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

[Dante80]

I don't think he meant that to be rude, though I don't think such a feature has a place in DRE. It sounds more of a MechJeb/Kerbal Engineer thing.

Yep, pretty much. DRE mostly deals with the actual physics of re-entry (as well as the parts needed to survive it). A KER entry in the surface tab (for example) would be ideal for such a feature, and also very handy for calculating your angles if you have the fuel for it..C:

On the other hand, just guessing the angle is not very difficult if you are paying attention to your retrograde marker.

Edited December 2, 2013 by Dante80

[sirklick]

IIRC, this was a problem with previous versions of DR and Nathan is working on a solution.

In a similar vein of disintegrating a lot while testing something, has anyone been able to get ballistic reentries to work with RSS and DR on hard-mode (heat multiplier = 25)?

I'm trying to test an ICBM type re-entry (flight profile: launch up to about 500km, separate payload and re-enter at a relatively steep angle to target the continent to the east of KSC). I've tested using a custom ProcFairing with increased heat-resistance and a built-in ablative shield, but no matter what I do the G-force destroys the craft at about 50km.

Just wondering what I can do differently, or is it even possible with DR?

Your velocity coming in from such an altitude is going to be quite high and your entry angle will likely be nearly perpendicular. RL ICBM's go to extremes to protect the payload from heat/G-forces (maximum flight altitude ~400km), measures I cant imagine possible to implement via DR aside from altering the the G/temp limits of the cargo.

[diomedea]

In a similar vein of disintegrating a lot while testing something, has anyone been able to get ballistic reentries to work with RSS and DR on hard-mode (heat multiplier = 25)?

I'm trying to test an ICBM type re-entry (flight profile: launch up to about 500km, separate payload and re-enter at a relatively steep angle to target the continent to the east of KSC). I've tested using a custom ProcFairing with increased heat-resistance and a built-in ablative shield, but no matter what I do the G-force destroys the craft at about 50km.

Just wondering what I can do differently, or is it even possible with DR?

While I don't use RSS, I have DRE set on hard mode and, till now, no problems. I recently made a direct reentry from a high transfer orbit with a Mk1-2 pod shielded, speed more than 2500 ms @35000 altitude, went really hot but all well in the end. Then I see about your ICBM profile, build a rocket to make the same, launch and all goes right: the payload gets hot @ 750°C (max speed while falling 1500 m/s) but survives and is destroyed at the impact point.

I suspect the issue may lie with the Reentry Vehicle (RV), as you know, in reality ICBM RVs are just the warheads and those are simple and robust enough. My RV was just a Sensor Array Nose Cone. But you're talking of something requiring fairings to withstand the reentry (real ICBM fairings are dropped outside the atmosphere) so your "payload" must be much more complex than a warhead, and complex vessels may hide weak points. It could be a single component failed due to the drag, and the whole structure of your RV collapsed as a result.

[BlackGlass Sand]

IIRC, this was a problem with previous versions of DR and Nathan is working on a solution.

Thanks for the reply. Yeah, Medieval Nerd mentioned just now in the other thread that it's probably a stock issue when you blow up while in flames...= therefore DR highlights this stock bug. Oh well.

[amo28]

While I don't use RSS, I have DRE set on hard mode and, till now, no problems. I recently made a direct reentry from a high transfer orbit with a Mk1-2 pod shielded, speed more than 2500 ms @35000 altitude, went really hot but all well in the end. Then I see about your ICBM profile, build a rocket to make the same, launch and all goes right: the payload gets hot @ 750°C (max speed while falling 1500 m/s) but survives and is destroyed at the impact point.

I suspect the issue may lie with the Reentry Vehicle (RV), as you know, in reality ICBM RVs are just the warheads and those are simple and robust enough. My RV was just a Sensor Array Nose Cone. But you're talking of something requiring fairings to withstand the reentry (real ICBM fairings are dropped outside the atmosphere) so your "payload" must be much more complex than a warhead, and complex vessels may hide weak points. It could be a single component failed due to the drag, and the whole structure of your RV collapsed as a result.

Yea. My ultimate goal isn't really a warhead -- I just want to drop payloads onto different continents. You're right that certain shielded components do fail due to G-load, but ultimately the entire vehicle does not reach impact before being destroyed, even the components with ablative shielding and high g-tolerance.

Thanks for testing it out though. The figures from RSS are a little more extreme than what you saw though -- speed at atmo re-entry is about 5500m/s, max temperature is 1400-1700°. The vehicle gets to 50-60km before heating up, but it's all over by the time it gets to 20km.

