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

[Starwaster]

Can the G-force damage be configurable/disable-able in the next version?

I've currently got a local copy with it disabled, but it is a mite tedious to have to recompile the code every time a new version comes out. Configuration files exist for a reason.

Is anyone working on a next version?

[BubbaWilkins]

As a foreword, I do not disagree with the concept of acceleration damage. What I disagree with is DRE's implementation.

I've gotten a little tired of arguing that DRE's g-force damage is bogus and people trying to use Newton's three laws to prove that the g-force damage is not bogus, so I did up a diagram (by hand and scanned in. strokes inconsistent because I use a fude-pen).

It's not that g-force damage is bogus, but that it's a reasonable approximation for sub-component failure beyond the actual stresses being calculated by at the connection nodes. I think a lot of people are blaming it for structural failures which would occur even if DRE was not installed.

If you see "Mechjeb 2 exceeded G-force tolerence, thats a DRE thing.

If you see "Structural failure..etc etc etc..." That's a KSP thing

The latter would occur if you didn't have DRE installed.

[Zeroignite]

The problem is that the internal g-force damage threshold is way too low. If I want to do a 60m/s² launch (not really unreasonable compared to real-world unmanned launches), I should worry about parts breaking apart from each other, but having things like antennas implode in on themself is kind of silly.

[The Lone Wolfling]

It's not that g-force damage is bogus, but that it's a reasonable approximation for sub-component failure beyond the actual stresses being calculated by at the connection nodes. I think a lot of people are blaming it for structural failures which would occur even if DRE was not installed.

If you see "Mechjeb 2 exceeded G-force tolerence, thats a DRE thing.

If you see "Structural failure..etc etc etc..." That's a KSP thing

The latter would occur if you didn't have DRE installed.

I, for one, am aware of the distinction.

That being said, I don't particularly see why the g-force damage exists in the first place. For example: the Sprint missile accelerated at 100G. 100G! G-force alone isn't an issue, ever - the issue is the actual amount of stress, and that's already covered by structural failure. If applying 1MN of force to a full fuel tank doesn't break it, than applying 1MN of force to the fuel tank when it's empty shouldn't break it either. There are some exceptions, as always, but that's true in general. Structural failure should be all that's necessary, at least for unmanned crafts. I personally would like it if a plugin started restricting controls at higher accelerations if you had kerbals on board and no probe body, but straight G-force damage just makes things annoying without adding value to the mod, or at least that's what I've found.

Is anyone working on a next version?

I don't know. And I cannot find the license anywhere (don't addons require a license displayed?), so I cannot even know if there's any point in doing anything myself - I've already got a nerfed version myself, and would happily make a patch to add a configuration option for G-force damage, but don't see the point unless I know I can release it.

[taniwha]

BubbaWilkins: My complaints are very specifically about DRE. Whenever something happens, I check the report to work out why (eg, where to add a strut). Considering it was things like the fuel tank or engine itself imploding under acceleration, there is no way I'd accept that "internal damage" argument. Pipes and such are very light compared to their strength. A nose cone collapsing at 6g? Not likely. They're too simple, too light, and too strong (they have to withstand aerodynamic forces).

As I've said before: it's not the concept, it's the implementation. Having a per-part maximum acceleration (for internal damage) is fine, but it will be independent of the impact tolerance (think of glass: low impact tolerance, but it is very strong and thus can sustain large loads (thus high acceleration)). External damage needs to take into account not only the parts strength, but the masses externally connected to the part and thus the external forces on the part.

[NathanKell]

The Lone Wolfling, IIRC ialdabaoth's works are CC-sharealike.

Ah, here we go: http://forum.kerbalspaceprogram.com/showthread.php/31706-0-20-Modular-Fuel-System-1-3-realistic-fuels-reconfigurable-fuel-tanks-and-engines?p=462889&viewfull=1#post462889

Edited September 8, 2013 by NathanKell
Found link

[The Lone Wolfling]

The Lone Wolfling, IIRC ialdabaoth's works are CC-sharealike.

Ah, here we go: http://forum.kerbalspaceprogram.com/showthread.php/31706-0-20-Modular-Fuel-System-1-3-realistic-fuels-reconfigurable-fuel-tanks-and-engines?p=462889&viewfull=1#post462889

Good to know.

In that case, here is a modified version of DR that doesn't have the G-force damage. Install DR as usual, drop this DeadlyReentry.dll over the copy in the stock install, and you should be good to go. Source is DR 2.3 with line 219 removed ("CheckGeeForces();"). ialdabaoth is awesome. This is also released under CC-sharealike. If this copy gets enough downloads, I'll look at adding a configuration for it. That is all.

[NathanKell]

I'd dearly love config. When I had time, I was going to change it so it loaded all its constants (used in the G-force tolerance calculation) from the DRE confignode.

...haven't had time yet, obviously.

I refuse to play without any G-force damage (some aerobrakes just shouldn't be survivable) so I'll stay with current for now, but even what you've just posted will be awesome for so many people!

[BubbaWilkins]

Guess it's just me then. I kind of like the challenge of keeping stresses below the redline.

