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[WIP] RealChute Material Extensions


AlmightyR
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Hello everyone.

I've been a big fan of the RealChute mod for a long time, and I consider it one of the absolutely essential mods to have on any of my KSP installs.

One thing has always bothered me slightly, however, and that is that, specially when paired with DeadlyReentry, even the Kevlar drogue parachutes with very light loading will instantly fail above a certain altitude (above 10-15km~) on reentry, but the idea, and even technology, of "parachutes" rated for reentry does exist, as do flexible(~) materials stronger and/or more heat-resistant than Kevlar.

For example:
Silica can be processed and woven into fabrics rated for 1800°F (980°C), for example.

Carbon fiber being woven into fabrics is already a thing too. And apparently carbon tensile strength actually peaks at 1500-2000 °C with 5,650 MPa/820,000 psi, and carbon fibers heated in the range of 2500-3000 °C exhibit a modulus of elasticity of 531 GPa, or 77,000,000 psi (!!!). (for comparison, Kevlar fibers only have 3,620 MPa, 525,380 psi)

Oh yea, and last but not least, chutes could be made of multiple layers and/of composite materials.

 

So yea, in my humble opinion, Kevlar might still come with an anchor tattoo, but it should very much NOT be the strongest material available! Our dreams of conquering and settling the whole of the Kerbol system and beyond should not be limited by a lackluster set of parachute materials!

 

HOWEVER!

I am not a material engineer. I'm not anywhere close to any scientific fields. In fact I even suck at math.

So! Community! I need your help(s) to research and understand this stuff so I can implement these

RealChute Material Extensions!

(pah-dum-tss)

 

 

Ways you can help me help you get some of that juicy juicy material booty:

  • Research:
    • Find viable parachute materials!
    • As close as possible to the fabric of that material that can be found or somewhat reliably assumed/extrapolated/calculated with some accuracy, find:
      • areaDensity
      • dragCoefficient
      • areaCost
      • maxTemp
      • specificHeat
      • emissivity
    • Speaking of that, I have no idea what the 'specificHeat' and 'emissivity' parameters are in the existing materials. Explanations welcome! (And again, sorry, outside of the everyday basics, I'm not a thermodynamics-savvy guy)
    • What is thermodynamics? And will it scream if I poke it with a stick?
    • What is material science (specially this tensile strength stuff that seems really important for parachutes)? And will it end the kuniverse through a big rip?
  • Testing:
    • For whatever materials that are currently included in the mod as fully implemented or WIP, play around and if you find issues of any kind, tell me!
      • For suggestions of balance or realism, it's important that you justify the reasons for the suggestion, either with good arguments or with verifiable data. Preferably verifiable data.
         

Materials implemented thus far:

  • Fully implemented:
    • None.
       
  • WIP:
    • Carbon Fabric.
      • areaDensity: Unknown - Currently approximated to 0.000072 by guesswork (same as RC's Kevlar).
      • dragCoefficient: Unknown - Currently approximated to 1.25 by guesswork (same as RC's Kevlar).
      • areaCost: Unknown - Currently approximated to 0.16 by guesswork (2 times the cost of RC's Kevlar).
      • maxTemp: Semi-unknown - Currently approximated to 2273.15 K (2,000 C) based on temperatures from the wiki page on Carbon Fibers.
      • specificHeat: 795.492 - Based on specifications of commercial products.
      • emissivity: Unknown - Currently approximated to 0.5 by guesswork (rounded number close to the same as RC's Kevlar).
         
    • Silica Fabric.
      • areaDensity: Unknown - Currently approximated to 0.000072 by guesswork (same as RC's Kevlar).
      • dragCoefficient: Unknown - Currently approximated to 1.25 by guesswork (same as RC's Kevlar).
      • areaCost: Unknown - Currently approximated to 0.12 by guesswork (1.5 times the cost of RC's Kevlar).
      • maxTemp: Semi-unknown - Currently approximated to 1273.15 K (1,000 C) based on specifications of commercial products; specially heat-resistant curtains/blankets for welding.
      • specificHeat: Semi-unknown - Currently approximated to 1420 based on guesswork (same as RC's Kevlar)
      • emissivity: Unknown - Currently approximated to 0.5 by guesswork (rounded number close to the same as RC's Kevlar)

Download:

SpaceDock

 

NOTICE:

I've changed the mod folder name (and the mod name in general) as of today (Version 0.1.2).

This was done to remove the 'AlmightyR_' prefix from the name, since apparently that is not supported by ModuleManager and would need the underscore to be replaced by a '?' for user/sub-mod patches.

As well as to improve grouping with the parent mod in searches and lists and stuff like that.

If you have installed versions previous to 0.1.2, DELETE THE OLD MOD FOLDER ("AlmightyR_MaterialExtensionsForRealChute") before installing this version.

 

License:

CC BY-NC-SA 4.0

Summary:

You are free to:

  • Share — copy and redistribute the material in any medium or format
  • Adapt — remix, transform, and build upon the material

Under the following terms:

  • Attribution — You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
  • NonCommercial — You may not use the material for commercial purposes.
  • ShareAlike — If you remix, transform, or build upon the material, you must distribute your contributions under the same license as the original.
  • No additional restrictions — You may not apply legal terms or technological measures that legally restrict others from doing anything the license permits.