[FlowerChild]

I don't think he meant that to be rude, though I don't think such a feature has a place in DRE. It sounds more of a MechJeb/Kerbal Engineer thing.

Yup, it's entirely possible that it wasn't the intention, I just think it's worth keeping in mind the context in which mods are developed, and that phrasing things as a request rather than as a demand or expectation goes a long way in showing appreciation for the effort involved in providing the rest of us with free entertainment. When I see phrases like "you should" or what have you, directed at a modder, it tends to get my goat as a result

From experience, I know that dealing with an ungrateful and demanding public is a surefire way of killing a modder's spirit, when without any real profit motive, they are often just providing this stuff out of good will and enjoyment of making mods as a recreational activity. I also know that often times when I pop into this thread (and many KSP mod threads for that matter) to see what's been going on there's an awful lot of "I want" from the public relative to the gratitude expressed for what's already there.

[diomedea]

Yea. My ultimate goal isn't really a warhead -- I just want to drop payloads onto different continents. You're right that certain shielded components do fail due to G-load, but ultimately the entire vehicle does not reach impact before being destroyed, even the components with ablative shielding and high g-tolerance.

Thanks for testing it out though. The figures from RSS are a little more extreme than what you saw though -- speed at atmo re-entry is about 5500m/s, max temperature is 1400-1700°. The vehicle gets to 50-60km before heating up, but it's all over by the time it gets to 20km.

That being the case, your find is interesting. DRE works fine in my tests, even on hard mode. I don't use RSS, but think it is totally OK by itself. But the combination of both DRE and RSS is lethal. Now, that makes totally sense: spacefaring from Kerbin is much easier than from Earth. The re-entry speed of 5500m/s you measured is totally within the range of speeds for ICBMs IRL.

Anyway, I don't think IRL it would be possible to use a ICBM to deploy cargo. The warheads can arrive intact because optimized in size and profile so to cut through atmosphere at extreme speed, actually almost insensitive to drag (drag would increase CEP, Circular Error Probability). Your payload however isn't designed to sustain lithobraking at Mach 10 or more, so you want to decelerate before. The best way to decelerate at such speed is by aerobraking, but to do so properly your reentry profile must be shallow, while ICBM warheads go down deep. Problem is, with any suborbital profile you don't get a shallow reentry: to do so you need to get to orbital speed, then go retrograde more or less when over the antipode of the place you want to "hit".

[nothke]

@nothke: That looks about right for a bow shock in Mach ~1.4 flow; try to make the shock tend towards the Mach angle as it heads away from the craft, and make it a little tighter around the object.

As an idea of what you should be going for:

Bullet shadowgraph, Mach ~1.5

Apollo capsule CFD simulation, 14 degree AoA, Mach 4.9

Mercury capsule shadowgraph, Mach ~3

What you have is a good starting point, but it needs a little bit of tweaking; perhaps an animation that is set to vary with Mach number could be used for this?

I used a similar Schlieren shadowgraph (this one http://upload.wikimedia.org/wikipedia/commons/thumb/2/23/Blunt_body_reentry_shapes.png/709px-Blunt_body_reentry_shapes.png) and arc jet tests footage for the curvature. http://www.nasa.gov/centers/ames/images/content/255960main_A-28916-3ratio_946-710.jpg

The trick is that I didn't write any plugin =) I just made a "shadow" mesh that is just in front of the heatshield. The mesh is not "renderless" but rather has a full black alpha transparent texture so that the reentry effect would pick it up. The problem is that the stock reentry effects detects mesh edges, so if you are moving head on (prograde) you don't actually see anything, not even the ship's own effects (cause the bowshock model is blocking it).. The screenshots that you see were taken with spacecraft on it's side or going retrograde. That's why I say "it's not very correct" xD

There is another problem and that's that the reentry effect sometimes show on the ship, sometimes disappears completely, while at some times it's picture perfect.

If the reentry effect picks up normals for example (which I will test soon), I could trick it and make it better.

But of course, the mach angles shock changes are not possible cause the bow shock mesh is basically merged with the heatshield. On the other hand, an animation that is set to vary with spacecraft angle (and then made into a transform to orient correctly) or Mach number could be possible as you say.

Edited December 3, 2013 by nothke

[amo28]

Nathan, if I'm having solar panels break off on landers landed on Kerbin upon loading them as the active vessel, is that DR causing the issue? I noticed in your V4 release notes, you said you made some changes to fix a related issue. Is there anything in the config that I can change to lessen the effect?

