[0.20] Deadly Reentry 2.3 - reentry heat, plus thermal and g-force damage to parts

[Killerblonde]

No but fairing factory can be used in a pinch.

The original deadly reentry had some pretty nice heat shields with it. With a bit of fiddling around with cfg files I'm sure they could be modded to have a lower max temp and some ablative coating.

[White Owl]

So combining this with ModuleManager, it should be possible to change other mod parts to work with your directional heat shield? Like B9 Aerospace, for example?

[gabmaia]

Okay, so i did a little bit of testing and.... Couldn't get anything to explode! I came in in speeds up to 3km/s in a variety of angles with plenty of different spacecraft, from a single probe up to 3 orange tanks, and couldn't get any of them much hotter them 1000º. What am I doing so right?

[astocky]

So combining this with ModuleManager, it should be possible to change other mod parts to work with your directional heat shield? Like B9 Aerospace, for example?

Correct. The text you need to add to the part is (taken from the Mk2 Fuselage:

MODULE

{

name = ModuleHeatShield

direction = 0, 0, 1 // underside of fuselage

reflective = 0.05

ablative = AblativeShielding

loss

{ // loss is based on the shockwave temperature

key = 450 0 // start ablating at 450 degrees C

key = 550 2 // peak ablation at 550 degrees C

key = 3000 2.5 // max ablation at 3000 degrees C

}

dissipation

{ // dissipation is based on the part's current temperature

key = 300 0 // begin ablating at 300 degrees C

key = 500 180 // maximum dissipation at 500 degrees C

}

}

RESOURCE

{

name = AblativeShielding

amount = 100

maxAmount = 100

}

If you add that to the part.cfg it will configure the parameters it needs. You will also probably need to halve the maxTemp of the parts though to line up with what the mod expects now.

[astocky]

Tested and seems to work great on the first try. Using KSP 0.20 FAR 0.9.4.1 and DR 2RC2.

Here is a video with the details:

http://youtu.be/p7LZR2E5LPE

Details are Orbit 155km x 158km. Retro until periapsis 0km. Skip to 24:00 in video for the reentry part. Hit 70km @ 2313m/s. Hit 35km @ 2143m/s. Temp peaked at 540C. Ablated all heat shield.

Let me know if you want me to run some more trials.

Edited May 29, 2013 by astocky
Listed versions used

[astocky]

Ok I tried some more reentries and could not get the temp to rise above 590 (that was returning from Mun orbit to 27.5km PE). I also entered from almost escape orbit (just outside of Minimus) and hit atm @ 3320m/s and went sideways most of the way (please don't ask why). Nothing exploded - didn't even fully ablate the heat shield.

[Sherrif]

I just launched about 800km off the surface and dropped strait down at like 3km/s with landing legs attached to the side of a mk1. The only heat failures that happened was that my parachute opened without me telling it to, but the chute stayed in tact and allowed me to land safely.

[astocky]

One last test just to see if I could die. I created a loop just out past minimus and then accelerated in towards kerbin.

27deg reentry angle (no orbit)

100km @ 3962m/s

70km @ 4022 m/s

15+ g's of deceleration

>1000C peak temp

150ish heat shield left

take 2

60+deg reentry angle (no orbit)

100km @ 3900m/s

70km @ 4000 m/s

15+ g's of deceleration

peak temp caused explosion

220ish heat shield left (when i exploded)

[dorin6565]

You may want to look at this page for the temperatures behind a normal shock wave.

https://en.wikipedia.org/wiki/Normal_shock_tables#Normal_shock_table_equations

These are good until you get to 2000kelvin where real gas effects start to occur. The equations only depend upon the free stream Mach number and the ambient temperature of air at that altitude. The heat transfer will then be related to the difference between the temperature behind the shock and the temperature of the heat shield. Also the density.

[taniwha]

I am pleased to state that SSTO space "planes" (anyone who's seen my VSSTO will understand the quotes) are still quite possible. I lost over 60% of the ablative heat shield on the Mk1 cockpit during ascent due to a tumble (fell, and overheated after recovering), but I got into orbit (80x75) without any other problems. I came down on an 80x40 orbit, got a bit of flames around 27km, burning off the remainder of the heat shield, but no part exceeded about 540 degrees (lower, forward fin: it and the belly mounted chute were always the first to go in DRE 1.3).

