DibzNr Posted December 20, 2023 Share Posted December 20, 2023 (edited) Reported Version: v0.2.0 (latest) | Mods: none | Can replicate without mods? Yes OS: Windows 11 | CPU: AMD Ryzen 5 5500 | GPU: RTX 2060 | RAM: 40GB Severity: High Upper atmospheric heating (within the first 20km of Kerbin's atmosphere) seems to be oddly brutal, quickly building up heat and destroying most parts with even relatively low heat tolerances, particularly small and medium wings which are usually destroyed within the first 5km of the atmosphere, this issue currently renders most spaceplane designs much more difficult to use in missions as they are simply incapable of surviving atmospheric re-entry without propulsively slowing down to a safe speed to survive this atmospheric layer, which is highly impractical. I also experienced nearly identical results on Laythe, except even quicker. This is clearly an issue with the upper atmospheric layer, as the small wings are capable of surviving all the way up to 1.8km/s in the lower atmosphere (Where the air is much denser and therefore heating should be much worse), once this upper atmospheric layer is broken through heating drops off and returns to what would be expected, as shown in the attached video (Notice that the heat is dropping even through the craft has slowed by less than 100m/s). The lack of re-entry visuals in the video may be related to me teleporting into orbit, not entirely certain, could possibly be a separate bug. Included Attachments: Demonstraing the small wings "true" heat tolerance in the lower, much thicker atmosphere, they only just fail at around 1.8km/s (Air is much denser here, so they should at least be making it a good amount into Kerbin's atmosphere before exploding during reentry) Reentry time-lapse (5x speed), showing the wings overheating in the upper atmosphere very quickly and then mysteriously beginning to cool down after passing 50km despite barely losing any speed and being in thicker air. ksp2_x64.exe2023_12.16-22_18_53.16(1)-Trim.mp4 Edited December 22, 2023 by DibzNr Link to comment Share on other sites More sharing options...
Vl3d Posted December 20, 2023 Share Posted December 20, 2023 I don't feel like this is a bug. I like the new heating behaviour - it is far more realistic. You should not be able to do re-entry without a heat shield or using a space-plane at deep angles. Link to comment Share on other sites More sharing options...
Abelinoss Posted December 20, 2023 Share Posted December 20, 2023 1 minute ago, Vl3d said: I don't feel like this is a bug. I like the new heating behaviour - it is far more realistic. You should not be able to do re-entry without a heat shield or using a space-plane at deep angles. Definitely a bug. When launching a rocket I that after I passed 60km my capsule suddenly started to heat up. That's just not how it should be. And on reentry I almost explode around 60km, and then it cools down a bit before the real reentry heat around 25km Link to comment Share on other sites More sharing options...
Vl3d Posted December 20, 2023 Share Posted December 20, 2023 11 minutes ago, Abelinoss said: Definitely a bug. When launching a rocket I that after I passed 60km my capsule suddenly started to heat up. That's just not how it should be. And on reentry I almost explode around 60km, and then it cools down a bit before the real reentry heat around 25km Player is doing 2300 m/s with wide wings at 50 km in the video. Also the photo shows 1800 m/s at 10 km. Why should those parts not blow up? Link to comment Share on other sites More sharing options...
Abelinoss Posted December 20, 2023 Share Posted December 20, 2023 1 hour ago, Vl3d said: Player is doing 2300 m/s with wide wings at 50 km in the video. Also the photo shows 1800 m/s at 10 km. Why should those parts not blow up? I'm not reacting to his video, but my own experience. It is definitely not normal that you heat up to the point of exploding at 60km. 1800m/s at 10km is certainly ingredients for boom Link to comment Share on other sites More sharing options...
TheLastEmpire45 Posted December 20, 2023 Share Posted December 20, 2023 The official changelog says that the reentry behavior is different from KSP 1 and is subject to change so this is technically an issue of balance, not a bug. Link to comment Share on other sites More sharing options...
nupp Posted December 20, 2023 Share Posted December 20, 2023 My probes keep overheating and exploding during ascent despite being in a faring. It is especially odd because the heat continues to build up even when I am at like 60 km altitude, there are no heating sounds or effects playing, engines are off, and somehow, the various parts that are within the faring are continuing to build up heat and eventually explode. Not sure if the bug is with the farrings or the heating system itself, but probes have been entirely unusable for me because of this. Link to comment Share on other sites More sharing options...
