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

[SmarterThanMe]

Nope.

Burned up with periapsis at 20km, -20km, -100km... Anything I can do to debug and figure out what's going on?

[Gryphon]

Nope.

Burned up with periapsis at 20km, -20km, -100km... Anything I can do to debug and figure out what's going on?

if you go into debug, under the Physics tab there's a Thermal tab. You can turn on debug colors and detailed thermal info on the right click menus for each part. If you look back a couple pages in this thread, you will see the explanations for which type of heating displayed there is which. This should let you see what is heating up, and where it is coming from.

[Recon777]

Adjust your peri within the atmosphere to taste(until you don't explode).

Use Alt+F12 -> Physics -> Thermal -> Display Termal information in menus and check how hot the parts get.

The US pods may be overheating, you need to adjust your Pe within the atmosphere until you find an angle where you don't burn out.

3000 m/s or so is normal for Minmus return(+/- 200m/s) and I've never had a problem with US pods burning up (Make sure you update US, not only DRE, FAR too if you have it).

Also, post an output log, which for Windows is located in KSPinstalldir/KSP_Data/output_log.txt.

When you hear/see and explosion press F3, which will pause the game and bring up a log of all flight events, where you will be able to see what exploded and why right away.

Are you using the latest version of DRE from last night? The previous version went through many iterations, mostly distributred via direct links to cfgs and dll files by Starwaster, some of which you may have missed.

Wow, thanks. That looks like a lot of good info. I'll see if I can make it work. Maybe I went in too steep, but I set up my Pe from the Mun's orbit, not correcting it after. If I recall, it was 20km or so. Is it a good strategy to bleed off speed by entering the upper atmosphere and then skipping back into orbit for another pass?

Edited May 30, 2015 by Recon777

[Starwaster]

Wow, thanks. That looks like a lot of good info. I'll see if I can make it work. Maybe I went in too steep, but I set up my Pe from the Mun's orbit, not correcting it after. If I recall, it was 20km or so. Is it a good strategy to bleed off speed by entering the upper atmosphere and then skipping back into orbit for another pass?

IRL it would be but the mechanics of Kerbin are by necessity different. You don't have enough ablative shielding for a move like that

(and by necessity I mean, in order to make it 'Deadly')

[Svm420]

I noticed when using the latest realFUels that my jet, at least so far, are not getting hot when running. I thought this may be casued by the ModuleEnginesRF RealFuels uses may not be seen by DR? OR there may be some other interaction just wanted to give a heads up for compatibility. Still wondering what settings I should play with to balance a larger kerbin and faster re entry to the tune of 4500m/s. Thanks!

[Starwaster]

I noticed when using the latest realFUels that my jet, at least so far, are not getting hot when running. I thought this may be casued by the ModuleEnginesRF RealFuels uses may not be seen by DR? OR there may be some other interaction just wanted to give a heads up for compatibility. Still wondering what settings I should play with to balance a larger kerbin and faster re entry to the tune of 4500m/s. Thanks!

I'd think that's better than the flip side of that which is people complaining that their jets keep burning up.....

[SmarterThanMe]

I figured out what my problem was... Lost power during reentry, therefore lost SAS control. Couldn't maintain the correct angle of attack, and therefore burnt up. Need more batteries.

Want to add this to your FAQ?

Edited June 1, 2015 by SmarterThanMe

[Starwaster]

I figured out what my problem was... Lost power during reentry, therefore lost SAS control. Couldn't maintain the correct angle of attack, and therefore burnt up. Need more batteries.

Want to add this to your FAQ?

I'll think about it but I'm not inclined to on the grounds that it falls under the purview of general spaceship construction.

[jrandom]

I'll think about it but I'm not inclined to on the grounds that it falls under the purview of general spaceship construction.

What? No way! It's totally up to the author of the realistic heating mod to tell people to put batteries in their spaceship! BRB, have to go tell ferram to add rover wheel angle modification tweakables to FAR.

[SmarterThanMe]

I'll think about it but I'm not inclined to on the grounds that it falls under the purview of general spaceship construction.

Up to you. But it did take me a while to figure out why my otherwise well constructed reentry vehicle (hell, I had brought the same pod down without any more than the two Z-100's it had a 1000 times in 0.90) was dying, particularly when there was no outward sign of an AoA issue (i.e., didn't obviously flip out before it obliterated itself).

[Olsson]

Does anyone know a good config that works well with SKY - Scaled up Kerbin mod? At the moment all heatshields (including the mk1 command pod with integrated heat shield) blows up instantly on the launch pad.

