you can store LFO. The mass of the ISRU and solar panels (or fuel cells), lets round that up to 5t (assuming you didn't have them already), offsets this a bit. But by the time you want around 200k LFO (100t, along with 12.5t of tank) or more, it is actually lighter to carry that mass in ore along with an ISRU and convert it along the way (carrying just enough of the heavier LFO tanks to hold the fuel before it is burned).

Now this has some issues. One requires 1.7 ISRU's to continuously feed a single LV-N engine. To make the break-even point your *average* (see the next paragraph) acceleration will be around 0.3m/s at best (though it will improve as fuel is spent), or a TWR of 0.03, meaning it will take close to an hour of burning (over 20+ orbits, most likely) to transfer to Mun from Kerbin.

This can be offset by having a slightly larger reserve of LFO so that you can convert it slowly and spend it in bursts. Most maneuvers in LKO last 5 minutes or less (beyond this you can't make Oberth-efficient maneuvers), so stocking ~400 fuel per LV-N should allow this and cost only 0.1t extra per LV-N (you were already paying 0.15t for 200 units of ore tank, so you just pay the difference for the LFO tank). A single ISRU provides enough fuel for at least 18 engine-minutes of LV-N thrust per orbit of Kerbin (and much more at longer, higher orbits), so now you can use 4 (or more) LV-N's to achieve a modest (but playable, for the patient) burst TWR of 0.2. But remember that you'll be in shadow for half that time (when in low orbits) so you'll need extra solar power to compensate (or just use fuel cells, or expect shorter burns until you get to high enough orbits to have enough time to fuel longer ones).

Should you do this for every large ship? Not unless you are willing to make long burns. But for fueling stations (or ships that already carry an ISRU), you should store as much fuel as ore possible. Suppose a 200t LFO-only ship has mass ratios 160:20:20 for fuel:tank:misc (where misc is engines, capsules, payload, etc) and a 200t ore-based ship has a ratio of 168:12:25 for ore:tank:misc (misc now includes an ISRU). The ore ship will have 9% more dV for the same payload and TWR while possessing an ISRU (or one could remove fuel to have equal dV while being 12% lighter, offering easier launching and higher TWR).

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As an added bonus, the ore tanks have a smaller form-factor (the 1500 unit large holding tank holds almost as much fuel as the 3200 unit LFO tank yet is half the size) and ore is basically free (500kg/cred vs 11kg/cred for LFO), though the size and cost of the ISRU and extra power offsets some of this. Also, by cost it is cheaper to convert all your LFO on the pad and recover the ISRU than to buy the fuel in the VAB.

Edited May 1, 2015 by arq
1.0.1 update

[Khobai]

I noticed this too. Ore is significantly lighter than Fuel. And converting ore to fuel only requires a 4 ton piece of equipment.

An easy fix would be simply to not allow people to fill their tanks with ore in the VAB/SPH. The only way to get ore should be from mining.

[SaturnV]

From your data and analysis, I take it “ore is a good alternative for large toys“ rather than “overpowered“?

[Whackjob]

Sounds like ore needs to be significantly heavier.

[Renegrade]

Why not just reduce the mass ratios of the ore tanks? Problem solved, even for people launching ore-tanker ships from the launchpad...

Top those puppies out at 7:1 and nobody would cart raw ore around unless they were forced to. Isn't the general karbonite design to refine on the surface and ship finished product only? "Ore" implies lots of impurities too, it really should not be a 1:1 mass conversion..

(anyhow KSP should really disassociate itself from these imaginary units. A kilogram of something is always a kilogram of something. A liter or cubic decimeter of something depends on it's temperature and pressure and whether or not it's tuesday or if it's offended by the tank's paint job..)

[Whirligig Girl]

Ore needs to be made heavier and more expensive than fuel. Specifically, I want to be able to bring ore back from space and sell it for a good price. And I think ISRU modules should be more efficient to use on stations and surface bases, rather than landers.

- - - Updated - - -

Why not just reduce the mass ratios of the ore tanks? Problem solved, even for people launching ore-tanker ships from the launchpad...

Top those puppies out at 7:1 and nobody would cart raw ore around unless they were forced to. Isn't the general karbonite design to refine on the surface and ship finished product only? "Ore" implies lots of impurities too, it really should not be a 1:1 mass conversion..

(anyhow KSP should really disassociate itself from these imaginary units. A kilogram of something is always a kilogram of something. A liter or cubic decimeter of something depends on it's temperature and pressure and whether or not it's tuesday or if it's offended by the tank's paint job..)

I completely agree. KSP's fuel system needs to be better standardized.

