[1.12.*] Deadly Reentry v7.9.0 The Barbie Edition, Aug 5th, 2021

[Starwaster]

14 hours ago, Iso-Polaris said:

The ablative barely being consumed on a ~3000m/s reentry when DRE is installed, is it suppose to happen ?

I have a sigma dimension rescaled (3.7x) system, should there's be special config for this kind of system size ?

 

Unfortunately, what's probably needed here is a config that dynamically adjusts to rescaled systems, instead of a one size fits all solution.

It's something that I've wanted to do for awhile but have never gotten around to it.  (basically check what the home planet has been rescaled to and do a little math and figure out how much to adjust the heat shield based on the difference between stock Kerbin and the rescaled Kerbin)

So, what's happening is this: An assumption is being made that your system is being rescaled bigger than it really is. ALSO, a realism factor is being applied to the ablation rate because in real life, a heat shield ablates a mere fraction of its total amount than would happen in stock KSP. In stock KSP, I'm still trying to capture the basic essence of your ablator being sucked nearly dry. But IRL, an Apollo heat shield only ablated (IIRC) only 10%-ish of its total amount.

(Because, overengineering)

The greatest heat loading ever experienced by a heat shield was by the Galileo Jupiter Atmospheric Probe which ablated something like 50% of its heatshield. (might have been more/less, going by memory)

The easiest solution for you here is to use the Deadly Reentry menu to crank up reentry heating. (there's one in the stock KSP menus but it's clamped to 200%. The DR one overrides the KSP one and goes a lot higher)

That solution, while being easiest to execute will affect everything even supersonic aircraft, so you could instead use an MM config to make the ablation rate faster. The following will double all heatshield consumption rates: (adjust lossConst to suit your desires)

@PART[]:HAS[@MODULE[ModuleHeatShield]]:LAST
{
	@MODULE[ModuleHeatShield]
	{
		@lossConst *= 2
	}
}

 

[Iso-Polaris]

I've since find the DeadlyReentry_AlternateStarSystems config is causing the incorrect ablation consumption.

@PART[*]:HAS[@MODULE[ModuleHeatShield],~RSSROConfig[True]]:FOR[DeadlyReentry]:NEEDS[Sigma,!RealismOverhaul]
{
	@skinMaxTemp *= 1.091
	@MODULE[ModuleHeatShield]
	{
		@lossExp = -40000
		@lossConst = 150000
		@pyrolysisLossFactor = 4000
	}
}

It seems that this one is configurated for a x10+ rescale because the numbers are exactly the same as those for RO, how do I adjust those factor to fit the reentry speed of a 3.7x rescale, is there an explaination for "lossExp" and "pyrolysisLossFactor" ?

[Starwaster]

12 hours ago, Iso-Polaris said:

I've since find the DeadlyReentry_AlternateStarSystems config is causing the incorrect ablation consumption.

@PART[*]:HAS[@MODULE[ModuleHeatShield],~RSSROConfig[True]]:FOR[DeadlyReentry]:NEEDS[Sigma,!RealismOverhaul]
{
	@skinMaxTemp *= 1.091
	@MODULE[ModuleHeatShield]
	{
		@lossExp = -40000
		@lossConst = 150000
		@pyrolysisLossFactor = 4000
	}
}

It seems that this one is configurated for a x10+ rescale because the numbers are exactly the same as those for RO, how do I adjust those factor to fit the reentry speed of a 3.7x rescale, is there an explaination for "lossExp" and "pyrolysisLossFactor" ?

Yes, it's calibrated for x10

You're probably just better off with that patch I provided. Or at least that would be easiest. The formula that uses those fields is a little convoluted to use.