[Sacred Aardvark]

Ran into a slight hiccup while doing an sub-orbital hop to the pole for giggles. I had KW rocketry fairings on the vessel, like I've had on all my ships for aesthetics since they haven't really gone up fast enough for it to matter in stock, however since I now had a lot more TWR and wasn't really worried about getting out of the atmo I went more horizontal, got more speed and figured I'll just throttle back if the flames start licking the fairings, which I realized was a bad idea when the parachutes on the payload inside the fairing overheated and blew up.

Further investigation proved that the fairing "is shielded", while the bits inside the fairing are blasting away through the shockwave they were supposedly protected from The KW-fairings are attached to a part below, so I'm guessing DRE isn't understanding where the actual cone bits are located because of it?

Anyhoo, long story short is there something I can do to fix the fairings functionality? (or can someone recommend a fairing mod that does work with DRE?) Thought about adding a heatshield module to the fairings, but since it already thinks they are shielded I'm not confident it would help. I seem to remember reading about a similar issue someone had and fixes being suggested, but a quick browse through the thread and didn't spot anything that would help and a quick google run just found someone else asking if KW-fairings could be made compatible with DRE, but no solutions that I could spot.

[AbeS]

Procedural Fairings are the best fairings ever! There are no limits! I have done something similar, went at like 4 km/s while in atmo (in RSS). The fairings blew up and after that what was inside started to overheat (and eventually blew up too )

[Sacred Aardvark]

Procedural Fairings are the best fairings ever! There are no limits! I have done something similar, went at like 4 km/s while in atmo (in RSS). The fairings blew up and after that what was inside started to overheat (and eventually blew up too )

Righto, off to install PF then

I think I chose KW back in the day, when I just wanted them for looks, because I figured it'd be more likely to work with mods than PF... I chose, poorly.

[LC NOoSE IV]

:mad:dude the configs for the heat shields aren't complete look thru them and please fix

[NathanKell]

FlowerChild: Thanks!

Yeah, especially these days when I'm a half-week behind on the MFS and ST updates I said I'd get out this weekend, the last thing I want to read is "add this!"

I'm happy to consider requests, although I do have to warn everybody that DRE is pretty low priority for me.* I just don't have time to rewrite it right now, so while I can add easy additions, and while I must fix big and harmful bugs...not much else at the moment.

*Fixing MFS/ST is now #1. Then I want to work on RSS again, and by then we'll be dealing with .23

Regarding ICBMs: You need a warhead that has a really high g tolerance, and also a really good heatshield.

LC NOoSE IV: dude I need more than that to go on lawl.

[LC NOoSE IV]

When I'm playing KSP career mode I try to find the heat shields for the two metre command pod and all I see are the decouplers for them. I looked thru the config files and I compared the one metre heat shield cfg with all the rest and I seen some parameters are missing. I don't know them off the top of my head, I'm on my school computer right now so I don't have the cfg's to tell you exactly what's missing from the files right now, but I hope you fix the problems that I'm having with the mod. I'm currently having to write my own pars. to fix it, works now. If it helps I am running on a 2011 MacBook Air with the latest update with OSX Lion. Please help.

[ExEvolution]

Does deadly reentry cause random Kraken attacks

[NathanKell]

LC NOoSE IV: either you have a bad install, or, like you always have to do when you add new parts to an existing career save, you have to go back to the node where the part is set, and unlock it yourself (In R&D). For the 2.5m shield, that's specializedControl.

ExEvolution: Can you use words (of a non-expletive sort) to explain exactly what happened? Your video is mostly in map view, then there's a boom, then there's fewer parts...?

[LC NOoSE IV]

I use a creative save for all my "works" it still wasn't there.

[FlowerChild]

FlowerChild: Thanks!

Yeah, especially these days when I'm a half-week behind on the MFS and ST updates I said I'd get out this weekend, the last thing I want to read is "add this!"

I'm happy to consider requests, although I do have to warn everybody that DRE is pretty low priority for me.* I just don't have time to rewrite it right now, so while I can add easy additions, and while I must fix big and harmful bugs...not much else at the moment.

Man, I've been heavily into this modding game (mostly Minecraft, just really starting on KSP) for quite awhile now, so boy do I hear you. I've been biting my tongue at a lot of the more demanding posts I've been seeing in this thread as a result, and I guess that one I responded to just happened to catch me in a particular mood.

Anyways, suffice it to say I greatly appreciate what you've been doing here, and am entirely sympathetic to a lot of the baggage that comes along with providing people with free content. Way too often "here's some cool stuff I made!" seems to only be responded to with "but I want it in blue!"