[Khobai]

Because carting around ore should be an option. If you make ore worse than fuel than carting around ore is pointless.

I think if you go through the trouble of mining ore on other planets it should have some benefit over regular fuel.

The main problem that I see is you can launch ships with full ore tanks from VAB/SPH. So youre getting the reward of mining without doing the work.

[Renegrade]

Because carting around ore should be an option. If you make ore worse than fuel than carting around ore is pointless.

I think if you go through the trouble of mining ore on other planets it should have some benefit over regular fuel.

Why?

Why should it have some benefit over regular fuel? You can ALREADY get it from non-launchpad places, which is a TREMENDOUS advantage.. it doesn't need more.

[LadyAthena]

I think allowing you to grab Ore in the VAB was an over sight.. I really doubt they meant for you to be able to do that, as it completely kills the point of mining...

[WanderingKid]

Have you tried using the ISRU Converter? The thing overheats like mad, particularly on Kerbin (working on getting a full rig to Mun). Once we get heat radiators figured out it might be more useful but for the moment I overheated it creating 12 fuel and it's associated oxidizer. You couldn't even hope to convert fuel -> usable material at a useful rate, you'll have to bring along sizable empty storage tanks for the LF+O between 'hops'.

The only plus side it has is that it'll run while you're not watching it at something like 0.51% Load.

Edit: I should add it's an electricity hog as well. I've sustained Ion Engines easier.

Edited April 28, 2015 by WanderingKid

[Joonatan1998]

You can buy ore from VAB?

Doesn't that create an exploit, where you buy a ton of ore, the process it on the launch pad, then recover.

We don't even have to mine on the launch pad...

(if it truly is unusable because of overheating, that might help.)

[WanderingKid]

Tweak the ore container and fill it with ore, you now have ore. Similar to emptying a fuel tank, just in reverse.

[DevoidLight]

Making Ore heavier seems like a better suggestion, we should still be able to pre-fill tanks with Ore for testing purposes I think.

[T-Bouw]

I endorse making Ore heavier!

In real-life, ore is always heavier than the product it gets turned into.

There're always losses incurred during the refining process. Impurities, etc.

You can't create more from less (sadly:).

[Temeter]

All of these changes seem to be changes for the sake of it. Why shouldn't we be able to move ore around, what is the gain by making it heavier? Atm it seems to me that it's only about taking away gameplay options. Maybe ore is a tiny bit more storage efficient, but that will be more than negated by ISRU and electricity equipment weight anyway. Could be changed by a tiny tweak and nobody would even notice it during normal gameplay.

Btw: Selling expensive ore is a neat idea, but won't work as long as you can mine on kerbin.

Edited April 28, 2015 by Temeter

[LN400]

Dunno, seems to me the main idea of mining/ore is that you can set up refueling stations on other planets, rather than building up a trading empire. Then, having heavier/cheaper ore makes sense, gameplay wise as well as in general. Ore, I would think, is heavier than fuel and a whole lot cheaper. A refueling station on other planets would make it more than worthwhile. You can even set up an orbital refueling station with drone rockets shuttling back and forth between the drilling operation and the station. The gain there far outweights any loss in not being able to directly profit from it.

[uglyduckling81]

I like the idea of making Ore valuable and sellable on Kerbin.

Getting large amounts of ore home to sell on the open market as another option to make cash other than just contracts.

[mattinoz]

I think it makes sense the tanks are lighter they are after all much simpler. They aren't trying to keep a liquid liquid against the inky cold blackness of space while the sun beats down on them.

What does seem over powered like other have said is that 1kg of Ore turns in to 1kg of fuel. Not to over complicate it but it should be much lower conversion rate with the remaining mass dumped out the side of unit. Maybe future mods could capture this waste/dust and turn it in something useful but to me there really should be some waste output from the system even if it doesn't render.

[Technical Ben]

It should be heavier. Cheaper yes, but heavier.

[arq]

The fundamental issue at play here is that ore tanks are a lighter method of storing (unconverted) LFO than LFO tanks. A nerf to ore tanks or to conversion efficiency would solve this. I'm okay with the idea of drills 'discarding' the slag material and just storing the pure LFO ingredients, allowing a very high conversion efficiency. After all, conservation of mass and whatnot. But the ore tanks need to be heavier to discourage what was described in the OP.

I would say that a reasonable solution would be to increase the dry fraction of ore tanks to 1/9, like LFO tanks, and reduce conversion efficiency to 80-90%. Or to leave them at 1/15 and reduce efficiency to 50%. Then players are incentivized to convert ore at the earliest opportunity, because it will be lighter as LFO, and this removes the exploit of the ISRU as a range extender. The ISRU would still be useful for its ability to process fuel mined along the way - which I perceive was the original intent.