I used a spreadsheet as an aid. I opened it up to viewing and copying:
https://docs.google.com/spreadsheets/d/1_1LCCm7O5Yp8sdgU-GxlKre-iSjHs_B0AiO5bcy0gwA/edit?usp=sharing

(stay in the M column for starters)

Basically though, the formula is loss = lossConst * EXP(lossExp / skinTemperature) 

That's how much shield is consumed per second at skinTemperature. (in the VAB, infoTemp is used instead which is 2400 by default. It should be set to a typical reentry temperature for your system's scale. Assume temp Kelvin = velocity in meters per second, so set infoTemp to that value for what gets displayed in the VAB. It won't affect flight scene at all)

So, the game uses that loss to determine how much flux to remove from the shield

flux = loss * density * pyrolysisLossFactor * specific heat of ablator

This is all from the stock ModuleAblator which is the parent of ModuleHeatShield. maxAmount of the ablator resource factors in there but I forget how. Understand that I'm largely going by memory. The spreadsheet is accurate though in how the formula is used. Ignore that loss is used as a label 3x, that was just to get loss to something I could use to calculate flux.

[Iso-Polaris]

Sorry Im quite bad at reading configs

So what's the basic lossExp value for DRE with stock system? is it -6000 or -7500, I've seen both number come up in the config file

[Starwaster]

On 1/11/2024 at 5:45 PM, Iso-Polaris said:

Sorry Im quite bad at reading configs

So what's the basic lossExp value for DRE with stock system? is it -6000 or -7500, I've seen both number come up in the config file

lossExp -6000 shouldn't be in any Deadly Reentry config file. I used that a few times in the spreadsheet because I was testing different values there. But  not in the actual config files in the release.

[not-a-cylon]

This mod has been pretty essential in my game since the beginning. Last time I played was 5-6 years ago and I've found myself hooked again.

I've found the Near Future mods to be pretty great in terms of mixing into the stock, but I noticed that they don't seem to have good heat values with Deadly Reentry. As a quick and dirty fix, would doing this cause big problems other than some parts being overpowered?

@PART[*]:HAS[#author[Chris?Adderley*]]:FOR[DeadlyReentry]
{
	MODULE
	{
		name = ModuleAeroReentry
		leaveTemp = True
	}
}

This essentially un nerfs the temperatures for Near Future by filtering the author "Chris Adderley (Nertea)"

Or even better, does anyone have configs for Near Future to work with Deadly Reentry?

[Starwaster]

11 hours ago, not-a-cylon said:

This mod has been pretty essential in my game since the beginning. Last time I played was 5-6 years ago and I've found myself hooked again.

I've found the Near Future mods to be pretty great in terms of mixing into the stock, but I noticed that they don't seem to have good heat values with Deadly Reentry. As a quick and dirty fix, would doing this cause big problems other than some parts being overpowered?

@PART[*]:HAS[#author[Chris?Adderley*]]:FOR[DeadlyReentry]
{
	MODULE
	{
		name = ModuleAeroReentry
		leaveTemp = True
	}
}

This essentially un nerfs the temperatures for Near Future by filtering the author "Chris Adderley (Nertea)"

Or even better, does anyone have configs for Near Future to work with Deadly Reentry?

Basing the patch on author seems a bit too sweeping. If there are specific parts that are at issue then maybe you could base it on category. When people complain about this sort of thing, it's usually radiators, in which case you might target category thermal. 

You should definitely NOT schedule it in FOR[DeadlyReentry]. Either schedule it BEFORE in the contingency that I might at some point in the future add special Near Future handling or AFTER to specifically overwrite such special handling. Or you could even use the FINAL phase which tries to put it dead last.

Edit: If a list of specific parts is presented to me along with suggested temps, then I could include patches in the the mod. Although certain parts like the space station parts should probably be left as is. I don't see those as being particularly resistant to reentry.

Edited January 30 by Starwaster

[not-a-cylon]

13 hours ago, Starwaster said:

Basing the patch on author seems a bit too sweeping. If there are specific parts that are at issue then maybe you could base it on category. When people complain about this sort of thing, it's usually radiators, in which case you might target category thermal. 

You should definitely NOT schedule it in FOR[DeadlyReentry]. Either schedule it BEFORE in the contingency that I might at some point in the future add special Near Future handling or AFTER to specifically overwrite such special handling. Or you could even use the FINAL phase which tries to put it dead last.

