[1.7-1.9] SMURFF: Simple Module adjUstments for Real-ish Fuel-mass Fractions 1.9.1 (02019 Nov 12)

[metalpoetza]

@Kerbas_ad_astra is it expected that liquid hydrogen engines from the CryoEngines packs have terrible performance (at least before unlocking cryotanks- haven't tried it with them yet) ? Sticking the small 1.25m cryo-engine on a 1.25m tank gives about 1/4 of the delta-V that you could get out of putting a terrier on the same tank.

I know LH2 is low-density so wants large tanks but its as if the engine ISP is way, way lower than it ought to be (the reason LH2 is a good rocket fuel is it's incredible ISP).

Or is this indicative of an issue with my install ? 

I've actually just unlocked the cryotanks in the high-performance-fuels node - and so far I've not yet used a cryoengine once, simply because at every stage they were - by far - the worst delta-V for mass option available. 

This makes me think there may be a bug (this is on 1.3.1).

If there is a bug, let me know what information I should share that could help fix it.

[Kerbas_ad_astra]

Simply swapping out the tank setups and engines is not going to produce good performance -- because LH2 is so lightweight (70 g/L vs. 1000 g/L for LF/OX), more tank volume is required to make up for it.  The last time I looked at this, the numbers did work out that, when I added more fuel tanks to get the delta-V numbers to match, the LH2 rocket was lighter than the conventional LV-909.  (It did, however, cost more funds, which is why I've not been a heavy user of LH2 rockets in my career.  The most likely use case I've considered is a cryogenic upper stage for an interplanetary probe to save much more mass on the LFO launcher.)

[metalpoetza]

2 hours ago, Kerbas_ad_astra said:

Simply swapping out the tank setups and engines is not going to produce good performance -- because LH2 is so lightweight (70 g/L vs. 1000 g/L for LF/OX), more tank volume is required to make up for it.  The last time I looked at this, the numbers did work out that, when I added more fuel tanks to get the delta-V numbers to match, the LH2 rocket was lighter than the conventional LV-909.  (It did, however, cost more funds, which is why I've not been a heavy user of LH2 rockets in my career.  The most likely use case I've considered is a cryogenic upper stage for an interplanetary probe to save much more mass on the LFO launcher.)

It does seem to be more viable once cryotanks are unlocked - if you use the big balloon tanks. Though this does significantly lower the applicability. I would suggest looking at it in terms of where LH2 is used in the real world. I think right now SMURFF is a bit more limited than reality. The space shuttle used LH2 for it's external booster for example. It's not generally a good fuel for a small satelite - because it's so bulky. It does make a good upper stage fuel - though right now that only becomes possible in-game once you have balloon tanks - I think it's a bit too punishing there, either that or the balloon tanks need to unlock earlier (or the engines later). The other major thing it is useful for is as an engine for injection burns. You launch something into orbit, the stage that does your burn to where-ever you're going uses LH2 for a nice lightweight fuel with lots of delta-V, then you discard that stage. Boil-off isn't a big problem then because you aren't taking it with you. But at least now I know that what I'm seeing is actually intended. If I'm genuinely unhappy with it - make a custom hack for myself, it's the way you want it to play.

[Kerbas_ad_astra]

I did use some fairly conservative numbers when estimating LH2 tank fractions, so I'll go over that math again and see what falls out.  Thanks for the feedback.

Edit: Also, it looks like CryoTanks' tank mass fractions got revised, so I'll definitely have to do some re-figuring.

Edited January 26, 2018 by Kerbas_ad_astra

[Dermeister]

Does SMURFF conflict with real fuels? Id i'm running a solar system that is 1/1 real solar system size and I have Real fuels but not Realism overhaul, Does SMURFF help me? is it recommended? What do people run these days if they want RSS size systems but do not want to install RO? I do like real fuels how ever!

[Kerbas_ad_astra]

SMURFF operates on stock resources only, so it shouldn't interact with Real Fuels at all.  (Nor does it need to, to my knowledge -- I understand that real fuels' tanks are already defined with realistic mass fractions.)  The only effect left over is making capsules and heat shields lighter (which may still be desirable, since Real Fuels doesn't do that.)

