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

[drtedastro]

MAX-Q, Damn MAX-Q.......

[dlrk]

Can anyone advise on how to make new heatshields? I'd like to modify the Planetes inflatable heatshields for DR3 and RSS.

[Razorcane]

Why do you think going up should cause less heat than going down? Heating depends on velocity and atmospheric density, not direction of travel.

The solution is simple - don't go that fast low in atmosphere.

Perhaps it's a mods' doing, but a few of my rockets have to accelerate to that fast before they drop their boosters, in order to ensure orbit insertion. The re-entry effects only appear right as I transition between the first and second layers of the atmosphere, and my speed is usually ~1000m/s.

[asmi]

Perhaps it's a mods' doing, but a few of my rockets have to accelerate to that fast before they drop their boosters, in order to ensure orbit insertion. The re-entry effects only appear right as I transition between the first and second layers of the atmosphere, and my speed is usually ~1000m/s.

Well in this case you'll have to redesign your rockets so they won't go that fast... The point is - DRE works as designed, there is nothing wrong with heating on ascent - as I've said before heating is going to be the same no matter which direction you're travelling. That's actually one of the reasons rocket accelerate slowly in the beginning. Second reason being minimizing aerodynamic stress. Something tells me you don't use FAR - as otherwise your rockets would be torn apart by aerodynamic stresses.

[Tery215]

Is there a list of planets and moons in ksp, somewhere online or someone can provide, that gives me an idea of each one of their Deadliness I guess for reentry. Like something in advance before traveling there, I can prepare my landing parts with heat shields or not. I am fairly a noob with this mod.

I'm quite sure the deadliness of reentry for planets is based entirely on their air pressure. Put one of those barometers on your ship and it'll tell you the pressure.

[Taki117]

As the user before me, I am also a noob at this mod. I have the following problem: Deadly Reentry is too deadly for m! Whether I come in to the atmosphere of Kerbin with only a MkI capsule and a heatshield or with some science stuff attached, I always explode.. (And yes I am pointing my shield to 'the flames'.).

I come in from a 100-120km orbit with a periapsis of about 22-30km. Scott Manley did this in his latest video series as well, and he managed to "not explode".. Still, when I reach around 25-30 km altitude (about 2000 m orbital velocity) my shield overheats and blows up. The temperature is about 1000 degrees Celsius then.

My question: Am I doing something wrong (angle or something like that) or I the mod somehow set wrong in my game?

If I am doing something wrong, can you then suggest me what to do to make it work? I really like a challenge, but this I cannot do.

Thanks in advance.

Sounds like you need to come in shallower. I usually find that if my Pe is about 32km up and I am doing no more than about 3.2km/s I am fine (Might get a few reentry effects, but nothing super) This may not be realistic, but it works, is you could deploy your parachutes super early (like stage them in space) and that will slow you down considerably.

On an unrelated note I am having an issue when going to a ship from the Tracking station of parts overheating and exploding. (On the mun!) or whenever something goes wrong and I revert to launch (before physics kicks in) is this being looked into or has this been resolved and I need to update?

[AbeS]

The exploding thing while loading a vessel is being looked into, Nathan said so a couple of pages ago I think

[Maxwell Fern]

Here is a picture that sums up the problems I have. It's been taken when reentry visual effects just started. I'm using DREC and FAR.

-It's overheating, but is actually cooling down

-The ablative shield just started to deplete.

-There were landing gears on that ship, and they burned up way before reentry effects started

-I have SWE set to 1.08, and am using stock size Kerbin.

I really do love this mod, but it doesn't make a lot of sense. Can someone please tell me how to tweak it so I can have a realistic behavior with FAR ?

[ferram4]

Take a look at how much stuff you're trying to bring down, and then take a look at the size of your heat shield. According to Flight Engineer, you're trying to bring down a vehicle that is 3/4 the mass of a 3-man pod, but using a heat shield with half the diameter, which corresponds to 1/4 the cross-sectional area. So this means that your ballistic coefficient (a nice measure of how much mass your vehicle has compared to its drag) will be 3 times as high as that for the 3-man pod; you want that number to be as low as possible for reentry. It may not be possible to bring that vehicle down, since it's too massive for the amount of drag you've given it, which is realistic behavior.

