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

[anxcon]

reading through the source of ModuleAnimate2Value to see if it would work for an idea I had

i noticed it updates the values in Update() which is every frame, not in FixedUpdate()

any reason for this? shouldn't it go in FixedUpdate()?

[Starwaster]

I noticed that after installing DRE all of the pats became unstackable in KIS containers. What list of modules DRE adds to parts?

ModuleAeroReentry is added to every part.

ModuleAnimate2Value is added to some animated parts (primarily to landing gear and shielded docking ports)

reading through the source of ModuleAnimate2Value to see if it would work for an idea I had

i noticed it updates the values in Update() which is every frame, not in FixedUpdate()

any reason for this? shouldn't it go in FixedUpdate()?

I don't know what the original reason was as it predates my 'inheritance' of Deadly Reentry.

But it's probably because animations themselves are graphical in nature and update every frame.

As far as the end application, I can see arguments for using either FixedUpdate() or Update() depending on what it needed it for. Leaving it in Update is probably safer even if it runs more frequently than if it only used FixedUpdate()

Edited September 20, 2015 by Starwaster
correction / clarifications

[Herrkurt]

Still doing RO. I just flew a plane with radial chutes mach 2 at 13km alt. The chutes were fine but the space plane type cockpit rated for sub-orbital and gentle LEO was on the verge of critical overheat. What's happening?

[Starwaster]

Still doing RO. I just flew a plane with radial chutes mach 2 at 13km alt. The chutes were fine but the space plane type cockpit rated for sub-orbital and gentle LEO was on the verge of critical overheat. What's happening?

It'll survive. Its skin reaches thermal equilibrium at a temperature that is hot enough to trigger the thermal gauges.

Unless you come in for reentry too steeply, you'll survive.

I just did a reentry from 200km in one of the OPT type J/K planes and nothing burned up, even though every gauge was lit up like a christmas tree.

[Enceos]

@Starwaster, does DRE tweak stock aerodynamics or engines in any way? My SSTOs with Ramjets and Rapiers lost 50% of their thrusting power in airbreathing mode with DRE... consequently not being able to reach Mach 3.

Another thing, the Inline Ballutes I made with Riocokite when deployed are starting to overheat and explode above 60km on Kerbin.

Do you happen to know what might be causing this behavior in DRE patches?

Edited September 21, 2015 by Enceos

[Starwaster]

@Starwaster, does DRE tweak stock aerodynamics or engines in any way? My SSTOs with Ramjets and Rapiers lost 50% of their thrusting power in airbreathing mode with DRE...

Another thing, the Inline Ballutes I made with Riocokite when deployed are starting to overheat and explode above 60km on Kerbin.

Do you happen to know what might be causing this behavior in DRE patches?

Deadly Reentry does not touch aerodynamics.

It doesn't do anything to engines aside from reduce their maxTemp if maxTemp is too high. However, it also reduces their heat production by a proportional amount to prevent them from overheating. None of that should affect Rapiers. Have you checked to see if the behavior goes away if Deadly Reentry is uninstalled?

re: ballutes. As above, DRE reduces maxTemp on parts if it exceeds a certain threshold. Ballutes are too new for DRE to be doing anything to them specifically. Have you checked that they survive those same conditions if Deadly Reentry is uninstalled?

[Herrkurt]

Starwaster- The temp gauge for the cockpit lit up on during most of the flight. What scared me is that going mach 2 at 13km sent it from green/yellow to deeply in the red to the point of only a sliver short of exploding. Can a plane not go beyond mach 2 when traveling at Himalayan altitudes in reality?

[Herrkurt]

Nevermind. The cockpit outlasts the engines when I push it closer to mach 3.

[Starwaster]

Yeah, I've tested space planes quite a bit with DRE designed around a thermal protection system equivalent to that of the shuttle. (high skin max temp; low skin thermal mass. Basically, shuttle tiles over aluminum: low internal maxTemp)

The skin max temp is very close to the the temperatures that you'll experience at high mach or shallow reentries so like I said, it triggers the gauges and it looks a bit scary but you really have to push it hard before something blows. I might buff the thermal mass a bit but so far, aside from stories like yours, nobody has actually had a problem with their planes blowing up, so I've held off so far.