Anonymous Bug Reporter Posted December 21, 2023 Share Posted December 21, 2023 Reported Version: v0.2.0 (latest) | Mods: none | Can replicate without mods? Yes OS: Windows 11 Pro | CPU: Ryzen 9 7950x | GPU: RTX 4090 | RAM: 32gb cl32 6000mhz (@4800) The z-100 radial rechargeable battery overheats when reaching orbit, happened to me traveling at about 2000 m/s at 65k altitude. This didn't happen in the first game and I'm not quite sure its a bug but the overheating seems to be a bit exaggerated. The overheating didn't even start/show up until about 45k altitude, after acceleration had stopped. Included Attachments: Link to comment Share on other sites More sharing options...
Quasar_ Posted December 23, 2023 Share Posted December 23, 2023 I think this issue can be seen more clearly when trying to land on eve. Coming in from a low eccentricity orbit wtih a Pe above 85km. my heatshield was thermally overloaded. Dipping into the very tip of Jool was fine though for some reason Link to comment Share on other sites More sharing options...
KiithSomtaaw Posted December 23, 2023 Share Posted December 23, 2023 On 12/20/2023 at 1:46 PM, Abelinoss said: I'm not reacting to his video, but my own experience. It is definitely not normal that you heat up to the point of exploding at 60km. 1800m/s at 10km is certainly ingredients for boom Something like that? 4th attempt Link to comment Share on other sites More sharing options...
Jeq Posted December 27, 2023 Share Posted December 27, 2023 Reported Version: v0.2.0 (latest) | Mods: none | Can replicate without mods? Yes OS: win 11 | CPU: I7 | GPU: RTX 3080 | RAM: 32 It feels that atmosphere is too thick or atmosphere is unrealistic hot at edge of atmosphere. Parts overheat very easily, i got entry video at Duna altitude 40km and speed of 1500m/s, so i expect this overheat to be less than same situation at Kerbin, still parts explodes. Fuel tanks, smaller wings. Included Attachments: Link to comment Share on other sites More sharing options...
Spicat Posted December 27, 2023 Share Posted December 27, 2023 @Jeq, merged your bug report. Link to comment Share on other sites More sharing options...
WingC3 Posted December 28, 2023 Share Posted December 28, 2023 More heating, in and of itself is not an issue. However, a constellation of other items are combining to make it an issue: 1. More heat at an equivalent altitude as compared to KSP 1 (ok on its own) 2. Less drag at an equivalent altitude as compared to KSP 1 (also ok on its own, but problematic in combination with 1) 3. Inflatable heat shield and fairings NOT working as expected. The inflatable heatshield is overheating and the fairing is not actually shielding components within it. All three of these taken together renders aerocaptures basically impossible at this time. If that wasn't the goal then I think at least 2 of these need to be fixed. Link to comment Share on other sites More sharing options...
kojot Posted December 29, 2023 Share Posted December 29, 2023 (edited) My space plane big wings explode just before my vessel ap gets above 70km. something is odd here. Not during reentry but during start! Edited December 29, 2023 by kojot Link to comment Share on other sites More sharing options...
jcheung9941 Posted December 30, 2023 Share Posted December 30, 2023 had a couple of engines and tanks go from no heat bar to exploding in upper atmo during aerobraking maneuver at around 50k... which had i seen a heat bar i would have fired the engines! Link to comment Share on other sites More sharing options...
Jeq Posted January 3 Share Posted January 3 (edited) Can someone test if game has just an ablator check, only without any ablator this bug happens? I had same kind of problem at EVE enter at edge of 90km, when i added ablator then bug didn't happen. There definetly wasnt enough of heatshields to make anything remarkable for physics. Could be some error in normal parts termal capacity or ratio of drag, because even most massive fuel tanks heats up very quickly. Edited January 3 by Jeq Link to comment Share on other sites More sharing options...
kdaviper Posted January 3 Share Posted January 3 What might be happening... The fairing is heating up in lower atmosphere Then transferring heat to the attached part slowly until equilibrium. Link to comment Share on other sites More sharing options...
Mikki Posted January 3 Share Posted January 3 @DibzNr Your plane is hitting Mach 5.5 (6`700 km/h) at 10 km altitude, on earth steel alloys melt away and even titanium planes melt away at this altitude... it is correctly calculated by a engineer. Downvoted, sorry Link to comment Share on other sites More sharing options...