[Dermeister]

6 minutes ago, Kerbas_ad_astra said:

SMURFF operates on stock resources only, so it shouldn't interact with Real Fuels at all.  (Nor does it need to, to my knowledge -- I understand that real fuels' tanks are already defined with realistic mass fractions.)  The only effect left over is making capsules and heat shields lighter (which may still be desirable, since Real Fuels doesn't do that.)

ok thanks

[Kerbas_ad_astra]

On 1/26/2018 at 1:04 AM, metalpoetza said:

It does seem to be more viable once cryotanks are unlocked - if you use the big balloon tanks. Though this does significantly lower the applicability. I would suggest looking at it in terms of where LH2 is used in the real world. I think right now SMURFF is a bit more limited than reality. The space shuttle used LH2 for it's external booster for example. It's not generally a good fuel for a small satelite - because it's so bulky. It does make a good upper stage fuel - though right now that only becomes possible in-game once you have balloon tanks - I think it's a bit too punishing there, either that or the balloon tanks need to unlock earlier (or the engines later). The other major thing it is useful for is as an engine for injection burns. You launch something into orbit, the stage that does your burn to where-ever you're going uses LH2 for a nice lightweight fuel with lots of delta-V, then you discard that stage. Boil-off isn't a big problem then because you aren't taking it with you. But at least now I know that what I'm seeing is actually intended. If I'm genuinely unhappy with it - make a custom hack for myself, it's the way you want it to play.

 

On 1/26/2018 at 8:37 AM, Kerbas_ad_astra said:

I did use some fairly conservative numbers when estimating LH2 tank fractions, so I'll go over that math again and see what falls out.  Thanks for the feedback.

Edit: Also, it looks like CryoTanks' tank mass fractions got revised, so I'll definitely have to do some re-figuring.

Following up on this: I still need to run some testing to be certain I've got the 'feel' right, but from my research and calculations, I'm closing in on some new adjustment factors that will very slightly buff LFO tanks (taking them from just below 97% fuel to just above) and will substantially buff LH2O tanks (89% -> 93% fuel, comparable to e.g. Centaur).  The "extra" Ven's Stock Revamp patch will further adjust the CryoX tanks to be even lighter.  They will be baselined to the Space Shuttle Super Lightweight External Tank, and have 96.5% fuel mass fraction with LH2/Ox.

I will most likely take a step back from realism for the pure LH2 tanks.  Real ZBO storage systems are very heavy, more so than the fuel they contain (check out page 2 of this document for a diagram of all the parts), which is fine for propellant depots but not suitable for traveling spacecraft.  (And it would be a shame not to be able to use Nertea's sweet tanks for spacecraft!)

LH2 tanks will still be made a little heavier than they come stock in CryoTanks (but not terribly so, and Ven's balloon tanks will actually be made a little lighter), and the power requirement to nullify boil-off will also be increased, but not nearly as much as would be necessary for a true zero-boil-off system.  (To get the mass numbers to line up, depending on whether I bookkept the added mass in the tanks or in the power plants, Nertea's 10 meter storage tank would require four or thirty-seven of the largest 3.75m Near Future Electrical reactors to prevent boiloff...that's not happening.)

[metalpoetza]

3 hours ago, Kerbas_ad_astra said:

 

Following up on this: I still need to run some testing to be certain I've got the 'feel' right, but from my research and calculations, I'm closing in on some new adjustment factors that will very slightly buff LFO tanks (taking them from just below 97% fuel to just above) and will substantially buff LH2O tanks (89% -> 93% fuel, comparable to e.g. Centaur).  The "extra" Ven's Stock Revamp patch will further adjust the CryoX tanks to be even lighter.  They will be baselined to the Space Shuttle Super Lightweight External Tank, and have 96.5% fuel mass fraction with LH2/Ox.

I will most likely take a step back from realism for the pure LH2 tanks.  Real ZBO storage systems are very heavy, more so than the fuel they contain (check out page 2 of this document for a diagram of all the parts), which is fine for propellant depots but not suitable for traveling spacecraft.  (And it would be a shame not to be able to use Nertea's sweet tanks for spacecraft!)

LH2 tanks will still be made a little heavier than they come stock in CryoTanks (but not terribly so, and Ven's balloon tanks will actually be made a little lighter), and the power requirement to nullify boil-off will also be increased, but not nearly as much as would be necessary for a true zero-boil-off system.  (To get the mass numbers to line up, depending on whether I bookkept the added mass in the tanks or in the power plants, Nertea's 10 meter storage tank would require four or thirty-seven of the largest 3.75m Near Future Electrical reactors to prevent boiloff...that's not happening.)

That all sounds excellent. I look forward to playing with it. I agree that power consumption for avoiding boil-off should be steep. It makes a nice ballance then for the other changes - you still won't want to send LH2 on a deep-space mission due to all the power generation you would need (and full boil-off prevention requires enough power that no real space ship has even tried it yet - so it's definitely still gamey). 

