Flight Heat effects applied differently before and after save+load [save made after decoupling event]

[hatterson]

Reported Version: v0.2.0 (latest) | Mods: none | Can replicate without mods? Yes 
OS: Win 11 | CPU: Ryzen 9 5900HS | GPU: RTX 3070 Laptop version | RAM: 16GB

 

Severity: Medium

Frequency: High in the sense I can reproduce it reliable. Low in the sense that it's not a super common situation.

 

After a bunch of testing I *think* this is actually related to the inflatable heat shield (which already has issues) but I'm submitting this since in case investigation leads to more.

I noticed that with a very specific craft build heating effects would get applied differently (harsher) after saving and loading the game. Specifically a craft would fully survive re-entry if I didn't save+load, but after saving + loading it would not survive subsequent attempts.

After repeated testing and playing around the only way I was able to get it to occur was if the inflatable heat shield was used and the save was made after the decoupler under it fired.

Full reproduction steps:

1. Create a craft that's a Mk3-L wanderer, inflatable heat shield, medium decoupler, medium lox tank, and poodle engine. Attached a picture of it with the fairing off on the heat shield so you can see it to confirm.
2. Launch it and use alt+f8 to get it into a minimum Kerbin orbit. 87500ap/pe
3. Make a named save (e.g. 'before burn') but don't load it.
4. Burn retrograde to get PE to ~57km.
5. Make another named save (e.g. 'before decouple') but don't load it.
6. Decouple. PE should be ~55km
7. Make a third named save (e.g. 'after decouple')
8. Point orbital retrograde but do not inflate the heat shield, just let it truck into the atmosphere. it should make it all the way through the atmo. Consistently I saw it start visual effects around 35-37k, and the heat bar at 25k that went away at 15-20k. Craft will eventually crash into Kerbin (RIP Kerbals)
9. Load 'after decouple' save and let craft follow identical path into atmosphere. It should consistently show a heating bar in the mid 60ks and blow up in the 60-61k range.
10. You can load 'before burn' and 'before decouple' saves and continue steps from there to see the craft behave as initially and make it through atmosphere without blowing up.

 

As mentioned I played around with a number of different combos. The specific pod didn't seem to matter to the behavior changing, but specific behavior was different with each pod (heat points, etc.) and the specific decoupler used had similar results, although a decoupler had to be present to cause the issue. When I tried with ablative heat shields it appeared that they ablated the same amount in both scenarios although I also didn't do 100% testing on this so may be wrong which is another thing leading me to believe there's potentially a weird interaction between the inflatable heatshield and the decoupler that does away when a save is loaded after the decoupling has taken place.

 

Included Attachments:

Edited January 6, 2024 by DibzNr

[jclovis3]

The inflatable heat shield exploding has got to be a bug. It is supposed to withstand heat better than any other part, and yet much of the ship seems to pull through far better than these hydrogen filled balloons.