If you're wondering why the landing gear burned off, it's because they weren't designed for reentry heating, and you didn't slap on a heat shield capable of covering them.

Another thing is that you've taken a relatively steep trajectory, considering you're at 25km and still moving at 1.9 km/s, with a good portion of it downwards. This basically means that you're not taking advantage of whatever drag you can while the atmosphere is too thin to actually heat up the heat shield dramatically.

[Kulebron]

By the way, from what I read somewhere, reentry is balancing between quick deceleration and flying in thin atmosphere, but burning up because the air particles heat up (air molecules hitting at 8km/s is equal to gas being as hot as 4500K-4900K). Is this true?

[Sentmassen]

So awhile back I edited some of the parts and made some custom textures.

here you see the texture at work, making it blend better with stock KSP

Here we have the decoupler attached to the heat shield. Before, you would see the heat shield clipping through the sides of the decoupler. Not anymore, i achieved this by making the heat shield just a hair smaller and the decoupler a hair bigger.

and here we have a the big decoupler. I tried to get a separate texture for the big and small decoupler but I couldn't get it to work so I went with the texture I liked more. It also makes a great general decoupler when one compares it to the garish stock ones.

Both decouplers have been slightly changes in scale and where the top and bottom attachment node sits, all for aesthetic reasons . Also the the heat shields have altered heat dissipation which works with my shockwaveExponent set to 1.15 on STOCK ksp planet scales, so keep that in mind.

download:

https://dl.dropboxusercontent.com/u/15214821/DeadlyReentryretexture.zip

[Kulebron]

Can someone explain what the tweakable values mean? Or at least can cooling (or heating up to ambient temp.) speed be tweaked?

[Lewiskerbington]

I dont know if anyone else is having this problem, but the parts won't show up in the tech tree for my career saves. (I'm using remote tech, interstellar, and tac life support, and all the parts for these mods show up)

[NathanKell]

Kulebron: yup.

Sentmassen: Wow, nice! Mind if I make them official?

Also, PM me the different textures (or post 'em) and I'll make them work.

Lewiskerbington: If you added it after you unlocked the nodes they're in, you have to go back to those nodes and unlock the new parts.

[Lewiskerbington]

If you added it after you unlocked the nodes they're in, you have to go back to those nodes and unlock the new parts.

No I started a new save file after installing all the mods. Could it be that I misplaced the manager.dll file (I just stuck it in the gameData folder along with everything else)

Edited November 24, 2013 by Lewiskerbington
Silly mistake

[Sentmassen]

Sentmassen: Wow, nice! Mind if I make them official?

I was hoping you would.

here is the texture I was trying to get working for the smaller of the two decouplers:

https://dl.dropboxusercontent.com/u/15214821/decoupler.png

Its simpler to go along with the fact it is a smaller part, but it has darker edges so that it should match better with the smaller tanks.

[Maxwell Fern]

Take a look at how much stuff you're trying to bring down, and then take a look at the size of your heat shield. According to Flight Engineer, you're trying to bring down a vehicle that is 3/4 the mass of a 3-man pod, but using a heat shield with half the diameter, which corresponds to 1/4 the cross-sectional area. So this means that your ballistic coefficient (a nice measure of how much mass your vehicle has compared to its drag) will be 3 times as high as that for the 3-man pod; you want that number to be as low as possible for reentry. It may not be possible to bring that vehicle down, since it's too massive for the amount of drag you've given it, which is realistic behavior.

If you're wondering why the landing gear burned off, it's because they weren't designed for reentry heating, and you didn't slap on a heat shield capable of covering them.

Another thing is that you've taken a relatively steep trajectory, considering you're at 25km and still moving at 1.9 km/s, with a good portion of it downwards. This basically means that you're not taking advantage of whatever drag you can while the atmosphere is too thin to actually heat up the heat shield dramatically.

Thanks for your answer, which makes perfect sense regarding temperature.

However, unless I misunderstand how ablative works, I find it illogical that my ship first heats to the point of overheating, THEN, when it starts to cool back down, my ablative shield only starts to deplete.