One idea I've toyed with is to allow for the possibility of players switching from a shuttle style TPS to something like the SR71 where it's made of titanium and has very high thermal mass (at the expense of a more massive airframe). That would be done in the VAB via context menu and tie into ModuleAeroReentry

[NathanKell]

There's a bug in the gauge code, it checks the skin temperature (correct) vs the max internal temperature. Which leads to silliness if, as in RO, the skin temp can be up to 2000 K but the max internal temperature is 500 K.

As to reentry problems in RO, it's due to a bad physics patch in 10.4, I'll release an update shortly. Sorry.

[federicoaa]

I'm playing with RO and RSS, even from lunar reentry I only use like 4 units of ablator (and max G is ~7)

Is it normal or should I modify some setup?

[Starwaster]

I'm playing with RO and RSS, even from lunar reentry I only use like 4 units of ablator (and max G is ~7)

Is it normal or should I modify some setup?

As has been discussed before, shields configured under Realism Overhaul don't lose very much ablator. And that's by design.

[Jovus]

-snip original description of problems with reentry blowing up my craft, put here for easy finding-

I've gone back and verified that this problem persists on a completely fresh install of KSP using just FAR v0.15.5.1 "Hayes" and DRE v7.2.2 on KSP v1.0.4 x86_64 for Linux. (More information on precise Linux setup can be supplied if necessary.) Please let me know if you need more information or if you think I should be posting in the FAR thread instead/as well.

Reproduction steps:

1. Download http://kerbalx.com/Jovus/Reentry-Testing-Craft. This craft is the craft used for reproduction.
   
2. Get that craft into a 75km x 75km orbit. I prefer Hyperedit.
   
3. Activate the engine to bring the craft down to a 75km x 25km orbit.
   
4. Activate the decoupler.
   
5. Keep the craft pointed retrograde through reentry. It's a bit unstable, so you'll need SAS. For best results, don't just use the 'hold retrograde' setting, as that will drain battery too quickly. To make the problem appear more rapidly, use physics acceleration, but this should be unnecessary.
   

Player.log here

Edited September 23, 2015 by Jovus

[Starwaster]

I've gone back and verified that this problem persists on a completely fresh install of KSP using just FAR v0.15.5.1 "Hayes" and DRE v7.2.2 on KSP v1.0.4 x86_64 for Linux. (More information on precise Linux setup can be supplied if necessary.) Please let me know if you need more information or if you think I should be posting in the FAR thread instead/as well.

Reproduction steps:

1. Download http://kerbalx.com/Jovus/Reentry-Testing-Craft. This craft is the craft used for reproduction.
   
2. Get that craft into a 75km x 75km orbit. I prefer Hyperedit.
   
3. Activate the engine to bring the craft down to a 75km x 25km orbit.
   
4. Activate the decoupler.
   
5. Keep the craft pointed retrograde through reentry. It's a bit unstable, so you'll need SAS. For best results, don't just use the 'hold retrograde' setting, as that will drain battery too quickly. To make the problem appear more rapidly, use physics acceleration, but this should be unnecessary.
   

KSP.Log here

Are you aware that your craft's decoupler is actually its heat shield? You're separating your heat shield from your ship. Surviving that is going to be problematic with or without FAR.

Also, please do not ever present a KSP.log to me. I do not accept them. Logs must be either output_log.txt or (for Linux/Mac) player.log (Exceptions eternally: Absolute none.)

[Jovus]

My apologies. Both fixed in the original post, and I ran the test again with a completely fresh Player.log just to make sure. Craft: http://kerbalx.com/Jovus/Reentry-Testing-Craft Player.log: http://justpaste.it/nx8p

There were actually three files named Player.log; I picked the one from the Kerbal Space Program folder, rather than the unity3d folder or the Launcher folder. Let me know if you need either of the other two.

[Starwaster]

My apologies. Both fixed in the original post, and I ran the test again with a completely fresh Player.log just to make sure. Craft: http://kerbalx.com/Jovus/Reentry-Testing-Craft Player.log: http://justpaste.it/nx8p

There were actually three files named Player.log; I picked the one from the Kerbal Space Program folder, rather than the unity3d folder or the Launcher folder. Let me know if you need either of the other two.

