Parts & Vessels Inflatable Heatshield Does Not Correctly Resist Heat

[KerbalabreK]

Reported Version: v0.2.0 (latest) | Mods: none | Can replicate without mods? Yes 
OS: Windows 11 Professional | CPU: i7-13620H | GPU: Nvidia RTX 4060 Laptop | RAM: 32GB

 

When extended, the HS-I 10m heatshield can't withstand any heat, just like any other components and instantly blow up when entering eve's atmosphere. As far as what I've seen, the status of the heatshield displayed in the Part Manager shows "moving" even after the heatshield is fully extended. I guess that it's due to the forgotten code to set the heatshield's status to "extended" thus it continues to use the heat-tolerance config of its retracted or moving state.

One more question is that is this supposed to be retractable? And to mention that the status stays being "moving" even after retracted.

How to reproduce: Just try entering eve's atmosphere with HS-I heatshield

Screenshot - The status remains "moving" even after fully extended.

 

Edited December 25, 2023 by The Space Peacock

[hatterson]

More Detailed Information

Adding some testing I've done while looking at the JSON.

To ensure nothing else silly was going on I created a brand new sandbox save. I then made a simple craft. A pod with a giant truss out the top and a square connector on top of that. On each side of the square connector I placed an HS-I Deluxe inflatable heat shield ("heatshield_v2_inflatable"). I did this manually each time without using symmetry so that I could control each one individually.

• With the one attached to the "front" node of the square connector I clicked the extend button in the VAB one time to have it extended. The status in the VAB read "moving" despite being open.
• With the one attached to the "left" node of the square connector I clicked the extend button in the VAB twice to extend it and then retract it. The status in the VAB still read "moving" even after being fully closed.
• I left the other two alone.

I launched the flight and made a save to check the json

• The heatshield attached to the "front" node listed it's in game status as "Moving" and the status in the json was "Retracting" (PartModulesState.ModuleData.DataObject.CurrentDeployState.storedValue)
• The heatshield attached to the "left" node listed it's in game status as "Extended" and the status in the json was "Retracting"
• Both the heatshields attached to the "back" and "right" nodes stated their in game status as "" and the json status was "Retracted"

I then manually inflated the part attached to the "back" node and waited roughly 30 seconds after the animation was finished to ensure it had fully done it's thing. I then did a save again to confirm the json:

• Unsurprisingly the heatshields on the front, left and right nodes remained unchanged.
• The heatshield attached to the "back" node listed its in game status as "Moving" and the json status was "Extending"

 

I then wanted to test the heat shield itself so I made a new craft. An Mk3-L "Wanderer" pod, the HS-I Deluxe inflatable heat shield below it, a TD-25 decoupler below the heat shield, an X200-16 fuel tank and an RE-L10 "Poodle" engine. I launched and then teleported into the minimum Kerbin orbit, 86,750x86750. I burned retrograde to lower my PE until my orbit was reentering Kerbin then staged leaving me with final orbit values of AP 86,741 and PE 56,691, a very shallow reentry.

I made a save here and checked the json. As expected the heatshield had its deployment state as "Retracted"

I then went in game and, without deploying the heat shield, warped to atmospheric re-entry. I set SAS on surface retrograde and let it go hands off. On the way down I received a heat bar for a short time between roughly 35000m and 20000m on the heat shield, but eventually slowed to a couple hundred m/s (no parachute so would have crashed, but that's not the point) prior to it even reaching the flashing point, much less exploding. I then reloaded the save I had and repeated this undeployed re-entry 2 additional times. On each of those times however my command pod had a heat warning starting at roughly 66000m and it exploded at roughly 61000m. (Edit to note: The differing behaviors between is documented here: 

I then did 3 tests where I deployed the heat shield prior to atmospheric entry. The status of the heat shield in game remained "Moving" with the json status at "" In all three of these tests the heatshield gave a temperature warning at roughly 64,500m and exploded at roughly 60-61,000m

Additionally I noticed that the "Heat Shield Extended" toggle was marked off in game and clicking the button would do nothing leaving my unable to retract it NOTE: This is related to this bug report

 

For my third test I modified the json on the part so that the deploy state of the heatshield was set at "Extended" and marked "IsExtended" to true and "IsExtending" to false. These values match how deployable legs change in the json, so I assume they're correct although without a functioning inflatable heat shield I obviously can't confirm if there's not some other setting still off.

