Scott Manley weighed in on the Nuke discussion - what do you think?

[ShadowZone]

you can watch it here:

Althugh it's a great explanation, I have a point of contention: The problem is not the way the engine works now but the options players have how to implement it. Why? There are not enough variants of liquid fuel only tanks in the game. Take the Mk3 line of parts: Instead of 2500 units of LF the standard Mk3 tank parts offer only 1125 units of LF. So the efficiency of the Nuke is reduced as soon as you need to use other tanks than the pure LF parts. And if you want to give your ships some curves (as I like to do) you need the adapter parts - and those are only available as LFO. I regard this as an oversight that could be easily remedied by the developers.

The way things are in stock, you get less dV per part or regarding the size of the vessel. If we stick with the short Mk3 tank, the LF only variant gets >10.000 dV with one nuke, the LFO variante with oxidizer emptied gets us barely >6000. That is a HUGE difference! If you increase the amount of engines, the ratio gets even worse. So yes, the Nuke is now less desirable to use. But in my opinion this could be fixed with tweakable tanks (at least with the Mk3 and/or adapter parts) or more LF tank parts.

I just did the math: I have a 245 ton interplanetary exploration vessel (with multiple landers and probes). It clocks in at around 2000 dV with the parts as they are. If those LFO tanks I had to use had pure LF variants, vehicle mass would increase to 290 tons, but dV would rise above 3000. So once again: the problem isn't the behavior of the LV-N, it is the options players have how they can use it. The vehicle is still more efficient with nukes than with any other chemical rocket. However, it could still be a lot better if the developers would give us more tank options for LF only.

[SpaceChipmunk]

It is a pain, but I am sure the developers will add more LF only variants. If not, there's a mod for that.

[Vaporo]

Yeah, there really should be more pure LF tanks. Maybe do what B9 aerospace (through the firespitter mod?) does and have multiple tweakable versions of each tank, some with a different texure/model.

[Col_Jessep]

Having a switch between liquid fuel and oxidizer would be nice for building planes, too!

[Xannari Ferrows]

I'm gonna get around to making my own liquid hydrogen fuel, and giving the Nuclear engine a MultiMode engine module.

[rtxoff]

It's really easy to add this tanks by yourself if you need them however i agree that the best solution would be to implement tweakable fuels into the stock game. So you would be able to use every fuel in every tank.

Also as far as i remember there was already a mod for this not sure if it is updated though.

[Skorpychan]

This looks like a job for the modding community, at least until the devs get on with releasing a fix.

Could just use the same skins and textures as stock, and just edit the contents and name.

[pandaman]

To me it makes sense to have tanks in the editor as empty shells to save on part types. When you click on a tank to select it you get a 'select fuel type' pop up windows which then permanently configures the tank and applies the relevant colour bands to the texture.

[rtxoff]

Ok i've found the mod and it is updated: http://forum.kerbalspaceprogram.com/threads/64117

[Murph]

Althugh it's a great explanation, I have a point of contention: The problem is not the way the engine works now but the options players have how to implement it. Why? There are not enough variants of liquid fuel only tanks in the game. Take the Mk3 line of parts: Instead of 2500 units of LF the standard Mk3 tank parts offer only 1125 units of LF. So the efficiency of the Nuke is reduced as soon as you need to use other tanks than the pure LF parts. And if you want to give your ships some curves (as I like to do) you need the adapter parts - and those are only available as LFO. I regard this as an oversight that could be easily remedied by the developers.

The way things are in stock, you get less dV per part or regarding the size of the vessel. If we stick with the short Mk3 tank, the LF only variant gets >10.000 dV with one nuke, the LFO variante with oxidizer emptied gets us barely >6000. That is a HUGE difference! If you increase the amount of engines, the ratio gets even worse. So yes, the Nuke is now less desirable to use. But in my opinion this could be fixed with tweakable tanks (at least with the Mk3 and/or adapter parts) or more LF tank parts.

I just did the math: I have a 245 ton interplanetary exploration vessel (with multiple landers and probes). It clocks in at around 2000 dV with the parts as they are. If those LFO tanks I had to use had pure LF variants, vehicle mass would increase to 290 tons, but dV would rise above 3000. So once again: the problem isn't the behavior of the LV-N, it is the options players have how they can use it. The vehicle is still more efficient with nukes than with any other chemical rocket. However, it could still be a lot better if the developers would give us more tank options for LF only.

The way I interpret Scott, and I agree with him, is that he's saying that you're actually getting a more than fair deal when you use a LF+O tank with no O in it, combined with the LV-N. Taking the LF to be Kerosene/RP-1, which makes sense for it being a common fuel for both rocket and jet engines, the fuel quantity when you use a LF+O tank with no O for the LV-N is better than if you had the correct LH tank for the LV-N. In reality, the LV-N can't actually run on KSP's LF it has to use LH. LH needs bigger tanks, and it's a more than fair equivalence when you emulate that with a LF+O tank with the O half empty.

