[0.90]Kerbal Isp Difficulty Scaler v1.4.2; 12/16/14

[MAKC]

You might need to blanket increase engine thrust as well because right now we are carrying up more fuel with the same thrust as before.

[NathanKell]

Nope, that means you need more engines.

ferram: yeah, that's what I figured. And yeah, saw that code when I looked at the source when you released it. I'll push an update and give you the interface. Re: hybrid, it's done by forcing the module to reload from confignode, not creating a new module. So the pointer would still be the same and your code wouldn't trip, I think...

[CoriW]

So I feel like this plugin is going to make an Eve landing and return literally impossible. Awesome.

[Hodo]

It tries to fix the fact that KSP rockets to LKO average 15% payload, whereas you'd be lucky to break 1% in real life. The Ariane V is amazing at 2%. It's because Kerbin requires less than half the deltaV to reach orbit that Earth does, and deltaV has an exponential relationship with rocket mass (Tsiolkovsky's rocket equation).

KIDS? You know, the little folks who'll carry on the human race?

Oh you mean unfinished people.

Farram4, I had Arcturas Thrust corrector for a while, it is great, but has one minor problem. The SABRE engines don't calculate properly when switched over from air breathing to rocket, they lose more than 66% of their power no matter the altitude.

My first few SSTO/Space planes were designed with Thrust Corrector, FAR and DRE. It made getting to space a REAL challenge, let alone go to the Mun or Duna.

Edited October 16, 2013 by Hodo

[MAKC]

Nope, that means you need more engines.

ferram: yeah, that's what I figured. And yeah, saw that code when I looked at the source when you released it. I'll push an update and give you the interface. Re: hybrid, it's done by forcing the module to reload from confignode, not creating a new module. So the pointer would still be the same and your code wouldn't trip, I think...

You can only fit so many engines on a fueltank. It's still a problem.

[CoriW]

Right so I've actually gotten around to trying this now... And I love it.

I have yet to actually be able to get even a pod into orbit, and I'm using a lifter that could previously get something pretty much anywhere in the Kerbol system. Normally I would be rather frustrated by that, however because it's replicating real life it simply makes it an enjoyable challenge. Well done!

EDIT: My only disappointment is that the TWR on Kerbal Engineer and MechJeb are wrong. It's making it mighty troublesome to get the TWR right.

Edited October 16, 2013 by CoriW

[NathanKell]

How's the TWR wrong? Changing Isp shouldn't make a difference.

[MAKC]

How's the TWR wrong? Changing Isp shouldn't make a difference.

Lower Isp = more fuel needed for the same velocity change (in KSP anyway) = need to carry more fuel. With more fuel you get more weight but the engines don't scale since they're balanced for stock Isp values.

Edited October 16, 2013 by MAKC

[NathanKell]

They're not "balanced" for stock Isp values. That's really the point of this whole thread. CorlW said the TWR was displayed wrong. I asked wrong how. I didn't ask whether you felt your engines should somehow give you more thrust to make it easier--this _whole mod_ is about making it _harder_.

[Guest]

C7 indicated that he's willing to change the way Isp works. It might end up affecting thrust instead of fuel consumption at some point in the future. Then we're going to have TWR issues.

[MAKC]

They're not "balanced" for stock Isp values. That's really the point of this whole thread. CorlW said the TWR was displayed wrong. I asked wrong how. I didn't ask whether you felt your engines should somehow give you more thrust to make it easier--this _whole mod_ is about making it _harder_.

Realistic doesn't mean harder tho.

[NathanKell]

Yup. Realistic means 3-3.5km/s to orbit from Kerbin, tanks that are much lighter, and engines with about 5x the TWR. Want that? This whole dang thing is half about all the people complaining that realistic is too _easy_, that FAR makes it too darn easy to get to orbit. And you want realistic TWR on top of that?

If you want Earth-realistic, it means 9-9.6km/s to orbit, but still those other changes. Or you can use the "adjusted" values in this mod, rather than "raw real", which fakes those changes by cutting Isp in less than half to simulate how KSP mass ratios are screwy.

Dragon01: MFSC does this, as does Arcturus. And I already released a patch for MJ, at least, so the TWR is shown correctly.

[Guest]

I know about MFSC. Some day, I'm gonna set up a game with MFSC, FAR, Deadly Reentry, Ioncross, and a bunch of historical assets. Now, if there only was a way to make Kerbin bigger...

I hope that some day, there will be a way to ramp up KSP realism to near-Orbiter levels. Of course, that'd be an option only for the most hardcore players, but I think it could be fun. Remember, while Orbiter is a great sim, it doesn't have any ship construction features, and modding it isn't that easy. Of course, not many would use this, but remember, there are going to be some people who did a single-stage Eve mission and colonized Jool with stock values. We can't have them moving away from KSP, can't we?

[NathanKell]

My aim in life is that, basically.

