Flight Not slowing down on reentry

[Davidian1024]

1 minute ago, mucco said:

I am at a total loss as well. How could it happen that such a basic test case is missed after an aero rework? I could picture it if nothing about aero or landing was touched, but...

FWIW, I can easily see how this would be missed.  If this dragless effect is truly limited to the command pod parts, I think it would actually be unlikely to encounter it.  It's not normal to reenter with nothing other than a command pod.  You're probably going to attach at least a parachute.  ...or a heat shield.  ...maybe RCS thrusters.  If those parts still have drag.  Then I think you'd never notice.

Also, saving/loading before it would happen has seemed to prevent it from happening for me.

[WingC3]

3 hours ago, Buzz313th said:

Fresh vehicle from a new campaign.

After installing 0.1.3, it took me less than 10 minutes to find this bug.  How did your Q&A team miss this?

I too am completely baffled as to how this was missed. Either no one took a flight at all after committing this change, or no one with an understanding of how it should work took a flight after committing the change.

So now there's no re-entry heating OR re-entry drag. Next Kerbin will lose its atmosphere and all life on the planet will perish...

[mucco]

9 minutes ago, Davidian1024 said:

FWIW, I can easily see how this would be missed.  If this dragless effect is truly limited to the command pod parts, I think it would actually be unlikely to encounter it.  It's not normal to reenter with nothing other than a command pod.  You're probably going to attach at least a parachute.  ...or a heat shield.  ...maybe RCS thrusters.  If those parts still have drag.  Then I think you'd never notice.

Also, saving/loading before it would happen has seemed to prevent it from happening for me.

It's not. I have encountered the bug before even staging. I had a 5 part vehicle: terrier engine, tank, decoupler, pod and parachute; still got the issue.

It does seem to go away by save/load for me. But this is so severe that I hope it's hotfixed away, at least.

Edited June 23, 2023 by mucco

[Buzz313th]

2 minutes ago, mucco said:

It's not. I have encountered the bug before even staging. I had a 5 part vehicle: terrier engine, tank, decoupler, pod and parachute; still got the issue.

It does seem to go away by save/load for me. But this is so severe that I hope it's hotfixed away, at least.

Good find. 

Also, when your in Kerbin upper atmosphere, try using SAS to rotate the craft 90 degrees and note the changes in deceleration from prograde, 90 degrees from prograde and retrograde.  For me, before a save, with nothing but a Mk1 pod and a nose chute, I was getting no deceleration retro, some decel prograde and the most decel at 90 degrees to pg.

[Davidian1024]

Here's an example where I'm not sure if things are working as they should or not.

At around 2:21 of the video I'm at my PE which is about 15km.  AP is dropping, but slowly.  I don't think I should've been able to get back to space.  But, I'm not sure.

https://drive.google.com/file/d/1Ly0wLfmq087IUqvuSbVuf-W5DWrUrpc3/view?usp=drive_link

[HebaruSan]

14 hours ago, MechBFP said:

Considering how easy this is to reproduce they can’t seriously be having troubles finding it, that would be embarrassing. 

40 minutes ago, Davidian1024 said:

saving/loading might be an awkward workaround.  I saved the game just before entering the atmosphere so I could try to reproduce the effect.  After loading the save, the above atmosphere skipping did not happen.  Everything seemed to behave normally.

Maybe the QA team is testing by cheating a pod into space on its own rather than launching a full mission, to save time. It kind of sounds like the drag cube occlusion is being stamped permanently onto the parts and not updated when the last bit is staged away (since a command pod would contribute no additional retrograde drag with a decoupler and tank covering its back). Presumably that caching isn't stored to the save file, so the proper drag cube would be calculated at load.

[TickleMyMary]

Reported Version: v0.1.3 (latest) | Mods: none | Can replicate without mods? Yes 
OS: Windows 11 | CPU: AMD Ryzen 7 5700X | GPU: RTX 2060 | RAM: 32

 

Craft rebounds back into space... It's there to see.