[Gryphon]

Up to you. But it did take me a while to figure out why my otherwise well constructed reentry vehicle (hell, I had brought the same pod down without any more than the two Z-100's it had a 1000 times in 0.90) was dying, particularly when there was no outward sign of an AoA issue (i.e., didn't obviously flip out before it obliterated itself).

Well, then you've done better than me. I've had PLENTY of fun with running out of power at the worst possible times, so I look for that pretty quick. I've learned to check the resources window a lot, and to keep it locked open if I'm dropping low before a critical maneuver. Oh, and the "Can I get through reentry before I lose power" game is much more interesting if you use Remotetech.

[Starwaster]

You know, all of the shields now have their center of pressure adjusted to be stable blunt end first, so if you orient them to be retrograde at interface then they'll stay that way. Or you can set them gently spinning for additional stability.

[SmarterThanMe]

Well, then you've done better than me. I've had PLENTY of fun with running out of power at the worst possible times, so I look for that pretty quick. I've learned to check the resources window a lot, and to keep it locked open if I'm dropping low before a critical maneuver. Oh, and the "Can I get through reentry before I lose power" game is much more interesting if you use Remotetech.

I do. You can't see my crazy eyes.

[ICirceI]

My ships keep going poof even at extremely shallow reentries. They just poof at around 32k and for some reason they make it to like 24k if the reentry is steep, but they always go poof, even if it just the pod and nothing else.

[Sokar408]

So once again, with 7.1.0 release, I tried DRE again. Now the problems I was experiencing seems to be gone, at least the primary problem of things blowing up for no reason. However there are still the problem of how the shields seem to function aerodynamically. When I make a small craft, 1 pod, 1 small fuel tank, and 1 heat shield (DRE heat shield), and reenter, the whole thing will tend toward bending 35-45 degrees off of retrograde. Needless to say it ends in explosions. When doing the same with a stock heat shield of the same size (1.25 m), everything lines up as it should, and reenters with no problems or explosions. Since the mass of the shields, and the CoM of the craft in both cases are the same, I assumed something was off with the DRE shield itself, and its aerodynamic profile.

So I tested a heat shield reentering on its on, and what it does is amazing. It turns 90 degress, so its going in like a flying saucer. I am using Stock Aero btw, not FAR.

[Gryphon]

My ships keep going poof even at extremely shallow reentries. They just poof at around 32k and for some reason they make it to like 24k if the reentry is steep, but they always go poof, even if it just the pod and nothing else.

In days of yore, shallow reentries were good. Now, they are bad for craft survival. You can find detailed explanations in Starwaster's posts, but a reentry with a low periapsis causes more gee's and a higher max temp. A reentry with a higher periapsis avoids the high gees from deceleration and the high max temp, BUT you gain more heat overall. So, you actually want to dive deeper than before.

I learned my lesson during ascent on an aggressive gravity turn. My ship was pretty much horizontal, at about 55000m altitude, getting close to orbital velocity, when it overheated and blew up.

[Starwaster]

My ships keep going poof even at extremely shallow reentries. They just poof at around 32k and for some reason they make it to like 24k if the reentry is steep, but they always go poof, even if it just the pod and nothing else.

Don't go so shallow. For Kerbin, a periapsis of 20km is pretty good.

So once again, with 7.1.0 release, I tried DRE again. Now the problems I was experiencing seems to be gone, at least the primary problem of things blowing up for no reason. However there are still the problem of how the shields seem to function aerodynamically. When I make a small craft, 1 pod, 1 small fuel tank, and 1 heat shield (DRE heat shield), and reenter, the whole thing will tend toward bending 35-45 degrees off of retrograde. Needless to say it ends in explosions. When doing the same with a stock heat shield of the same size (1.25 m), everything lines up as it should, and reenters with no problems or explosions. Since the mass of the shields, and the CoM of the craft in both cases are the same, I assumed something was off with the DRE shield itself, and its aerodynamic profile.

I don't agree that the behavior of the stock heat shield is aerodynamically realistic.

'everything lines up as it should'

Really? That seems normal to you? Without anything to stabilize it, it will just straighten up on its own?

So I tested a heat shield reentering on its on, and what it does is amazing. It turns 90 degress, so its going in like a flying saucer. I am using Stock Aero btw, not FAR.

It's a flat plate.

By itself (in real life) it wouldn't be particularly stable either flat end on or edge on. It would flutter quite a bit. But especially it wouldn't just present its flat face into a hypersonic airstream and stay stable like that without SOMETHING to keep it stable.

