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

[sp1989]

Is it possible DRE is affecting the EVA RCS jetpack effects? My kerbals on eva their jetpacks don't have thruster effects. I started uninstalling a reinstalling mods and when I uninstalled DRE the thruster effects came back. For good measure I reinstalled DRE and they went away. I can't see why DRE would do this but it seems to be the culprit of a glitch I have been looking for, for days now. I just never thought it would be DRE but its seems to definitely be the problem. Now it doesn't bother me so I will play through it but I just wanted to know what was causing the problem.

[Namolis]

I couldn't be bothered to respond, sorry.

(but you might try reading the OP, though, it covers this.)

You just did

Sorry, derped a little there. I just read the part where it said "don't change anything" and not the FAQ.

[Starwaster]

But Earth and Kerbin have different scale heights with the same surface pressure. To get the same air density as at 25km altitude at Kerbin, SR-71 would have to fly as high as... 42km at Earth, I guess?

Fair point, but all that really means is that you'll see different specific values. You're still going to (or should be) seeing high altitude heating.

Speed and density? Sounds like dynamic pressure to me. I guess I'll have to look into the code.

shockwave = speed - CTOK; // shockwave temperature is equal to velocity in meters per second converted from Kelvin to Celsius
...
bool cut = Math.Pow(density, ReentryPhysics.densityExponent) * shockwave * 10f
                        > part.maxTemp * ReentryPhysics.parachuteTempMult;

dynamic pressure (pascals) = one half of atmospheric density (kg/m3) times velocity squared

So, no, not really dynamic pressure.

Sorry for stupid questions. I think I understand less and less as I try to relearn how to fly with DRE.

Well that's why the chute failure messages. So people don't have to worry about trying to figure out whether it's safe or not to deploy.

[NathanKell]

Namolis: No probs. And yeah, I can never quite follow through on an attempted unhelpful response.

[Starwaster]

Namolis: No probs. And yeah, I can never quite follow through on an attempted unhelpful response.

Try harder! You have to work at these things

[Starwaster]

Ok, new beta release:

still keeping beta designation; it took several weeks to bring certain inter-mod issues to light so I don't want to do an official release right now.

The highlights of this release are primarily inter-mod issues fixed (hopefully) namely KAS and AJE. And possibly others. (never underestimate the power of the Null Reference error to frack your day up for you)

Another issue that I hope is fixed is aerodynamic FX flickering reported by a handful of people. Hard to say if it's really fixed given the small number of people affected, and if my understanding of the problem was actually correct then it SHOULD have affected more and it just hasn't. Unless larger numbers of people were affected but just didn't bother offering feedback. So, here it is:

Deadly Reentry 6.3.2 (beta)

- Heat shield added to all KW Rocketry fairings

- Deployment speeds for Real Chutes changed to RC legal values. Drag changes removed

- First pass on maxTemp in DeadlyReentry.cfg. Heat shield added to nose cones lacking it.

- conductivity added to shield configs needing it. (including SDHI shield)

- Change heat shield conductivity default to match Part heatConductivity defaults (AJE workaround)

- Error trapping for errors that were breaking KAS (and other mods potentially)

- Allow engines to double ridiculousMaxTemp value

- Exempted engine overheating from affecting Kerbals.

- Added fix (hopefully) for edge cases involving flickering AerodynamicsFX

- Check for DRE scenario null ref.

- Merged NathanKell changes for tech requirements and adding shield to airplane tail and all procedural fairings

- Merged NathanKell FAR detection / OnStart() changes. (moved to Start())

- Kerbal reaction tweaking

[sp1989]

Ok, new beta release:

still keeping beta designation; it took several weeks to bring certain inter-mod issues to light so I don't want to do an official release right now.

The highlights of this release are primarily inter-mod issues fixed (hopefully) namely KAS and AJE. And possibly others. (never underestimate the power of the Null Reference error to frack your day up for you)

Another issue that I hope is fixed is aerodynamic FX flickering reported by a handful of people. Hard to say if it's really fixed given the small number of people affected, and if my understanding of the problem was actually correct then it SHOULD have affected more and it just hasn't. Unless larger numbers of people were affected but just didn't bother offering feedback. So, here it is:

Deadly Reentry 6.3.2 (beta)

Ok Im sorry if this is spam but I posted this before and it might have gotten missed.

"Is it possible DRE is affecting the EVA RCS jetpack effects? My kerbals on eva their jetpacks don't have thruster effects. I started uninstalling a reinstalling mods and when I uninstalled DRE the thruster effects came back. For good measure I reinstalled DRE and they went away. I can't see why DRE would do this but it seems to be the culprit of a glitch I have been looking for, for days now. I just never thought it would be DRE but its seems to definitely be the problem. Now it doesn't bother me so I will play through it but I just wanted to know what was causing the problem."

[Starwaster]

Ok Im sorry if this is spam but I posted this before and it might have gotten missed.