[CoriW]

Sorry if I was incorrect, at the time of my posting that I was just confused as to why when Kerbal Engineer said my TWR was >1 my rocket couldn't lift it's own weight. I didn't mean to offend anybody but I've always thought >1 TWR meant it could lift it's own weight.

Actually now that I type that I can see where the confusion is coming from... While in the VAB Kerbal Engineer says my TWR is like 2+ and when I actually get out onto the pad it says like 0.9 or something, that's what I was referring to when I said "wrong".

[NathanKell]

Are you using a thrust corrector (either Arcturus or my own)?

Because that really shouldn't happen.

[CoriW]

Are you using a thrust corrector (either Arcturus or my own)?

Because that really shouldn't happen.

Wait a second... Thrust Corrector is what's breaking it in the VAB...? *sigh* I didn't even think of that.

Also... I'm currently using Arcturus, but you have a thrust corrector? Link? Does it work the same as Arcturus? I very well may switch to it because Arcturus still says it's for 0.20

[NathanKell]

The latest version of Modular Fuels has one. And I included, in the MFSC thread in sig, a modified MJ2 DLL that works with thrust correciton. asmi asked me to make one for KER, so I'm going to do that too.

Ferram and I are working on compatibility for this (Isp Scalar) with MFS; I need to implement a hook on my end, which I haven't done yet today. I plan to finish it this evening.

[White Owl]

Yeah, I played around with KIDS and the Arcturus Thrust Corrector a little bit. Kerbal Engineer definitely chokes on that combo; doesn't know how to read it. In that setup KIDS chops all your thrust in half, but everything still weighs more than real-life rockets... using stock engines and tanks I could barely get off the ground, let alone think about orbiting something.

I don't think KIDS + ATC + stock equipment will be a viable setup. But I still haven't looked at modular fuels, so maybe that could work.

[ferram4]

Looking more closely at Arcturus' source code, it looks like the only way for KIDS to properly function with it is for KIDS to load then Arcturus to load; the opposite will lead to engines making much, much less thrust, even in orbit (which might be the source of CoriW's problems). With that in mind, I'm going to implement an Isp-thrust-corrector feature in KIDS so that the order of operations can be handled properly. I'll also add an option to choose whether the rated thrust is for vacuum or sea level (with a selectable vac Isp cutoff for each one, i.e. vac Isp >380, rated thrust = thrust in vac, vac Isp <380, rated thrust = thrust at sea level). That should help with the lower thrust problems.

@MAKC: If you'd like that, do this using ModuleManager:

Go through each fuel tank, cut the dry mass in half and add that back in fuel mass.

For each engine, cut engine mass in half, multiply engine thrust by ~1.5.

Everything else should be about right where it is.

Use real life raw.

I'm not coding in any boosts to engine thrust (other than the pressure they're rated at) primarily because that strikes me as more of a design problem than anything else; you can always surface attach fuel tanks to the bottom of a stack and use fuel lines to make sure that they keep firing if you need more engines.

[CoriW]

Hey ferram, thanks for looking into that. Does that mean that it shouldn't actually be taking this to get a single 1 man command pod into orbit?

[ferram4]

Well, it depends on what setting you're using, but you shouldn't need 5 mainsails and 4 big SRBs to get going. O_O For context, I have a Soyuz-U style rocket that puts a Soyuz-like thing in orbit with the FAR to Real Life, Adjusted. There are 5 mainsails at the bottom, each moving ~2.5 orange tanks of fuel, so much, much more than you've got going on.

Thanks for confirming that Arcturus is incompatible to the extreme with this. I'll add my version of the thrust corrector post-haste with some code to detect if Arcturus is installed and to inform the user of the incompatibility so that other people don't have to suffer.

[CoriW]

Well, it depends on what setting you're using, but you shouldn't need 5 mainsails and 4 big SRBs to get going. O_O For context, I have a Soyuz-U style rocket that puts a Soyuz-like thing in orbit with the FAR to Real Life, Adjusted. There are 5 mainsails at the bottom, each moving ~2.5 orange tanks of fuel, so much, much more than you've got going on.

Thanks for confirming that Arcturus is incompatible to the extreme with this. I'll add my version of the thrust corrector post-haste with some code to detect if Arcturus is installed and to inform the user of the incompatibility so that other people don't have to suffer.

Alright sounds good, and yeah I'm using FAR to Real Life, Adjusted. I had a feeling something was a bit off. xD

Edited October 16, 2013 by CoriW

[Camacha]

I have a sneaking suspicion this is going to make my life a lot harder, but more realistic and thus more fun. I have found that mods inspired by realism challenge me to read up on the subjects, learning a lot along the way. And since things are based on reality, there is alreay a lot of reading to be done.

[colmo]

I presume the impact on liquid fuelled atmospheric craft like jets (and prop-powered craft a la Firespitter etc.) will be a big reduction in range?