[Jarin]

Isn't this the same debate we had a while back regarding Kethane vs. Karbonite? The former was light enough to make it efficient to haul the raw resource to an orbital refinery, while the latter is heavier and must be processed in place. Seems that stock is currently balanced a bit closer to the former, or at least in the middle.

[Khobai]

Why shouldnt ore tanks be lighter though? Ore isnt volatile like fuel and doesnt need cryogenic systems to keep it stable. Its much easier to store ore than it is to store fuel. An inflatable storage container would work fine and weigh almost nothing.

I agree that Ore needs a nerf. But I dont agree with people that want to take the fun out of having to transport ore to orbital refineries.

I personally think the ISRU is what needs a nerf. 4 tons is way too light and makes it way too easy to put on a lander. Also you shouldnt be able to fill up your ore tanks at KSP.

Why?

Why should it have some benefit over regular fuel? You can ALREADY get it from non-launchpad places, which is a TREMENDOUS advantage.. it doesn't need more.

Because sending down a lander with a drill, ISRU, single ore tank, and huge fuel tank is BORING. Theres NO challenge in that.

But if refining has to be done in orbit then you have to send a lander down with multiple ore tanks and transport it back to the refinery. Thats more challenging and rewarding IMO.

[vixr]

why shouldnt ore tanks be lighter though? Ore isnt volatile like fuel and doesnt need cryogenic systems to keep it stable. Its much easier to store ore than it is to store fuel. An inflatable storage container would work fine and weigh almost nothing.

I agree that ore needs a nerf. But i dont agree with people that want to take the fun out of having to transport ore to orbital refineries.

I personally think the isru is what needs a nerf. 4 tons is way too light and makes it way too easy to put on a lander. Also you shouldnt be able to fill up your ore tanks at ksp.

Because sending down a lander with a drill, isru, single ore tank, and huge fuel tank is boring. Theres no challenge in that.

But if refining has to be done in orbit then you have to send a lander down with multiple ore tanks and transport it back to the refinery. Thats more challenging and rewarding imo.

^this^

[RoverDude]

Hopping in

Ore tweaking in the VAB is not an oversight. That is by design because players need to easily be able to test out mining and conversion rig designs.

Ore is not lighter than fuel - it's mass neutral. This is also by design due to the impact of a lossy conversion on other systems. No conservation of mass rules were violated in the creation of this feature.

I concur with the assessment that the tank mass should be adjusted to match corresponding LFO tanks (they are all at 89.99 as I recall). At that point, there is no mass benefit, only a resource density benefit (but heavier tanks offset this).

Beyond that - if you wish to make an Ore ship, rock on you will have to pay a tax for the ISRU module and it's power requirements, but that will be a lot less appealing if the tank mass ratio benefit is removed (see above).

Orbital and ground based refineries are equally viable because of Ore being mass neutral. Really boils down to playstyle, and I am ok with that (personally I will be doing ground refineries in my own save).

Ore is not overly valuable, it was not meant as a funds faucet - it's cheap as dirt. I expect mods will quickly fill the gap for people looking to use ISRU as funds generation. About the best you could do... in theory... is build a massive mining rig to convert Ore into LF (which is the most profitable of the potential products).

Given the work involved, and how far down the tech tree ISRU is, funds are not much of an issue that late in the game. But if someone wishes to play Kerbal Fuel Refinery Program, then by all means rock on and have fun with the legos

[Khobai]

I concur with the assessment that the tank mass should be adjusted to match corresponding LFO tanks (they are all at 89.99 as I recall). At that point, there is no mass benefit, only a resource density benefit (but heavier tanks offset this).

Again that kills the whole concept of orbital refineries... unless ore is lighter than fuel then lifting ore off the surface is a pointless endeavor.

I still believe the problem is the ISRU weighing only 4 tons. 4 tons is just not a reasonable weight.

The ISRU has to process ore, capture expelled water and CO2, convert the water to hydrogen and the CO2 to oxygen, convert the *highly flammable* hydrogen to a more stable cryogenic liquid fuel, all while avoiding the catastrophe of a hydrogen explosion, and withstanding the rigors of space travel. There's no way something that does all that is going to only weigh 4 tons. 10-15 tons is far more reasonable even with the consideration that kerbal technology is far more advanced than our own.

Even from a game balance perspective, ignoring any notions of realism, 4 tons just isnt balanced. It makes mining ore way too easy mode since all but the tiniest landers can carry an ISRU and reap huge benefits for almost no cost.

Edited April 29, 2015 by Khobai