Thanks dude.

[ragusila]

hey, awesome mod! Been playing with RO(and real fuels) for a few years, but I want to try the MKS and OPT spaceplane mods, and want to see the interior of ships at correct scale...so trying out the SMURFF in KSP 1.3.1 with RSS

The stock tanks seem to be changed well, to around 3.125% of their wet mass, but other tanks dont seem to be affected as much. Specifically, the SSTU configurable tanks are at around 12% of their wet mass, the LCA Energia tanks get changed from 12% to only 8%. The OPT spaceplane tanks seem to  be correctly changed to around 4-5% of their wet weight.

Trying to understand how the mod works...does it change the mass of dry tank based on it's fuel load, or based on its original weight? Or is it a combination of both? Can it affect configurable parts (SSTU, Procedural Parts) or are those out of the question?

Thanks! 

[Kerbas_ad_astra]

3 hours ago, ragusila said:

hey, awesome mod! Been playing with RO(and real fuels) for a few years, but I want to try the MKS and OPT spaceplane mods, and want to see the interior of ships at correct scale...so trying out the SMURFF in KSP 1.3.1 with RSS

The stock tanks seem to be changed well, to around 3.125% of their wet mass, but other tanks dont seem to be affected as much. Specifically, the SSTU configurable tanks are at around 12% of their wet mass, the LCA Energia tanks get changed from 12% to only 8%. The OPT spaceplane tanks seem to  be correctly changed to around 4-5% of their wet weight.

Trying to understand how the mod works...does it change the mass of dry tank based on it's fuel load, or based on its original weight? Or is it a combination of both? Can it affect configurable parts (SSTU, Procedural Parts) or are those out of the question?

Thanks! 

SMURFF handles parts in several ways, but the key function is that it assesses their resource content and deducts mass accordingly.  It affects a couple of procedural parts mods where the 'mass per volume' is an easily exposed variable, and as long as I bother to keep up with its changes.  Since I use Cryogenic Engines and Kerbal Atomics, I've adjusted my patches as Nertea has adjusted CryoTanks's balance (and another adjustment is coming with the next revision), but while I've made patches for Interstellar Fuel Switch and Procedural Parts, I don't use those mods myself so I don't really know if they still work.  (Based on a quick peek, it looks like they should, but maybe I should demote them to the 'extras' folder.)  I've glanced briefly at SSTU, but it's much more complicated than any other procedural-parts mod I've seen save Modular Fuel Tanks or RealFuels, and since I don't use it, I don't feel particularly inclined to try to spend time working out how to patch it.  I might take a pull request if someone figures it out (and the cure isn't worse than the disease).

On 1/30/2018 at 12:36 AM, metalpoetza said:

That all sounds excellent. I look forward to playing with it. I agree that power consumption for avoiding boil-off should be steep. It makes a nice ballance then for the other changes - you still won't want to send LH2 on a deep-space mission due to all the power generation you would need (and full boil-off prevention requires enough power that no real space ship has even tried it yet - so it's definitely still gamey). 

Thanks dude.

I just did a 'test' where I assembled a capsule-plus-tank-plus-engine using an LV-909, then made a stack with the same delta-V using the Chelyabinsk engine and hydrolox, and using cryogenic fuels saved over 2700 kg (from a 10-ton 'baseline' craft) and added almost 2,000 funds to the price tag (from 6000).  Previously, the mass difference was much smaller (saving less than 600 kg), so this new iteration feels better.  (If you've got funds to burn, you can use CryoX tank parts and get even greater mass savings, but they're pricey.)  It feels good, so I'm going for the next tests: surviving high-speed reentry and then a Moon landing (and return!).

Edited February 1, 2018 by Kerbas_ad_astra

[ragusila]

17 hours ago, Kerbas_ad_astra said:

SMURFF handles parts in several ways, but the key function is that it assesses their resource content and deducts mass accordingly.  It affects a couple of procedural parts mods where the 'mass per volume' is an easily exposed variable, and as long as I bother to keep up with its changes.  Since I use Cryogenic Engines and Kerbal Atomics, I've adjusted my patches as Nertea has adjusted CryoTanks's balance (and another adjustment is coming with the next revision), but while I've made patches for Interstellar Fuel Switch and Procedural Parts, I don't use those mods myself so I don't really know if they still work.  (Based on a quick peek, it looks like they should, but maybe I should demote them to the 'extras' folder.)  I've glanced briefly at SSTU, but it's much more complicated than any other procedural-parts mod I've seen save Modular Fuel Tanks or RealFuels, and since I don't use it, I don't feel particularly inclined to try to spend time working out how to patch it.  I might take a pull request if someone figures it out (and the cure isn't worse than the disease).