Edit: If a list of specific parts is presented to me along with suggested temps, then I could include patches in the the mod. Although certain parts like the space station parts should probably be left as is. I don't see those as being particularly resistant to reentry.

Gotcha, I'll be doing :BEFORE then while I dig through parts and experiment a bit.

The one in particular that really prompted this post was the Shielded 5-Way RCS Block (name = rcsblock-aero-5way-1) from Near Future Spacecraft that was nerfed down to 1000 while the stock RCS blocks have 1500 despite having more exposed unshielded parts. Some other shielded parts like landing legs looked like they were being nerfed to below other stock parts. I'll get back to you for sure with specific stuff.

Thanks for keeping the mod maintained!

[Starwaster]

37 minutes ago, not-a-cylon said:

Gotcha, I'll be doing :BEFORE then while I dig through parts and experiment a bit.

The one in particular that really prompted this post was the Shielded 5-Way RCS Block (name = rcsblock-aero-5way-1) from Near Future Spacecraft that was nerfed down to 1000 while the stock RCS blocks have 1500 despite having more exposed unshielded parts. Some other shielded parts like landing legs looked like they were being nerfed to below other stock parts. I'll get back to you for sure with specific stuff.

Thanks for keeping the mod maintained!

I think I have that mod installed. I'll take a pass at those parts. 1000 is pretty low, not sure why it would be. (in theory it shouldn't go lower than 1523.15, but there's some extra math in there that could drive it lower)

maxSkinTemp is the most important one but if it's not defined then it equals maxTemp. If it's supposed to be an aerodynamic part then I might just bump up its skin max.

[dlrk]

I wound up adding that MM config for Nertea's parts. The issue was the command pods from NFS though

[not-a-cylon]

The radial decouplers with stock solid boosters explode before the boosters burn out in first stage low atmospheric use. I'm using FAR, so maybe I reach speeds not normal for stock, but I don't think this is likely as I shoot for ~1.6 TWR in the first stage. Is this intentional? I see  that DRE nerfs them down to 1000K, but is commented to 1600.

Here's what DRE does

@PART[radialDecoupler]
{
	@maxTemp = 1000 // 1600
}
@PART[radialDecoupler1-2]
{
	@maxTemp = 1000 // 1600
}
@PART[radialDecoupler2]
{
	@maxTemp = 1000 // 1600
}

and here's what I've done

 

@PART[radialDecoupler*]:AFTER[DeadlyReentry]

{
	@maxTemp = 1600
	name = ModuleAeroReentry
	leaveTemp = True
}

 

[Starwaster]

@not-a-cylon

I haven't seen a problem with decouplers specifically and they should survive an ascent to orbit. But you haven't given me enough information about your play environment. For instance whether you're playing with stock sized Kerbin or scaled up. In stock, convective heating from supersonic/hypersonic speeds is scaled up. That by itself isn't enough, but FAR changes how exposed surfaces are calculated and how parts are occluded so  the part is probably picking up more convective heating than it normally would. Other mods that can change how much of the part is exposed is Restock and Stock Revamp and I haven't tested with either of those mods. FAR I have tested with but mainly in scaled up systems. FAR + stock, not so much.

[not-a-cylon]

@Starwaster Stock Kerbin + Far, but also with Restock. That's wild! Digging around in the Restock module manager patches, it does look like Restock changes something with the radial decouplers, possibly how parts attach to it. Restock only seems to change effects for the SRBs. For now, my custom 1600K adjustment seems to be holding fine. 

[Starwaster]

21 hours ago, not-a-cylon said:

@Starwaster Stock Kerbin + Far, but also with Restock. That's wild! Digging around in the Restock module manager patches, it does look like Restock changes something with the radial decouplers, possibly how parts attach to it. Restock only seems to change effects for the SRBs. For now, my custom 1600K adjustment seems to be holding fine. 

What matters for Restock is whether or not they changed to a different model for the decouplers which would affect its exposure and possibly also how it interacts with the thermal shockwave. (shape matters)