I'm not aware of player.log being saved to the main KSP folder, but then I haven't played under Linux or Mac since KSP 0.9 and I think the Unity version changed since then so I don't know. As long as the timestamp is appropriate for the time period testing occurred in then it should be ok.

Now, I've run through a couple of reentries with your craft and I'm not seeing a problem so far. I'm repeating the test both with and without FAR to see exactly at what angle of attack things stop being occluded. (with stock, it happens somewhere between AoA 20-25 degrees except that the parachute stops being occluded much earlier)

I have a suspicion that your orientation might not be dead on. You're not using MechJeb so that means you're using stock SAS so you're keeping it oriented manually? (with MJ you can maintain orientation of exactly 0.0 AoA with very little electrical usage because stock SAS sucks and MJ doesn't)

Edit: Ok, with FAR installed, occlusion starts to end at AoA 3 degrees. That shouldn't be taken as an absolute figure; it could be more or it could be less for various parts on the stack. Check your angle of attack during reentry. FAR has an option to display that. Click the FAR button then Flt Data. Look for Angle of Attack and Sideslip Angle. The further those are from 0, the more exposed your parts are going to be. I'm betting that's why you're seeing heating and it's probably by design as FAR is supposed to be a more realistic aerodynamic model. Believe it or not, in real life, you wouldn't see 100% occlusion on those parts either. Hot gasses would be slipping up the sides and scorching them. Even hitting the sides of the capsule, though heating would not be as severe because the shockwave expands and cools once it slips past the blunt end but even the sides have to be shielded to some extent. So frankly, you've got it pretty easy in stock as far as reentry heating goes.*

Edit #2: *And that includes Deadly Reentry seeing as how DRE only tweaks stock heating; it no longer decides what gets heated or by how much.

Edited September 23, 2015 by Starwaster

[Jovus]

Edit: Ok, with FAR installed, occlusion starts to end at AoA 3 degrees. That shouldn't be taken as an absolute figure; it could be more or it could be less for various parts on the stack. Check your angle of attack during reentry. FAR has an option to display that. Click the FAR button then Flt Data. Look for Angle of Attack and Sideslip Angle. The further those are from 0, the more exposed your parts are going to be. I'm betting that's why you're seeing heating and it's probably by design as FAR is supposed to be a more realistic aerodynamic model. Believe it or not, in real life, you wouldn't see 100% occlusion on those parts either. Hot gasses would be slipping up the sides and scorching them. Even hitting the sides of the capsule, though heating would not be as severe because the shockwave expands and cools once it slips past the blunt end but even the sides have to be shielded to some extent. So frankly, you've got it pretty easy in stock as far as reentry heating goes.

That squares with my experience, I think. I'll ask the FAR gurus if they think that's reasonable behaviour and redesign my rockets if so. My one further question has to do with the Mk1 pod exploding before the Science Jr. Why is that the case? I would think that the pod should have more thermal mass than the experiment, but maybe that's not the case? Thanks for all your help.

[Starwaster]

That squares with my experience, I think. I'll ask the FAR gurus if they think that's reasonable behaviour and redesign my rockets if so. My one further question has to do with the Mk1 pod exploding before the Science Jr. Why is that the case? I would think that the pod should have more thermal mass than the experiment, but maybe that's not the case? Thanks for all your help.

Its total thermalMass is higher than the Science Jr, but it's skin is actually somewhat lower. (at 5.2 vs 6.5)

I'm guessing it's more to do with it being higher up the stack so it's going to be more exposed when it actually gets exposed. But that's just a guess.

[Jovus]

Dropping Ferram's reply here because it seems relevant to your interests:

@Jovus: Well, I was able to reproduce the issue, which is very, very simple: DR is excessively punishing towards command pods if they have any bit exposed to the airflow, and FAR ends up exposing a little bit to the airflow through the one little piece of ladder on the side, but a lot more through the lip formed by not pushing it down closer to the part below it. Yeah. That ended up being enough to kill it when combined with the really narrow heat shield. You gave a way for hot plasma to get right up against the vehicle and then bad things happened.

So it sounds not so much like a bug (in the sense of malfunction) as (possibly) a call for different usability parameters. Not that I'm expecting you to change your calculations for my sake, just that I thought you'd want to hear Ferram's opinion because it pertains to the issue. Meanwhile I'll be changing my rocket designs. Thanks again for your help!