"Is it possible DRE is affecting the EVA RCS jetpack effects? My kerbals on eva their jetpacks don't have thruster effects. I started uninstalling a reinstalling mods and when I uninstalled DRE the thruster effects came back. For good measure I reinstalled DRE and they went away. I can't see why DRE would do this but it seems to be the culprit of a glitch I have been looking for, for days now. I just never thought it would be DRE but its seems to definitely be the problem. Now it doesn't bother me so I will play through it but I just wanted to know what was causing the problem."

Actually I did see that and was intending to answer it but was trying to compose replies to other posts and get the beta release packaged.

There's nothing in the mod that should affect EVA RCS, but errors occurring at just the wrong time can cause any number of problems. The beta traps several such errors that were occurring when one of its modules initialized. (which happens any time a part spawns including Kerbals going on EVA and was causing problems for KAS)

So I'd try the beta and see if that fixes it for you.

[NathanKell]

FYI, I sent a pull request to camlost regarding engine max temps and heat production.

[Jarin]

Another issue that I hope is fixed is aerodynamic FX flickering reported by a handful of people. Hard to say if it's really fixed given the small number of people affected, and if my understanding of the problem was actually correct then it SHOULD have affected more and it just hasn't. Unless larger numbers of people were affected but just didn't bother offering feedback.

Yeah, that's totally been happening to me. It just didn't bother me enough to track down what was causing it. I suspect that's the case for a lot of people. Will see if the update fixes it.

[J.Random]

velocity in meters per second converted from Kelvin to Celsius

At this point, you lost me entirely. *walks away mumbling and waving hands, supposedly in the grc.nasa.gov general direction

[NathanKell]

Heat applied to your craft when flying through an atmosphere depends on two things:

1. The shockwave temperature (how hot the air is).

2. Air density (how much air is hitting you).

In an earthlike atmospher, the temperature of the shockwave (in Kelvin) is roughly equivalent to your velocity in meters per second. Since KSP treats all temperatures as Celsius, we subtract 273.15 from your velocity to get shockwave temperature in C.

[Starwaster]

Yeah, that's totally been happening to me. It just didn't bother me enough to track down what was causing it. I suspect that's the case for a lot of people. Will see if the update fixes it.

Right now it's looking like it broke something else... will have to reexamine this.

[J.Random]

In an earthlike atmospher, the temperature of the shockwave (in Kelvin) is roughly equivalent to your velocity in meters per second.

It doesn't itself depend on air density or reflection angle?

[Starwaster]

It doesn't itself depend on air density or reflection angle?

Not for determining the temperature of the shockwave, no. You do care about density when determining how much heat you're getting from the shockwave.

Think about it like this: What's going to hurt you more this Thanksgiving, reaching into a 200 degree oven to get the turkey out or accidentally spilling water on your hand at 100 degrees? (Celsius)

As far as reflection angle goes I'll only speak to its role in the mod: It controls how much heat your shield is reflecting and in how much your shield is ablating each second.

(and that is almost certainly wrong because ablation rate should be constant with part temperature and not dependent on orientation or density, but changing it now would mean breaking all existing shields)

[Starwaster]

Ok, the fix I did for the AerodynamicFX broke part of it.

Here's a replacement dll. Just drop it into the DeadlyReentry/Plugins/ folder and let it overwrite the existing file. I'll push a replacement update to the download page later

(you especially want this if you play Real Solar System with a smaller FX Density Exponent or you only get flames at the old default altitude)

https://www.dropbox.com/s/moge45bumutdcwj/DeadlyReentry.dll?dl=1

[J.Random]

6.3.2 is much better. Especially the rollback of drag changes: craft seems to slow down much easier in lower atmosphere.

Another mechanics question: what exactly is "shockwave temperature"? The more I read on the subject, the more it seems that shockwave front is not a physical object, more of a pure mathematical (geometrical, whatever) imaginary surface. There's "upstream" - air in front of the shockwave - and "downstream" - air behind the shockwave. Shockwave itself is just a delimiter between this two areas, isn't it? The only sensible heating equation I've found (yet) is a stagnation temperature, which is a maximum temperature achieved on trailing edges, where air flow stops, transfering all its kinetic energy to the craft, and it has no speed in it, just mach number.

[RuBisCO]

I'm having trouble with deadly reentry on 10X Kerbin, none of the heat shields work, simple de-orbit from 250 km to 60 km is death.

[Starman4308]

I'm having trouble with deadly reentry on 10X Kerbin, none of the heat shields work, simple de-orbit from 250 km to 60 km is death.

Please read the first post. The issue is that Deadly Reentry is calibrated to stock, where a Munar reentry is a paltry 3 km/s.

[Starwaster]

6.3.2 is much better. Especially the rollback of drag changes: craft seems to slow down much easier in lower atmosphere.