I've yet to go fully public with it (getting very close now, but I might wait for .23 since it sounds like it's coming soon), but DR has made an absolutely HUGE difference to the overall quality level of my own KSP mod through making it a required install to go along with it, and already a lot of people are getting a great deal of enjoyment out of it as a result. I'm extremely grateful for the work that you have put into making that possible.

[FlowerChild]

Ok, this has been a long time coming while I worked on balancing my own mod, but here's the custom config settings that I promised for people that want a more challenging DR experience with stock sized Kerbin and otherwise stock install. I've tweaked them to present a real challenge for those that find default DR values way too easy, while maintaining vanilla's "gamey" feel, and personally find them to fit in very well with the rest of vanilla KSP.

Just drop the following file into your Gamedata/DeadlyReentry folder and you're good to go:

Download Link

If you already have a custom.cfg file in that directory, you will likely need to delete it in order for these changes to take effect.

I've tried to balance it so that the 1.25m heatshield (and the Mk1 capsule integrated shield) are effective for reentry from low Kerbin orbit. 2.5m on a direct return trajectory from the Mun. 1.25 effective for small probes entering thin atmospheres (like Duna), and 3.75 effective for entry and aerobraking maneuvers in thick atmospheres like Eve or Jool. I've left the reflective heat shields at default values given they get rid of a percentage of the heat accumulation regardless of other settings. I will warn that I have not fully tested the 1.25 and 3.75 heat shields yet to make sure they really fill their roles, so they may require further tweaking down the road. I've tested the other values though many many times over to ensure they're capable of doing the job they're intended for.

For reference, here's the contents of the config file in question:

// config file to rebalance Deadly Reentry parts and stock parts with DR heat shields for stock game feel.

@REENTRY_EFFECTS[Default]:Final
{
	@shockwaveExponent = 1.09
	@shockwaveMultiplier = 1
	@heatMultiplier = 25
	@startThermal = 250
	@fullThermal = 1150
	@temperatureExponent = 1.03
	@densityExponent = 0.85
	@gToleranceMult = 2.5
	@crewGClamp = 30
	@crewGPower = 4
	@crewGMin = 5
	@crewGWarn = 300000
	@crewGLimit = 600000
	@crewGKillChance = 0.75
}

// Command Pod MK1
@PART[mk1pod]:Final
{
	@MODULE[ModuleHeatShield]
	{
		@dissipation
		{
			@key, 1 = 800 480
		}
	}
}

// 1.25m Heatshield
@PART[1.25_Heatshield]:Final
{
	@MODULE[ModuleHeatShield]
	{
		@dissipation
		{
			@key, 1 = 800 480
		}
	}
}

// Heat Shield for Mk 1-2 Pod
@PART[2.5_Heatshield]:Final
{
	@MODULE[ModuleHeatShield]
	{ 
		@dissipation

		{
			@key, 1 = 800 240
		}

	}

}

@PART[0625_Heatshield]:Final
{
	@MODULE[ModuleHeatShield]
	{ 
		@dissipation

		{
			@key, 1 = 800 640
		}

	}

}

@PART[3.75_Heatshield]:Final
{
	@MODULE[ModuleHeatShield]
	{ 
		@dissipation

		{
			@key, 1 = 800 60
		}

	}

}

Note that I've also reduced the visible threshold on the reentry effects from what they normally are in DR for more flamey goodness.

Keep in mind I've done this to present a good gameplay challenge in keeping with the spirit of my own mod, NOT for realism. If that's the kind of thing that you're personally looking for, then you may want to give it a try.

Edited December 5, 2013 by FlowerChild

[BC000001]

"2. Playing on Stock Kerbin, want realistic levels of heat on reentry (i.e. faking an 8km/sec reentry): set the shockwave exponent and multiplier to taste; I suggest exponent 1.12 to start. You will need heat shields built for RSS."

What is RSS and where do I find shockwave exponent and multiplier?

[jrandom]

What is RSS and where do I find shockwave exponent and multiplier?

Real Solar System

[ExEvolution]

I came out of a time warp to prepare for my burn, things exploded

[z26]

sorry if that already been said (not going to search 50 pages), but cubic orthogonal struts act as perfect insulators/shields, since they always stay at 0 degrees. probably because they are set as physicsignifiance=1, anyway not a big deal.

[wasmic]

I came out of a time warp to prepare for my burn, things exploded

What other mods do you have installed? It doesn't sound like it's a problem with DRE, and "things exploding when coming out of time-warp" has happened many times in this game. It might not be a mod that does it at all, but it might also be because of a mod.