Sorry but I think this is one of those times that I have to bounce that ball back into your court and tell you that it's your responsibility to design your craft in a manner that they will stay stable.

And it's not that hard to do. I tested every one of those shields and they ARE stable if you treat them right and don't make unrealistic demands of them. They're a lot more stable than they were pre-7.1.0

But don't stick them at the bottom of a stack and expect that they're going to magically keep you from flipping. They're thermal protection, not control surfaces or stabilizers. They're meant for the bottom of pods or very SHORT stacks.

In days of yore, shallow reentries were good. Now, they are bad for craft survival. You can find detailed explanations in Starwaster's posts, but a reentry with a low periapsis causes more gee's and a higher max temp. A reentry with a higher periapsis avoids the high gees from deceleration and the high max temp, BUT you gain more heat overall. So, you actually want to dive deeper than before.

I learned my lesson during ascent on an aggressive gravity turn. My ship was pretty much horizontal, at about 55000m altitude, getting close to orbital velocity, when it overheated and blew up.

in a realistically sized planet where we don't have to speed up heating, you could conceivably do things more shallow than stock sized Kerbin forces us to. As I had to remind someone just the other day, with stock Kerbin, our goal is actually unrealistic amounts of heating, or we couldn't have Deadly Reentriesâ„¢.

[Sokar408]

Don't go so shallow. For Kerbin, a periapsis of 20km is pretty good.

I don't agree that the behavior of the stock heat shield is aerodynamically realistic.

'everything lines up as it should'

Really? That seems normal to you? Without anything to stabilize it, it will just straighten up on its own?

It's a flat plate.

By itself (in real life) it wouldn't be particularly stable either flat end on or edge on. It would flutter quite a bit. But especially it wouldn't just present its flat face into a hypersonic airstream and stay stable like that without SOMETHING to keep it stable.

Sorry but I think this is one of those times that I have to bounce that ball back into your court and tell you that it's your responsibility to design your craft in a manner that they will stay stable.

And it's not that hard to do. I tested every one of those shields and they ARE stable if you treat them right and don't make unrealistic demands of them. They're a lot more stable than they were pre-7.1.0

But don't stick them at the bottom of a stack and expect that they're going to magically keep you from flipping. They're thermal protection, not control surfaces or stabilizers. They're meant for the bottom of pods or very SHORT stacks.

in a realistically sized planet where we don't have to speed up heating, you could conceivably do things more shallow than stock sized Kerbin forces us to. As I had to remind someone just the other day, with stock Kerbin, our goal is actually unrealistic amounts of heating, or we couldn't have Deadly Reentriesâ„¢.

So you are telling me, that a command pod, a http://wiki.kerbalspaceprogram.com/wiki/FL-T200_Fuel_Tank, and DRE heat shield, are suppose to flip, on its own, 40-45 degrees on reentry? I'm sorry but that is a short craft, and given that if I try to reenter, even WITHOUT a shield, it goes in just as expected (it doesn't last that long though), it seems more like that in your opinion, the aerodynamics are wrong, which I'm not informed enough to disagree with. However since DRE isn't an aerodynamics mod, it seems very odd that you would either intentionally design the shields in such a way, that they do not behave as they would be expected to, or that you'd keep things this way, merely because you think its more realistic, regardless of rather its in the informed scope of the mod.

Again this is your mod, and I have been loving it to bits, but this seems more like pride then anything else. I'll happily make a video, and show what I mean, and if you still think that my point is invalid, then so be it. But as it stands it just seems mind-buckling to me, that you'd think this is how the parts should behave. Again maybe I'm not describing it accurately enough, or maybe I'm experiencing a bug, or maybe my way of playing is just all together wrong. So if I record it, and show you exactly what I'm doing, would you take a look?

[Kussris]

Hi!

I like the new Deadly Reentry mod! Thanks for making it work with KSP 1.0.

But I need help for adjusting the settings (alt F12). I get the re-entrey effects during launch (I am not to low and to fast) and I like to make it more deadly. Which settings are to be changed?

Thanks for helping me.

[yardpup01]

So I tested a heat shield reentering on its on, and what it does is amazing. It turns 90 degress, so its going in like a flying saucer. I am using Stock Aero btw, not FAR.

Interesting, because I have the exact opposite happen with FAR installed. My heat shields are redicuously stable on their own. I've found that I can't decouple them until my chutes have fully deployed as the terminal velocity of a 1.25m heatsheild seems to be ~7m/s. If I release it too early it destroys my craft as it tries to slow down.