Isn't ablative shield supposed to ablate proportionnaly to heat ?

[Sparker]

I like this mod but I think that it would be awesome if we could add thermal protection to other parts in-game, because now adding a heat shield is the only efficient way to protect something from overheating.

What does 'active heatshield' mean? Some parts are said to have it built in.

[ferram4]

@Maxwell Fern: Based on what I've seen, the ablative shields do ablate proportionally to the heat being applied to them. The heat transferred to the shield increases greatly as it drops through the atmosphere, so greater ablation happens lower in the atmosphere. Further, ablation should coincide with the heat shield's temperature dropping, since the material that has ablated away is pulling large amounts of heat away from the shield.

@Sparker: "Active heatshield" means that the part will not absorb all of the reentry heat applied to it; normally if some type of ablative material isn't listed there that means that it's a heat-soak type of system, which simply reflects / absorbs as much heat as it can without transferring it to the underlying part.

[NathanKell]

High up, there isn't enough heat flux and atmospheric density to start ablation. Once the shield really starts ablating, as Ferram says, then the temperature drops (that's the point).

In other news, I have good news and bad news.

The good news: I finished an update to DRE. I fixed the explode-on-launch/switch bug.

The bad news: the click bug is totally reproduceable in pure stock KSP, and also happens on reentry flames. You don't even need a part to explode....also, while I finished the update, I fell asleep. I'll post today.

[andqui]

I'm currently trying to use deadly reentry with RSS for the first time- I'm trying to deorbit a probe, with a 0.65 meter heat shield attached. I'm using RSS, the Realism Overhaul, and the Real Progression lite tech tree tweaks. The heat shield is protecting everything behind it (they don't heat up much while reentering). I'm coming in with a perigee of 70 km or so, at a speed of ~7500 m/s. The problem is that the heatshield itself overheats and explodes when I'm at around 40-35k meters. I have plenty of "Ablative coating" left, but the temperature of the heatshield climbs too much and the shield fails, leading to the rest of the probe failing. Is this working as designed? Shouldn't the heatshield not overheat if the coating is still present, since the energy would be put into tearing the coating off rather than heating the shield core?

Should I be doing anything differently? I can't really slow down much more- did I come in too shallow, resulting in too gradual deceleration and too much prolonged heating? Is there a different perigee altitude I should use? I'm afraid that if I come in steeper I'll either not slow down in time or pull too many G's in reentry.

thanks

[Chebalu]

One of my favourite pod is the kosmos va capsule. Is it possible to add a "built-in heatshield" for this vessel? I don't know anything about programming so I appreciate if somebody could help!

[SZDarkhack]

Should I be doing anything differently? I can't really slow down much more- did I come in too shallow, resulting in too gradual deceleration and too much prolonged heating? Is there a different perigee altitude I should use? I'm afraid that if I come in steeper I'll either not slow down in time or pull too many G's in reentry.

I'm not an expert on DRE or anything, but you might want to come in a bit more steeply. I think the problem here is that, although the shield is heating up, there is not enough density to really get the ablation going (refer to Nathan's post above). Try a perigee of around 35k-45k from LEO. Around that value you get a maximum of around 8G deceleration (which the probe should be able to handle comfortably, even a manned capsule is fine with it).

For a more technical explanation of the issue, an ablative heatshield isn't supposed to insulate the craft from the heat, but rather remove heat via ablation. If the ablation doesn't happen fast enough to remove the heat, it will flow through the shield and damage it (and the craft).

[FlowerChild]

The good news: I finished an update to DRE. I fixed the explode-on-launch/switch bug.

That's VERY good news indeed man. Congrats on figuring that one out

The bad news: the click bug is totally reproduceable in pure stock KSP, and also happens on reentry flames. You don't even need a part to explode

Out of curiosity, what are the steps to reproduce this one in stock?

Edited November 25, 2013 by FlowerChild

[NathanKell]

FlowerChild: Thanks. Here: http://bugs.kerbalspaceprogram.com/issues/1806#change-6603

A note regarding the 0.625m shield. An early version of Realism Overhaul failed to include the RSS config for it. That also might have something to do with the problem...