 

Thanks! will install Nertea mods and see if they are enough. BTW, looked more into SSTU, there are only 4-5 tanks (each can be modified in many ways) so changing mass to a 4% ratio is not hard at all. Will just write a small script for it. 
Curious, what tanks and engines do you usually use with SMURFF? The stock ones?
 

[Kerbas_ad_astra]

6 hours ago, ragusila said:

Thanks! will install Nertea mods and see if they are enough. BTW, looked more into SSTU, there are only 4-5 tanks (each can be modified in many ways) so changing mass to a 4% ratio is not hard at all. Will just write a small script for it. 
Curious, what tanks and engines do you usually use with SMURFF? The stock ones?
 

I mostly use stock parts, but I also like to use RLA Stockalike and Modular Rocket Systems for their wide assortment of small tanks and engines (especially the "Sparkler" from MRS, that's basically my workhorse engine for Earth escape probes), SpaceY and SpaceY Expanded to fill in the big end (5, 7.5, 10 m), and in between, I use HGR and MOLE to make the jump from 1.25 to 2.5 meter parts a little easier.  I've got a list of other mods I like to use in the OP.

[slaintemaith]

An add-on I'd like you to consider making 'work' with SMURFF is Pak's Cormorant Aeronology Shuttle.

It adds a great-looking STS type craft that works seamlessly with Gravity Turn (once you get the right numbers) and Kermantech's amazing IVA.

I know out-of-the-box when trying to make SMURFF work with RSS the SRBs seem overpowered and the ET doesn't have enough fuel.  I know there's a RO config for it here, but sadly I'm too stupid to convert the numbers to make it go.

Thanks for your consideration.

[Kerbas_ad_astra]

On 2/6/2018 at 11:53 AM, slaintemaith said:

An add-on I'd like you to consider making 'work' with SMURFF is Pak's Cormorant Aeronology Shuttle.

It adds a great-looking STS type craft that works seamlessly with Gravity Turn (once you get the right numbers) and Kermantech's amazing IVA.

I know out-of-the-box when trying to make SMURFF work with RSS the SRBs seem overpowered and the ET doesn't have enough fuel.  I know there's a RO config for it here, but sadly I'm too stupid to convert the numbers to make it go.

Thanks for your consideration.

Looking at the parts, I'm not surprised that they get treated a little strangely, since they are not balanced like stock parts.  (The tanks and SRBs are lighter than average.)  I don't use CA, so I'm not planning on going to the trouble of writing a patch for them (sorry).

For what it's worth, the math to make a patch for SMURFF would probably be easier than for RO, since there's no changing resources and (since everything uses Firespitter's fuel switch module rather than bare resources) no need to worry about e.g. handling Cryo Tanks or other mod interactions.

[slaintemaith]

Well it was worth a shot.  =)

[Kerbas_ad_astra]

SMURFF version 1.7.0 "Zero Level" is released!

• Adjusted tank math to remove divide-by-zero error. Feel free to set tanklever = 0 now!
• Rebalance of tank adjustment factors to adapt to changes in Near Future Propulsion and CryoTanks (and some in response to user feedback). LFO and hydrolox tanks got a bit of a buff, most everything else stays put. Because the corresponding versions of NFP and CryoTanks were released for KSP 1.3.1, this version and later versions are not compatible with KSP 1.2.2 or 1.3.0.
• The "Extra" patch for Ven's Stock Revamp is more detailed, and now has different behavior for when CryoTanks is or is not installed. Their performance is baselined to the Super Lightweight (Space Shuttle External) Tank.

For those interested, here's the mission I flew to test it as well as its interactions with MandatoryRCS and Throttle Limit Extended (spoiler alert: I like them!):

Album a/YR3Us will appear when post is submitted

Edited February 10, 2018 by Kerbas_ad_astra
Trying to fix album

[falken]

I'm trying to get a realistic tank weight for a 3.2 scale Kerbin. What would you guys say would be the most appropriate? I'm also using a MM script to lower engine isps as well. Had them at 0.67 of normal, now trying 0.47.