Ignore the fact the tanks are LF+O, and pretend that they magically become LH when configured as 100% LF + 0% O. If you do that, everything is fine, there is no real problem, and we don't even need more tank choice.

[SelectHalfling0]

I agree. Quick! Get this thread popular so Squad sees!!

Community Assemble!

[Yukon0009]

I approve and agree.

Support.

[Whirligig Girl]

I agree.

[Roflcopterkklol]

I do kinda have beef with the new version loving huge craft, you have to make craft large if you want performance which is fine because i love large craft but most people don't have great PC's, i feel sorry for them missing out on a lot of the game because of it.

This thing for an example, to get that 5000m/s of delta V once in a 100km orbit it takes well... look at the part count and mass.

[Levelord]

I am more concerned with the NERVA engines overheating when it's not supposed to because you have cryogenic fuel cooling the reactor down in the first place. The engine is only supposed to overheat when you run out of fuel to cool down the unit.

[Murph]

Yup, Squad, pay attention. Scott seems to be basically saying that there isn't any real problem with the LV-N, and we do not actually need any new tankage. Or, if you're going to change anything, introduce liquid hydrogen as a fuel type, with a whole new line of LH-only tanks that are much larger, and make the LV-N LH only (and correspondingly physically HUGE low density tanks, which I'd bet very few people would like).

I agree with him. I was 99% sure there wasn't a real problem before, seeing that video has pushed me to 100% convinced that what we have today is actually quite ok, and there is no serious problem with either the LV-N, or using LF+O tanks with it. It is a perfectly reasonable approximation as-is.

Well done, Squad, you got it right, and there's no real need for change! (Edit: although the thermal issues should probably still be seriously thought about, I'm only talking about LV-N and tanks there.)

[ShadowZone]

The way I interpret Scott, and I agree with him, is that he's saying that you're actually getting a more than fair deal when you use a LF+O tank with no O in it, combined with the LV-N. Taking the LF to be Kerosene/RP-1, which makes sense for it being a common fuel for both rocket and jet engines, the fuel quantity when you use a LF+O tank with no O for the LV-N is better than if you had the correct LH tank for the LV-N. In reality, the LV-N can't actually run on KSP's LF it has to use LH. LH needs bigger tanks, and it's a more than fair equivalence when you emulate that with a LF+O tank with the O half empty.

Ignore the fact the tanks are LF+O, and pretend that they magically become LH when configured as 100% LF + 0% O. If you do that, everything is fine, there is no real problem, and we don't even need more tank choice.

but then the pure LF tanks are the odd ones out. if you argue that you should use LFO tanks without O in combination with a LV-N, then it should not be possible to use the LV-N with pure LF tanks.

I could really live with the "LFO tanks only, but no O" restriction, but not with the "yeah, you can use pure LF tanks, but no we don't give you any" situation as it remains.

[brdavis]

Yup, Squad, pay attention. Scott seems to be basically saying that there isn't any real problem with the LV-N, and we do not actually need any new tankage.

Agreed. LH is annoying stuff to work with - low density, cryogenic, etc. If you want a 'realistic' fuel for a KSP NERVA… then those tanks aren't oversized. Probably undersized.

[Murph]

but then the pure LF tanks are the odd ones out. if you argue that you should use LFO tanks without O in combination with a LV-N, then it should not be possible to use the LV-N with pure LF tanks.

I could really live with the "LFO tanks only, but no O" restriction, but not with the "yeah, you can use pure LF tanks, but no we don't give you any" situation as it remains.

Well, you're not being given any as you don't actually need them, and there isn't an equivalence in reality for them. You can cheat and use plane tanks to create an unrealistically small LV-N rocket, or you can use LF+O (with 0% O) for something getting closer to reality. They are not a perfect equivalence, most likely actually being too high density, but are closer to the truth. (For me, cheating in this type of game includes any time you do something which is known to have a fundamental conflict with reality. But, there's actually nothing wrong with cheating in this type of game, define your personal rules as you see fit. If realism is important, never use the current LF-only tanks with the LV-N.)

Pure LF-only tanks are very much needed for the jets and RAPIER in air mode, and realistic for those purposes. They just shouldn't really be used for the LV-N.

[Warzouz]

LV-N have been nerfed, there were too op in the past.

I kind of like that, because the LV-N is not the only reasonable way to go for interplanetary anymore. I'm rediscovering other engines and I'm using a much broader set of engines now.

I find that much more interesting.

But Squad should work on Rockamax fuel size LF-only tanks and better bi/tri/quad coupler management.