Once doing this the issue above where the "Heat Shield Extended" toggle being marked as false was resolved. However, unfortunately despite the heat shield actually being marked as "extended" it still exploded with the same parameters as above.

Conclusions

• There is a bug with the inflatable heat shield that causes the deployment status to not fully switch. This causes issues with it remaining "moving" in game and desyncing the toggle button with the state of the heat shield at times
• Even if you manually correct this in the json and mark it as extended, the heat shield still blows up on even extremely shallow Kerbin re-entries and ends up exploding at similar positions when deployed or extended and similar positions to a raw pod as if it doesn't actually have any heat resistance. These are re-entries that ablative heat shields survive with absolutely zero issues.

Edited January 7 by hatterson

[ww1612]

Reported Version: v0.2.0 (latest) | Mods: none | Can replicate without mods? Yes 
OS: Win11 | CPU: 12900 | GPU: 4080 | RAM: 32

 

Unlike the normal heat shield, which burns ablator, the inflatable heat shield would simpily reach the maximum temperature and  explode.

It makes the inflatable heat shield useless for reentry of heavy vessels.

 

is it a bug?

Or is it the feature? (only for light vessels, which decelerate quickly by air drag)  

 

 

Included Attachments:

Edited December 24, 2023 by Spicat

[The Space Peacock]

the heatshield blowing up at Eve might be the result of a another bug that causes too much heating in upper atmospheres. pretty sure it's indeed supposed to be retractable

[KerbalabreK]

13 hours ago, The Space Peacock said:

the heatshield blowing up at Eve might be the result of a another bug that causes too much heating in upper atmospheres. pretty sure it's indeed supposed to be retractable

That might be one of the factors. However, other types of heatshield with ablator work, and I suggest that the part status that's forgotten to be changed is the main cause of this bug.

[The Space Peacock]

@ww1612 merged your report

 

[MARL_Mk1]

I can confirm this bug. Cannot get an inflatable shield to go through Duna atmosphere the same way a regular heat shield does.

At the moment feels like the inflatable shield behaves like any other normal parts do when it comes to heat

Edited December 25, 2023 by MARL_Mk1

[WingC3]

Yeah, I tried it on a very shallow Kerbin entry and it didn't survive. The engines on the lander handled the heat better just being exposed. Really looking for this to be fixed as I have an awesome Laythe lander that would be GREAT with it, but won't make it without it.

[FlyingBobino]

Happened to me as well - not sure if it's related to defined "heat resistance" values or due to its stage - even after opening the heat shield fully it still registers its stage as "moving" in the parts UI

[Jose Tortola]

Reported Version: v0.2.1 (latest) | Mods: none | Can replicate without mods? Yes 
OS: Windows 11 | CPU: Ryzen 9 5900X | GPU: NVIDIA RTX 3090 | RAM: 32Gb

Title: As the post's title hints, thermal shield HS-I does not shields against thermals on reentry.

Severity: med.

Frequency: high. It has happened to me in two out of two re-entries while playing today, one on Eve and one on Kerbin.

Description:  After building a rocket with more than 8450 dV and weighing about 300 tons (fully loaded) and getting it to Eve's orbit, when trying to aerobraking to slow down the orbital velocity (quasi-circular orbit of about 110km Ap and Pe) and landing, the rocket, protected with two inflated HS-I heat shields, is destroyed due to the failure of the HS-I heat shield itself by overheating.

I've never tried it before today, so before guessing if it's related to the heat modification on re-entry from the last patch, I decide to test if it was simply a kracken attack.

So I try to repeat it but having the same rocket try to re-enter Kerbin from a quasi-circular orbit of about 120km altitude. In this case the inflatable heat shield did not fail, but it did show the visual warning of overheating. I took the attached screenshot of the moment (I didn't take it when it failed on Eve, I was too shocked to react).

Included Attachments:

EveLander03.json

[The Space Peacock]

@Jose Tortolamerged your report