[Starwaster]

So you are telling me, that a command pod, a http://wiki.kerbalspaceprogram.com/wiki/FL-T200_Fuel_Tank, and DRE heat shield, are suppose to flip, on its own, 40-45 degrees on reentry? I'm sorry but that is a short craft, and given that if I try to reenter, even WITHOUT a shield, it goes in just as expected (it doesn't last that long though), it seems more like that in your opinion, the aerodynamics are wrong, which I'm not informed enough to disagree with. However since DRE isn't an aerodynamics mod, it seems very odd that you would either intentionally design the shields in such a way, that they do not behave as they would be expected to, or that you'd keep things this way, merely because you think its more realistic, regardless of rather its in the informed scope of the mod.

Again this is your mod, and I have been loving it to bits, but this seems more like pride then anything else. I'll happily make a video, and show what I mean, and if you still think that my point is invalid, then so be it. But as it stands it just seems mind-buckling to me, that you'd think this is how the parts should behave. Again maybe I'm not describing it accurately enough, or maybe I'm experiencing a bug, or maybe my way of playing is just all together wrong. So if I record it, and show you exactly what I'm doing, would you take a look?

You accuse me of pride? That's rather insulting.

I don't think your video will be necessary. Your description was fairly explicit.

Let's look at some pictures.

A command pod - a Mk1 based on your description (all 1.25m parts) (a chute on top)

A T200 tank

A 1.25m shield

Is this about right? Look at the center of mass. Pretty much dead center of the stack. The entire thing is free to pivot around that point.

Look at it in flight. The flight camera focuses on the center of mass. And sure enough, it's pivoting freely around that point; flopping around it basically. Does that look like anything you've ever seen landed on another planet IRL? If its center of mass were further down it would have a chance. A wider heat shield would be helpful too. (in fact IRL it really needs to be broader on the bottom or that tank better protected because it would burn otherwise)

So, again: I don't feel that it is realistic to expect that this thing should be stable in reentry. Pride has nothing to do with it.

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Hi!

I like the new Deadly Reentry mod! Thanks for making it work with KSP 1.0.

But I need help for adjusting the settings (alt F12). I get the re-entrey effects during launch (I am not to low and to fast) and I like to make it more deadly. Which settings are to be changed?

Thanks for helping me.

If you increase convection factor that will serve to increase the rate of heating. I like to adjust radiation factor to match; it makes spaceplanes more viable. You can also adjust aero heating production, which I was doing for awhile but it makes things too hot in subsonic. You can also go into the stock difficulty settings and increase reentry heat there by up to 120% and that does affect Deadly Reentry. (mach only)

[diomedea]

...

So, again: I don't feel that it is realistic to expect that this thing should be stable in reentry. ...

There are reasons why ships stay upright under the effect of external forces even while their center of mass would seem to make them turn. The center of pressure where the drag force is applied moves with the angle the ship has. If the shape of the hull is such to present an appropriately curved bottom to the flow, the center of pressure moves away from the line where the flow encounters the center of mass, and that results in a stabilizing effect.

The subject is the same that is studied with naval statical stability, where the movement of the center of buoyancy describes an arc with roll, and stability is given by the metacentric height (distance of the center of that arc, "metacentre", from the center of mass). With ships, the buoyancy is greater on the side the ship is rolled, and that has a greater effect than momentum from weight. With a pod in a aerodynamic flow, drag is greater on the side of the roll as well, and as well returns the pod to a stable position.

[Starwaster]

There are reasons why ships stay upright under the effect of external forces even while their center of mass would seem to make them turn. The center of pressure where the drag force is applied moves with the angle the ship has. If the shape of the hull is such to present an appropriately curved bottom to the flow, the center of pressure moves away from the line where the flow encounters the center of mass, and that results in a stabilizing effect.

The subject is the same that is studied with naval statical stability, where the movement of the center of buoyancy describes an arc with roll, and stability is given by the metacentric height (distance of the center of that arc, "metacentre", from the center of mass). With ships, the buoyancy is greater on the side the ship is rolled, and that has a greater effect than momentum from weight. With a pod in a aerodynamic flow, drag is greater on the side of the roll as well, and as well returns the pod to a stable position.

Thats nice general information, thank you, but it doesn't change anything.

[diomedea]

Thats nice general information, thank you, but it doesn't change anything.

Well, it should make considerations change the moment is clear the shape of the reentry pods have never been flat ones, but rather profiled (most commonly spherical sections at the bottom, where drag has effect). And the reason being the one I showed above.