[Masterredlime]

I need help modifying the dry mass of the cryogenic tanks such as the Mondo-60 Hydrogen Tank because the dry mass is way heavier than the hydrogen propellant mass inside the tank, I tried writing a module manager config in the game data folder first and also changing the lh2zbofactor = 0.6049 in the SMURFF config notepad to lh2zbofactor = 0.301072. However, this did not change the dry mass of the CryoTank hydrogen tanks' dry mass and they still remain heavier than their hydrogen propellant mass. The module manager config file that I wrote was called CryogenicTank.cfg and inside the config file I wrote:

// This is to config the dry mass of the cryogenic tanks to be lighter

@PART[hydrogen-10-1]:Final
{
  mass = 0.25
}

@PART[hydrogen-25-1]:Final  
{
  mass = 0.25
}

@PART[hydrogen-25-2]:Final  
{
  mass = 0.25
}

@PART[hydrogen-25-3]:Final  
{
  mass = 0.25
}

@PART[hydrogen-125-1]:Final  
{
  mass = 0.25
}

@PART[hydrogen-125-2]:Final  
{
  mass = 0.25
}

@PART[hydrogen-375-1]:Final  
{
  mass = 0.25
}

@PART[hydrogen-375-2]:Final  
{
  mass = 0.25
}

@PART[hydrogen-375-3]:Final  
{
  mass = 0.25
}

@PART[hydrogen-radial-25-1]:Final  
{
  mass = 0.25
}

@PART[hydrogen-radial-125-1]:Final  
{
  mass = 0.25
}

@PART[hydrogen-radial-375-1]:Final  
{
  mass = 0.25
}

There were no module manager errors while booting up KSP which meant the lines were correct, however the mass of the tanks are still unchanged and I'm unable to use hydrogen tanks as a viable tank to prevent boiloff and interplanetary travel. If anyone sees this I've been spending the whole day trying to change the mass of the tanks, and I'm now desperate to fix this issue. Any help will be much appreciated. KSP version is 1.2.2

Edited February 14, 2018 by Masterredlime

[Kerbas_ad_astra]

The latest version of SMURFF reduces the mass fraction of hydrogen tanks more-or-less across the board, so if you update to KSP 1.3.1 that should improve matters for you.

As for your self-made patch, you need to use "@mass = whatever" to modify a value.

I don't use KSP 1.2.2 any more, so I'm not able to help you much beyond that.

[metalpoetza]

13 hours ago, Kerbas_ad_astra said:

The latest version of SMURFF reduces the mass fraction of hydrogen tanks more-or-less across the board, so if you update to KSP 1.3.1 that should improve matters for you.

As for your self-made patch, you need to use "@mass = whatever" to modify a value.

I don't use KSP 1.2.2 any more, so I'm not able to help you much beyond that.

I can confirm this. I just did a test. The H250-64 hydrogen tank weighs 700kg empty, over 2 tonnes full.

[Flavio hc16]

for me the mods doesn't work for the fuel tanks (1.31) it shows the updated specs in the vab/sph list, but not when you place and play with the object, I have tried to change also the value from the config but it didn't work. For the engines and the capsule it works fine ( yes, i have checked that i have changed every value to the same number in the config)

https://imgur.com/eX7jpk0

in the image you can see that it says something in the description and something else in-game

[Kerbas_ad_astra]

6 hours ago, Flavio hc16 said:

for me the mods doesn't work for the fuel tanks (1.31) it shows the updated specs in the vab/sph list, but not when you place and play with the object, I have tried to change also the value from the config but it didn't work. For the engines and the capsule it works fine ( yes, i have checked that i have changed every value to the same number in the config)

https://imgur.com/eX7jpk0

in the image you can see that it says something in the description and something else in-game

What other mods (if any) are you using?

Edited March 11, 2018 by Kerbas_ad_astra

[Flavio hc16]

17 hours ago, Kerbas_ad_astra said:

What other mods (if any) are you using?

imho the ones that are messing something are

interstellar fuel switch/ B9partswitch

and else i have

 kis

kas

umbrellaspace industries/spacey/spacey expanded/space station redux/planetary base/thunder aerospace

CTTP

firespitter/

wildblueindustries

mark4 system, mk3 expanded

scatterer /windowshine/eve/sve

recoupler/ vessel easy switch/hangar extender/flexible docking/ fuel pump/rcs aid

 

[Kerbas_ad_astra]

The "full" version of Interstellar Fuel Switch comes with a patch (InterstellarFuelSwitch/PatchManager/ActiveMMPatches/IntegrationLiquidFuelOxidizer.cfg) that adds a fuel switcher module to all parts.  SMURFF has code which should handle that, though.

Unfortunately, I need to ask you to sort through your mods and figure out exactly which ones are causing the issue.  I use most of those mods myself, and don't have this issue.