I haven't tried to burn anything yet because with the talk about long reentries causing more heating, I was worried about space planes, but now I know that they're fine with due care. Now on to the fun }:>

PS: one bug I noticed: the cockpit has "is Shielded" listed twice in the right-click menu.

For those complaining about reentry being too easy: while it might be a bit too easy, remember that Kerbin is meant to be for getting ones feet wet and thus not too difficult. I'm sure Eve or Jool will be more challenging .

[stupid_chris]

Why does the three man pod have no heat shield?

Also, as said multiple times above, getting in at extremely steep angles seems to make the reentry a lot easier. I think to prevent this you should add a simple script that makes it like that 12G+ destroys the parts. I know objects don't spontaneously explode at 12G, but it would make it much more realistic, which I think is the goal of this mod. I know the goal of this is to manage temperature, but if then people just decide to make straight drops to survive, this just makes it all useless. And external heatshields would be interesting. Example: having a heatshield under your craft for an aerocaputre around Jool. Anyway great work, noticeable improvements from the previous version for the ablative protection and the temperature management ^^

[aquilux]

The way endless and I were trying to manage this in the bit of code he worked up for ablative heat shields under the prior version, was to just have the burnoff rate and efficiency of an ablator that actively dispersed heat, tied to the heat shield's temperature (though I had initially thought to use a more direct drag factor).

As the shield got hotter the ablator would burn off faster and in the process dump more heat, but it wouldn't quite keep up. If you tweaked the settings right, you could make it so that too aggressive of a reentry built up enough heat to blow the shield, and then boom! Also, even if you kept the descent below overheating, if you tried to reenter from too far away (see "too fast") you'd burn through your ablator too soon, and then there'd be nothing to protect you from re entry, and then boom as well.

Here is the thread, if you want to look over what we have accomplished.

[aquilux]

Ah, so I actually spent some time looking over this and I see that is in fact what you have done. Chris, just tweak the settings until the shield protects the pod from, let's say, a 3g reentry, but just barely. (use mechjeb to calculate it, re enter manually with mechjeb giving you it's predictions) Any steeper of a reentry will generate more heat than that, and it'll go beyond what the shield is capable of and your parts start hitting their max temp values.

Boom boom POW, there goes the ill fated ship.

[aquilux]

Just watched your video, and I take exception to the high altitude deceleration being wrong.

about the apollo CM reentry profile. Notice "the skip" to keep the "heating load" down. Also, aerodynamic control is something I'm still hoping someone adds in.

[cparen]

1.3 was way, way more harsh than it should be. In 1.3 and earlier, the effective temperature of the shockwave was infinite - so you could explode at almost any speed if you didn't decelerate fast enough.

In 2.0, the temperature is capped by the velocity, so as long as you are going under 2 km/s you'll get a lot of pretty lights but nothing will explode.

Agreed. Let me first say, it's awesome to see that DeadlyReentry is still being developed!

I'd like to point you to some tweaking I was doing on DR 1.3 -- just as a reference point, as I'm curious what you might like to do with it. I captured a some reentry data, speed-altitude profiles for various reentry angles (all from the same starting apoapsis). That might be of some use to you.

I also tried controlling heat diffusion per atmo density, but got nowhere with that approach; unfortunately, the stock cooling effects tends to cancel out the heating too strongly.

Then I tried out picking polynomials that projected the desired heat response per the reentry data set. I found the best result at about V^4.5 * P^1.5. This resulted in a fast onset of reentry heat as insertion angle increased, but a slow onset of heat in the close-but-fatal angles. You can see an example of that here: (youtube).

Specifically, I desired that, from 100km apo, (a) reentry angle (pitch at 33km) between 0-5 degrees is always survivable ( up to 9 degrees survivable with heat shielding. © spaceplanes can take off from ground and acheive orbit without any part failing, and (d) spaceplanes can reenter using lift to extend upper atmo deceleration, e.g. space shuttle type S-turns. My current git repo achieves these goals, but it's still far from perfect.