DibzNr Posted January 3 Author Share Posted January 3 (edited) 2 hours ago, Mikki said: @DibzNr Your plane is hitting Mach 5.5 (6`700 km/h) at 10 km altitude, on earth steel alloys melt away and even titanium planes melt away at this altitude... it is correctly calculated by a engineer. Downvoted, sorry On 12/20/2023 at 2:04 AM, DibzNr said: Demonstraing the small wings "true" heat tolerance in the lower, much thicker atmosphere, they only just fail at around 1.8km/s (Air is much denser here, so they should at least be making it a good amount into Kerbin's atmosphere before exploding during reentry) That was to demonstrate the fact that the wings could sustain those sorts temperatures in the dense atmosphere for prolonged periods of times, I was never implicating that the wings overheating there was somehow incorrect, for them to be able to take that heat in the lower atmosphere and then almost immediately overheat and explode in the upper atmosphere travelling just 300m/s faster when the air pressure up there is less than a few pascals is absurd Edited January 3 by DibzNr Link to comment Share on other sites More sharing options...
Mikki Posted January 3 Share Posted January 3 (edited) @DibzNr I have read your answer, might be an oversight somehow, hard to tell what wing parts consider in the game code. Edited January 3 by Mikki parts Link to comment Share on other sites More sharing options...
Jeq Posted January 3 Share Posted January 3 Todays trials and errors: Structucal node which has 2000k temperature tolerance blows up among first pieces at eve edge. Luxury heatshield which has 1700k temperature tolerance blows up among first pieces at eve edge. (It really doesn't seem to be heatshield.) Link to comment Share on other sites More sharing options...
kdaviper Posted January 3 Share Posted January 3 44 minutes ago, Jeq said: Todays trials and errors: Structucal node which has 2000k temperature tolerance blows up among first pieces at eve edge. Luxury heatshield which has 1700k temperature tolerance blows up among first pieces at eve edge. (It really doesn't seem to be heatshield.) They may have high heat tolerance, but do they have enough thermal mass? 6 hours ago, Jeq said: Can someone test if game has just an ablator check, only without any ablator this bug happens? I had same kind of problem at EVE enter at edge of 90km, when i added ablator then bug didn't happen. There definetly wasnt enough of heatshields to make anything remarkable for physics. Could be some error in normal parts termal capacity or ratio of drag, because even most massive fuel tanks heats up very quickly. That's kind of the point of an ablative heart shield though. Without ablator you might as well just stick on a structural panel Link to comment Share on other sites More sharing options...
Jeq Posted January 3 Share Posted January 3 20 minutes ago, kdaviper said: They may have high heat tolerance, but do they have enough thermal mass? That's kind of the point of an ablative heart shield though. Without ablator you might as well just stick on a structural panel Yes ofcourse but there is bug in game and it feels ablator gets rid of that bug, no matter of placement. Link to comment Share on other sites More sharing options...
hatterson Posted January 4 Share Posted January 4 To run some tests I put together a simple craft to test, An mk3 pod with the inflatable heat shield below and dropped it on a very thin pass into Kerbin's atmosphere. AP = 86752, PE=55,662. I was entering the atmosphere at ~2105 m/s surface speed. I did a quick save before entering so I could repeat it over and over again. On repeated tests, the heat bar would start showing up around 64-65km and the shield would blow up around 60-60.5km. I then tried a *much* steeper profile. AP = 300km, PE = -80.5km. This one repeated decelerated totally fine with zero heat bars. I was entering the atmosphere at ~2200 m/s surface speed. I performed test 1 again with an ablative heat shield and it performed totally fine, although it did ablate a total of .25 T out of the 2 T of ablator which seems like a lot. By comparison a very aggressive Mun re-entry (AP = 15,000KM which is past the Mun, PE = -51462m aka inside Kerbin's surface), entering Kerbin's atmo at ~3k m/s only ablated 0.06 of the 2 T before slowing to a nominal speed. I did get a heat bar on this, but it survived. So in conclusion, the inflatable heat shield appears to be messed up and upper atmosphere is doing weird things. Pancaking into Kerbin from the Mun should absolutely be a more significant re-entry event than barely grazing the upper atmosphere from LKO. Link to comment Share on other sites More sharing options...
dandoesstuff Posted January 4 Share Posted January 4 lmao i assumed 35km for laythe reentry wasn't too bad i think you can tell what happened after Link to comment Share on other sites More sharing options...
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