[taniwha]

BubbaWilkins: I have no problem with having a redline, or even that it's usually kind of low*. It's the bogosity of of being able to sandwich something small between a mainsail running at full throttle and a full jumbo-64, yet the same something can't withstand the mainsail with nothing but a tiny probe body above it. That is, if a part breaks under high acceleration, it should break under lower acceleration while pushing on a large mass.

* The current fix for a low redline (increase the impact tolerance) is terrible. To get parts that can survive reasonable acceleration (up to about 15g), you wind up with parts that merely bounce off the ground.

[NathanKell]

Not just you. At _most_ I'd double G-limits; it's just weird that my planes break at 7G when they ought to be stressed for at least nine. (or >6G accel when tanks are almost dry...can't remake the Scout for this reason). But like I said, I do want about 80% of the current G challenge.

[taniwha]

when I've got some time and energy, I want to take a look at doing g-force damage... better. I doubt "right" will be possible.

[Zeroignite]

hm, any idea why stock parts that should be getting AblativeShield aren't? I checked the installation, and it looks correct.

[The Lone Wolfling]

hm, any idea why stock parts that should be getting AblativeShield aren't? I checked the installation, and it looks correct.

Is ModuleManager properly installed? Is the MM config file missing?

[Zeroignite]

Is ModuleManager properly installed? Is the MM config file missing?

Ah, there is it. Having modulemanager.dll directly under GameData in the release download threw me off and I missed it. Thanks!

[Splode]

I try this mod out every so often, but every time I do, it still seems overly harsh and not particularly compatible with an otherwise vanilla installation of KSP. Oh well, keep up the good work, you're getting there!

[jrandom]

I've been running DE since a week after first installing KSP and don't find it overly harsh -- on the flipside, maybe most KSP'ers fly overly-aggressively? I installed DE after a return-pod survived what should have been certain doom and explodey badness and I realized my kerbals didn't actually have much in the way of peril once I had the basics figured out. DE makes me pay very careful attention to my rocket design and flight profiles, but I haven't encountered anything that made my say, "hey! they should have survived that!".

In a 1/10th-scale solar system with fairly cartoonish-simplistic physics, DE's current settings seem fitting. Maybe a bit of tweaking to the values, but I don't think anything major is needed (past adding differentiating between acceleration and compression forces as have been mentioned here and in other threads).

Edited September 12, 2013 by jrandom

[dlrk]

I also don't find DE overly harsh. The best way to understand it is the lower your periapsis before hitting the atmosphere, the steeper the descent. The steeper descent, the higher the heat. So, a successful reentry requires a periapsis in the 20-40 range. Experiment there, and find what you like and what works for your spacecraft.

[NathanKell]

DE is...kinda ridiculously easy, actually. I almost never use my whole heatshield. Only time I can remember (recently) burning up is finishing a gravity turn too early (1800m/s at 30km) and having some science parts burn up.

Bad for sounding rockets (going down) and SRBs (going up) because of G-limits, but for normal reentries? Easy stuff.

[InfinityArch]

Deadly Reentry makes Eve missions of any sort hellishly difficult. Which is a good thing IMHO.

Of course, it makes drogue chutes an absolute requirement for reliable unpowered descent in non-spaceplane designs if you're using it alongside FAR, and I can't seem to find a decent looking radial or interstage drogue chute.

Also, I've notied when using this mod in 0.21, spacecraft in Kerbin's atmosphere tend to explode or loose parts with low heat tolerance when loading quicksaves. Not sure why that is, but I'd really like it if someone could fix that bug.

[jrandom]

Of course, it makes drogue chutes an absolute requirement for reliable unpowered descent in non-spaceplane designs if you're using it alongside FAR, and I can't seem to find a decent looking radial or interstage drogue chute.

The FASA Mercury/Gemini pack comes with radial drogue chutes. I just got this pack and so haven't tried them out yet. (I've got both DE and FAR running, so your questions is also pertinent to my interests.)

[NathanKell]

Nope, it doesn't. Just be sure to deploy your chute once you go subsonic (and the supersonic/transonic shockwave decreases).

[taniwha]

Also, I've notied when using this mod in 0.21, spacecraft in Kerbin's atmosphere tend to explode or loose parts with low heat tolerance when loading quicksaves. Not sure why that is, but I'd really like it if someone could fix that bug.

I think I know what's going on here. I suspect DRE is not waiting for physics to be enabled before doing its various checks. Worse, it seems DRE might not be checking which scene is loaded and thus the burning sounds when placing the nosecones in the VAB (SPH too?)

[BigNose]

Deadly Reentry makes Eve missions of any sort hellishly difficult. Which is a good thing IMHO.

Of course, it makes drogue chutes an absolute requirement for reliable unpowered descent in non-spaceplane designs if you're using it alongside FAR, and I can't seem to find a decent looking radial or interstage drogue chute.

[...]

Have you tried this Radial Drogue Parachute by Konraden?

[SeventhArchitect]

I'll check this out, cause it's legit. It seems that every time I take on reentry, absolutely nothing happens even when my entire ship is surrounded in molten air (lol, wtf, thats called plasma).

I'd be traveling so fast in a jet, or I'd be taking on reentry, and not once have I seen a single weak component, like maybe a single solar panel, fly off.

This will also make things interesting.