Another mechanics question: what exactly is "shockwave temperature"? The more I read on the subject, the more it seems that shockwave front is not a physical object, more of a pure mathematical (geometrical, whatever) imaginary surface. There's "upstream" - air in front of the shockwave - and "downstream" - air behind the shockwave. Shockwave itself is just a delimiter between this two areas, isn't it? The only sensible heating equation I've found (yet) is a stagnation temperature, which is a maximum temperature achieved on trailing edges, where air flow stops, transfering all its kinetic energy to the craft, and it has no speed in it, just mach number.

It's not imaginary. As an object passes through the air at supersonic or hypersonic speeds, the air bunches up in front of it. Compression of any material raises the temperature. As said before, the resulting temperature increase in Kelvin is roughly equal to the object's velocity in meters per second. That's temperature. Think of temperature as the average amount of heat. Temperature is not quantity. Heat is quantity. Dense materials or media have more heat than less dense materials. So high up in the atmosphere at 7000 meters per second, the temperature is about equal to 7000 K. The denser the air, the more heat is transferred to the reentry vehicle.

Blunt bodied objects like the backside of an Apollo capsule work to keep most of the shockwave from contacting the hull and also provide a lot of drag to slow the craft down. However, I've also seen it said that pointier vehicles would be better because most of the shockwave would pass by harmlessly. Maybe that's true too, but they don't provide enough drag to slow down an incoming capsule full of astronauts.

I'm having trouble with deadly reentry on 10X Kerbin, none of the heat shields work, simple de-orbit from 250 km to 60 km is death.

There's a FAQ on the very first page that answers questions like this. It has a link to a file that provides shields designed for planets on that scale. (though I need to create a version of it that is not RO specific, it will work for you)

That said, you might want to try the beta. Default DRE shields might deplete faster but will still protect better in the beta. They may deplete faster but will resist heating better. That part is still WIP, but when I test the beta with 10x Kerbol, I I explicitly do so without the RSS / RO class shields because one of the goals of the beta is to not be reliant on special configs. The logic is that materials that evaporate or sublimate do not heat up past the temperature of evaporation / sublimation until there is no more ablator left. (The same principle makes it possible to boil water in a paper cup: Paper can not reach its ignition point because it will not heat up past the boiling point of water unless massive amounts of heat are concentrated on it)

Another word of advice, the more time you spend in the upper atmosphere, the more time you have to slow down. Some people might tell you to adopt a steeper reentry angle but that can result in high G forces killing your Kerbals.

[RuBisCO]

Well may problem is a little more odd then that, I can get the Mk1 pod back from 250X60 km orbit, as long as I don't using physics warp, with 115 out of 250 ablative cork left. If I use physics warp it blows up at 60 km going ~6500 m/s.

Also things go crazy if I activate debug mode (Alt+D+R), phantom forces, gee force off the chart, crazy kraken attack.

If I don't physics warp and don't activate the debug menu, all is well except a specific part, my Jeb 9000 burns up and heats up as if it is unshielded, not other parts like parachute or side decoupler which heat up as if they are shielded despite the mechjeb part being between them.

Edited November 28, 2014 by RuBisCO

[Starwaster]

Well may problem is a little more odd then that, I can get the Mk1 pod back from 250X60 km orbit, as long as I don't using physics warp, with 115 out of 250 ablative cork left. If I use physics warp it blows up at 60 km going ~6500 m/s.

Also things go crazy if I activate debug mode (Alt+D+R), phantom forces, gee force off the chart, crazy kraken attack.

A specific part, my Jeb 9000 burns up and heats up as if it is unshielded, not other parts like parachute or side decoupler which heat up as if they are shielded despite the mechjeb part being between them.

Then don't use physics warp. I can't compensate for that in the code, especially when floats are mixed with doubles. Don't do it. Edit: A better explanation. When you speed up time like that, I'm dependent on the game telling me how much time passes between updates so that the code knows how much material needs to ablate from your shield and how much heat to apply to the parts. Fast forwarding results in lower precision. It leads to more math errors.

Your 'phantom forces' are the result of accidentally enabling trim. That's what alt+D does. You can cancel trim with alr+x or use the beta which has a toolbar activated menu from which you can access debug settings. Settings are specific to each of the three difficulty settings.

Give me the part name of the jeb 9000 from its part config file and I'll try to tweak some settings for it in the next DRE release.

Edited November 28, 2014 by Starwaster

[RuBisCO]

Part name is "Dishy_Jeb.9000" there is also "Dishy_Bill.9000"

--- Beta is a lot nicer, thanks.

Edited November 28, 2014 by RuBisCO

[Starwaster]

Part name is "Dishy_Jeb.9000" there is also "Dishy_Bill.9000"

--- Beta is a lot nicer, thanks.

Try replacing your DeadlyReentry.cfg file with this version: https://www.dropbox.com/s/dzyccxas59z2d7l/DeadlyReentry.cfg?dl=1

It adds entries that try to increase detection for shielding for those parts

[RuBisCO]

Yeah that seemed to fix it.