[ShadowZone]

Well, you're not being given any as you don't actually need them, and there isn't an equivalence in reality for them. You can cheat and use plane tanks to create an unrealistically small LV-N rocket, or you can use LF+O (with 0% O) for something getting closer to reality. They are not a perfect equivalence, most likely actually being too high density, but are closer to the truth. (For me, cheating in this type of game includes any time you do something which is known to have a fundamental conflict with reality. But, there's actually nothing wrong with cheating in this type of game, define your personal rules as you see fit. If realism is important, never use the current LF-only tanks with the LV-N.)

Pure LF-only tanks are very much needed for the jets and RAPIER in air mode, and realistic for those purposes. They just shouldn't really be used for the LV-N.

I am sorry but I have to disagree. If the game defines "LV-N uses the same LF as any other engine" then it's not cheating using pure LF tanks. And regarding small: The Mk3 short tank weighs 14,29 tons, more than entire airplanes and carries either 1125/1375 LFO or 2500 LF. So why would you regard it as cheating using such tanks? And if there are two variants of the Mk3 "block" tanks and the Mk2 straight tanks, why aren't there the same variants for the adapter parts? It is just illogical.

If the devs wanted to restrict the LV-N to LFO tanks without O, then they should have made such a restriction. For instance "needs 1 unit of O to ignite but doesn't consume it" would be a very straightforward but not too complicated from a gameplay standpoint.

But such a rule is not in effect, so I stand by my statement: either introduce such a restriction or give us more LF tank options.

[Roderik]

i'm glad i watched it! now i know i can make smaller rockets with more delta-v instead of one huge rocket just to get a lot of delta-v

[arq]

Given the presence of spaceplane parts, the LF-minus-O tanks are a terrible balance 'solution' to the LV-N. If the LV-N needs to be brought in line then it needs less ISP (maybe set it to 600s) or a dedicated fuel type to make it consistent, and if it doesn't then we need tweakable fuel types in tanks in the stock game (and those would be welcome regardless).

In the meantime, tweakable fuel types are also available through http://forum.kerbalspaceprogram.com/threads/121321-Stock-Fuel-Switch. This mod can supposedly be uninstalled without breaking stuff if this feature ever becomes stock.

[Murph]

I am sorry but I have to disagree. If the game defines "LV-N uses the same LF as any other engine" then it's not cheating using pure LF tanks. And regarding small: The Mk3 short tank weighs 14,29 tons, more than entire airplanes and carries either 1125/1375 LFO or 2500 LF. So why would you regard it as cheating using such tanks? And if there are two variants of the Mk3 "block" tanks and the Mk2 straight tanks, why aren't there the same variants for the adapter parts? It is just illogical.

If the devs wanted to restrict the LV-N to LFO tanks without O, then they should have made such a restriction. For instance "needs 1 unit of O to ignite but doesn't consume it" would be a very straightforward but not too complicated from a gameplay standpoint.

But such a rule is not in effect, so I stand by my statement: either introduce such a restriction or give us more LF tank options.

I stand by my previous statements. It is irrelevant what is possible in the game, only what is realistic. It is unrealistic to use the LF-only tanks with the LV-N, as the fuel density is far too high. That is the only necessary factor to make me consider it to be cheating to use them with it. It is a hack by the game, to avoid introducing another fuel type, and is quite clearly balance around using LF+O tanks with the O part empty. I don't need the devs to handcuff me in choices, I'm quite capable of recognising that it's very unrealistic to use the LF-only tanks with the LV-N, now that I have reviewed the evidence.

We absolutely do not need more LF-only tank options, as they would push the LV-N towards being overpowered. It is just fine as-is, used with LF+O tanks. There is no problem to solve, it is not broken, nothing needs urgently fixed.

Squad, please DO NOT give us any new LF-only tanks for the LV-N, they are not in any way needed.

[Joonatan1998]

I stand by my previous statements. It is irrelevant what is possible in the game, only what is realistic. It is unrealistic to use the LF-only tanks with the LV-N, as the fuel density is far too high. That is the only necessary factor to make me consider it to be cheating to use them with it. It is a hack by the game, to avoid introducing another fuel type, and is quite clearly balance around using LF+O tanks with the O part empty. I don't need the devs to handcuff me in choices, I'm quite capable of recognising that it's very unrealistic to use the LF-only tanks with the LV-N, now that I have reviewed the evidence.

We absolutely do not need more LF-only tank options, as they would push the LV-N towards being overpowered. It is just fine as-is, used with LF+O tanks. There is no problem to solve, it is not broken, nothing needs urgently fixed.

Squad, please DO NOT give us any new LF-only tanks for the LV-N, they are not in any way needed.

Are reaction wheels cheating too?

They are a lot more unrealistic than a bit too dense fuel.