[Starwaster]

Dropping Ferram's reply here because it seems relevant to your interests:

So it sounds not so much like a bug (in the sense of malfunction) as (possibly) a call for different usability parameters. Not that I'm expecting you to change your calculations for my sake, just that I thought you'd want to hear Ferram's opinion because it pertains to the issue. Meanwhile I'll be changing my rocket designs. Thanks again for your help!

The thing is, when it comes to heating, DRE doesn't do much other than tweak stock values. That's interesting about the ladder, I wouldn't think it would matter much.

I think another factor is that the capsules (because of their shape) have less surface area, which affects skin mass which affects skin thermal mass. That's why the pod has slightly less thermal mass than the science part even though it's 4x heavier than the science part..

I could maybe bump its thermal mass up a bit. That doesn't sound too OP. In your case I don't think it would help that much except to delay the inevitable. You could also add back some of the ablator that you removed (5-10 pts would probably get by) but that won't save the science part. I think ultimately you need a bigger shield, or use an aeroshell made of Procedural Fairing and add some ablator to it. (e-dog's fairing parts, not the stock ones which throw errors when shields are added to them). Just right click the fairing piece and you'll see you can add ablator to it. Make a reentry vehicle out of that

[Redneck]

Humm I wonder how this will work with the deltaglider xr-1. She tumbles uncontrollably if you deviate at all during reentry. Im thinking its due to no heatshield being implemented as of yet

[Starwaster]

Humm I wonder how this will work with the deltaglider xr-1. She tumbles uncontrollably if you deviate at all during reentry. Im thinking its due to no heatshield being implemented as of yet

What exactly are you thinking the relationship is between heat shielding and aerodynamics is?

Because I see none. None whatsoever.

Either the the aforementioned craft does not have its aerodynamics properly set up or its tumbling should be considered a natural consequence of deviation, or both. (every aircraft is capable of being put in situations where it becomes uncontrollable or requires special recovery procedures performed to regain control)

Edit: I see that DG is your mod. Are you making use of CoLOffset / CoPOffset in any of your lift / control surfaces? If not, then have a look at how that's done in stock parts and give some thought to doing that for your parts.

Edited September 28, 2015 by Starwaster

[Redneck]

Thanks for the tip ill look into that

[Enorats]

So, I recently began using Deadly Reentry as part of the Realism Overhaul and Real Solar System bundle. I'm having a great time with the whole thing.. but I'm also having some real problems. The heat might eventually be one of them.. I just had a heat shield literally melt, though oddly enough my capsule survived. My real problem however is my Kerbals turning into a greenish paste upon contacting the atmosphere. The g-force meter just flies straight up and anyone in the craft goes smoosh within seconds of beginning reentry.

Currently I'm just starting out in this game, and I've been doing all I can to gain science and unlock various parts. I started out with purely in atmosphere launches and those went okay. After going higher than around 120 km (almost to space, 130 km) all of my crafts began experiencing this g-force problem. It only gets worse the closer I get to actually achieving orbit. I just had a craft make it about 1/4 of the way there and was travelling around 5500 when it hit the atmosphere and Val just instantly went smoosh. Then the entire thing just vaporized a moment later. Is that really how it works? Are suborbital flights ridiculously more dangerous than actually achieving orbit? That just doesn't seem right to me.

Is there some way to reduce my g-force effects on a suborbital flight? I mean, I'm smooshing kerbals without ever leaving the atmosphere..

[Starwaster]

I wouldn't say sub orbital is inherently more dangerous but it can be depending on circumstances. A reentry from orbit, while faster, will be on a path that allows plenty of time to brake while in the upper atmosphere. A very steep sub orbital on the other hand might not allow enough time for aerobraking.

So you could end up hitting very dense layers of atmosphere at hypersonic speeds and suffer lethal amounts of G forces, or heat up faster than your heat shield can withstand. So if you're sub orbital, make sure that your trajectory still allows for a shallow reentry. (note that even ICBMs have to be heat shielded or the warheads won't survive reentry)

Also, make sure that your engines aren't too powerful. They should be starting with a TWR somewhere between 1.2 - 1.6. If necessary (and if your engines allow it) then throttle back if the G force meter goes too high.