Does DR 2.0 have source available somewhere? I'd love to take a look. Otherwise, I'll try it out tomorrow. I'm glad to see this mod being improved :-)

[nothke]

Hello guys! Interesting thread. I was working on a mod that adds TPS tiles and rC-C leading edges similar to the one used on the shuttle which you can place on the hull, and also replace them if they are damaged. I have since left the project to work on other stuff, never publishing anything, but I will soon make a vid about it.

Deadly reentry 1.0 worked perfectly with it =)

Edited May 29, 2013 by nothke

[RoboRay]

But OMG, the part count!

[nothke]

But OMG, the part count!

Not a lot, there are different sizes. Only the ones around the cockpit (yellow ones) are single tiles. The blue and green ones are multiple tiles combined into larger parts. I also planned to make even bigger ones to reduce part count as much as possible. But only the yellow ones are portable in EVA, so if you brake a blue one you'd have to fill it with many yellow ones.. Or just decide not to use the craft for landing. The tiles are very breakable by the way (low impact resistance) just like the real ones. Leading edges and the nose cone especially (seen in second screenshot)

Edited May 29, 2013 by nothke

[astocky]

Just watched your video, and I take exception to the high altitude deceleration being wrong.

about the apollo CM reentry profile. Notice "the skip" to keep the "heating load" down. Also, aerodynamic control is something I'm still hoping someone adds in.

I hope it wasn't my video you were talking about. The first part of the video was doing a comparison of the old version (that didn't work properly) then the new version that works much better. I also don't think that the high altitude deceleration you are talking about in the video is KSP relative. The Apollo capsule hits the dense atmosphere then raises back up; that is not the same as setting a high PE and decelerating in the thin atmosphere. The video indicates they get to 2.5g before pulling up. In KSP if you hit 2.5g you have pretty much stopped already.

I do think though that the atmospheric model is still not 100% even with FAR. But with deadly reentry 2, at least the reentry effects are modeled quite well based on the imperfect atmosphere.

[gabmaia]

Man, I know it would be very complicated, but would it be possible to make a ablative "paint"? My humble idea is to use ModuleManager do modify a part's proprieties before loading, but i have no idea if it can be done

[Awaras]

Man, I know it would be very complicated, but would it be possible to make a ablative "paint"? My humble idea is to use ModuleManager do modify a part's proprieties before loading, but i have no idea if it can be done

You mean something like the idea posted here:

http://forum.kerbalspaceprogram.com/showthread.php/31565-Decal-Heat-Shielding

[Black-Talon]

Really impressed with the continued effort here. And the focus on realism is impressive and appreciated!

I see many people are concerned with the lack of "Deadly"-ness in a steep and very fast fall. Perhaps this is too big a departure from scientifically correct physics...but for me I know it would add a lot to the game if two simple conditions were true:

1. Any 'men' on board die if the G-Force meter is anywhere but in the Green section
   
2. All parts explode, even on an unmanned craft, if the G-Force meter ever hits the Red section
   

While not necessarily correct in all cases, this would provide a simple model for reentry failure on a high-speed, excessively steep, reentry. I think it fits extremely well with the theme of this mod as well. "Death" from "Deadly Reentry" can be caused by more than just heat after all!

Thanks for the great mod!

[Netris]

[*]Any 'men' on board die if the G-Force meter is anywhere but in the Green section

[*]All parts explode, even on an unmanned craft, if the G-Force meter ever hits the Red section

The green zone stops at about 2G. Nobody dies until about 10G for about 1 minute. You could even take 20G for 6 seconds acording to NASA

[nothke]

The green zone stops at about 2G. Nobody dies until about 10G for about 1 minute. You could even take 20G for 6 seconds acording to NASA

That's true, survivabilty depends on g force and exposure time, sorta like exposure to radiation.

Here's an (average person) graph of survivability, as you can see it depends at what direction the force acts

(the full article)

it would be very nice to include it! The red bar is more like "warning high g".

Only.. wouldn't it be "deadly everything" not just "reentry"?? xD

Edited May 29, 2013 by nothke

[Killerblonde]

My two cents are that there are already enough inaccuracies with KSP, such that any attempt at a 100% realistic reentry mod would end up being way to easy to reenter. (For example - orbital velocity is a LOT slower in Kerbal.) As such, the end should justify the means. The end should be a mod that makes reentry challenging and realistic at a glance, even if it involves fudging a few of the numbers or equations.