 

Edited by AlmightyR
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Nice... Kinda surprised you havent gotten moar response, @AlmightyR Hopefully with an actual download available, you'll get moar interest. ;)

Also, just an FYI, per forum rules, you should clearly state your license selection in the OP, as well as add a text file in the .zip stating it as well ;)

Especially if you end up adding any different textures, or actual custom Unity materials in the future.

Edited by Stone Blue
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1 hour ago, Stone Blue said:

Nice... Kinda surprised you havent gotten moar response, @AlmightyR Hopefully with an actual download available, you'll get moar interest. ;)

Also, just an FYI, per forum rules, you should clearly state your license selection in the OP, as well as add a text file in the .zip stating it as well ;)

Especially if you end up adding any different textures, or actual custom Unity materials in the future.

Ok! Missed those little details; thought just having a license in the SpaceDock page was enough. Thanks for the info! I'll include the license here and on the mod folder in just a moment! EDIT: Done!

 

Also, thanks for the support!

Edited by AlmightyR
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1 hour ago, AlmightyR said:

Ok! Missed those little details; thought just having a license in the SpaceDock page was enough. Thanks for the info! I'll include the license here and on the mod folder in just a moment! EDIT: Done!

 

Also, thanks for the support!

Hey @AlmightyR,
the license is "hardcoded" in the CKAN metadata. When you change it, please notify the CKAN team so we can adjust it, or preferably, do a PR over at the NetKAN repo. Thanks!

Edited by DasSkelett
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1 hour ago, DasSkelett said:

Hey @AlmightyR,
the license is "hardcoded" in the CKAN metadata. When you change it, please notify the CKAN team so we can adjust it, or preferably, do a PR over at the NetKAN repo. Thanks!

Got it! Thanks for helping me get to know the little details of modding in KSP guys! :)

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I suggest to

  1. get rid off the underscore in the folder name AlmightyR_MaterialExtensionsForRealChute because that is commonly not done like that (to avoid user patches being borked because they forgot to replace the _ with a ? in their HAS)
  2. even totally change the folder name for better sorting order and having it in place, to be easily found in GameData and not overseen, like RealChuteAlmightyRMaterialExtensions
  3. just simply add :NEEDS[RealChute] behind the MATERIAL blocks
  4. I even suggest to add a :FOR[RealChuteAlmightyRMaterialExtensions] (or however you call it then) to have a defined name to check for in later NEEDS for other patches

(4. is wrong - because it's an insert node)

btw, the mod InlineBallutes already got one MATERIAL defined in
https://github.com/linuxgurugamer/InlineBallutes/blob/master/GameData/KermangeddonIndustries/InlineBallutes/Patches/RealChute.cfg
(it does not differ to the MATERIAL block in the realChute_FAR.cfg at all)

MATERIAL:NEEDS[RealChute,!FerramAerospaceResearch]
{
	name = ZylonBallute
	description = Much stronger and resistant to heat than Kevlar however prone to sunlight radiation thus is only one time use.
	areaDensity = 0.0002278
	dragCoefficient = 0.20
	areaCost = 0.24
	maxTemp = 1100
	specificHeat = 25600
	emissivity = 600
}

I'm not sure if this is just some fantasy or real values. Expecially the really high specificHeat value.

I already considered in adding a patch to overwrite that material. Which one would you suggest?

 

Edited by Gordon Dry
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23 hours ago, Gordon Dry said:

I suggest to

  1. get rid off the underscore in the folder name AlmightyR_MaterialExtensionsForRealChute because that is commonly not done like that (to avoid user patches being borked because they forgot to replace the _ with a ? in their HAS)
  2. even totally change the folder name for better sorting order and having it in place, to be easily found in GameData and not overseen, like RealChuteAlmightyRMaterialExtensions
  3. just simply add :NEEDS[RealChute] behind the MATERIAL blocks

Agreed and made the changes. In order to keep the mod name consistent to it's folder, also changed the name of the mod in general to RealChute Material Extensions. Thanks for the feedback!

 

As for ZylonBallute and it's specificHeat value, I imagine it should be real, but I can't know if it is in fact real. I'm not the author and don't know his process or reasons there, and have no idea what "Zylon" is, as a material.

As such, I can't have any meaningful recommendations. It depends entirely on what you want in your KSP experience.

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  • 1 month later...

I have looked into this before, though I've not done extensive work on the math for all the materials yet, nor actually coded any of them for use in KSP.  Back over in the original Realchute thread though, I posted this a while back (april 2018):
 

Quote

If desired, I could work out all the math for all the materials (I only directly looked at Silk and Nylon so far) based on the material information from the US Naval Weapons Center "Parachute Recovery Systems Design Manual" - it has full specs and requirements for not only Nylon, Silk, and Kevlar, but also for Cotton Canvas, Rayon, Dacron, Nomex, E Glass, and Graphite (which is particularly interesting because of its complete lack of stretching under tension and a useful temperature up to 2,760 C - hellaciously expensive and slightly heavier than kevlar though).  The same source has a bunch of information on masses for the other components in the system, effectiveness of various shapes, etc etc, but the only thing that I can see directly being applicable is the canopy materials info, since we don't have multiple canopy shapes implemented, and case mass is already a sort of fudge-factor for KSP anyway...

You might start by reading over the referenced manual, which is available at this address in pdf form.  Would definitely like to see (at least some of) these additional materials included as Realchute materials - but since the last word I heard was that RealChute as it currently exists was no longer in development, and was instead being rewritten as RealChute 2.0 from the ground up, I had not gone any further with it.

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