 

 

 

Included Attachments:

Edited June 23, 2023 by Anth12

[Palshife]

While not nearly as hilarious as OPs, here's a similar occurrence. This is a stock Kerbal X-2. Apoapsis is above Kerbin atmosphere, periapsis is below. No thrust, no RCS, no nothing. Giant flat cylinder pointed at the air and we see both the Ap and Pe increasing. "Air braking" is no more. Welcome to the age of "air thrusting." https://imgur.com/a/7TlelWy

[RalphKerman]

1 hour ago, Davidian1024 said:

FWIW, I can easily see how this would be missed.  If this dragless effect is truly limited to the command pod parts, I think it would actually be unlikely to encounter it.  It's not normal to reenter with nothing other than a command pod.  You're probably going to attach at least a parachute.  ...or a heat shield.  ...maybe RCS thrusters.  If those parts still have drag.  Then I think you'd never notice.

Also, saving/loading before it would happen has seemed to prevent it from happening for me.

The problem persists for me when I build a "normal" craft, not just the pod. I made a nice re-entry vehicle (parachute on top, capsule, heat shield) and the "zero drag" incident happens again exactly as described. The whole vehicle has (when pointed retrograde) zero drag and accelerates till very near the surface then experiences the "slingshot" back to orbit. So I doubt they "just did not test the extreme case of pod re-entry only". I am not on my PC right now so I can't test the save/load workaround yet (nice if it really works but unacceptable from a QA standpoint).

[RedderThanMisty]

2 hours ago, Davidian1024 said:

I don't think I should've been able to get back to space.  But, I'm not sure.

In KSP1, and earlier builds of KSP2, a good rule of thumb for me is that even for interplanetary returns, a periapsis of 35km, over double your altitude, is enough to slow down quickly without either burning up or skipping off the atmosphere.

Getting to space from 15km in an unpowered vehicle should be impossible, unless you have alot of momentum already pointing in that direction instead of towards the ground.

[TickleMyMary]

Two more instances of this bug...

https://www.youtube.com/watch?v=3FQHApzr-Jo

and

https://www.youtube.com/watch?v=vPJmWOPKMmw

One with a super steep angle and the other with a normal entry... Both get next to no drag and end up getting hoofed back up to the stars. Crazy bug to not have found/tested before release.

Edited June 23, 2023 by TickleMyMary

[handsomeness]

This happened to me with the stock default rocket on 1.3 on a fresh campaign. Mk1 pod didn’t slow at all during reentry 

[Lyneira]

I had a mission come back from an interplanetary trajectory from Eve. Before hitting the atmosphere, I ditched the rest of the spacecraft and piloted only a Mk1 "Tin Can" + Mk16 parachute into the atmosphere at a periapsis of 17 km and entering the atmosphere at 3589 m/s. I also experienced an implausibly low amount of drag, meaning I would have flown through the atmosphere at 17km periapsis and still exited above Kerbin escape velocity. It is possible to steer by keeping the pod at an angle to retrograde, but when I try to deflect the trajectory downward I soon lose control and hit the ocean still going over 2300 m/s. The steering results in the trajectory being deflected far more than should be possible.

Edited June 24, 2023 by Lyneira

[The Aziz]

A workaround for PE rising: Don't go retro/prograde. Try radial out for the time being. Seems to drop the PE as it should. The velocity problem still remains though.

I found yet another instance, as again, Mk1 command pod, went almost to the sea then started going back up - and also turned by 180 degrees and for the last bit of the trip, for no reason at all, I  was going west instead of east.

[Buzz313th]

On 6/23/2023 at 9:56 AM, WingC3 said:

So now there's no re-entry heating OR re-entry drag. Next Kerbin will lose its atmosphere and all life on the planet will perish...

This 'reentry drag/skipping off the atmosphere bug', has literally made the current state of the game worse than it was at EA launch.  Literally the game has become less playable after 3 patches. 

 

Can't make this stuff up.   

5 hours ago, The Aziz said:

A workaround for PE rising: Don't go retro/prograde. Try radial out for the time being.

So yaw or pitch 90 degrees from prograde or retrograde to slow for reentry, like, go sideways right?    What an incredibly embarrassing workaround.  I'm embarrassed for the  Devs. 

If I was the project manager at IG I would be firing people left and right, or resigning myself if it was my fault.  There are no good excuses.

I'm blown away that some KSP fans are still patient enough to remain positive and I used to be one of those fans.

FUBAR

Edited June 24, 2023 by Buzz313th

[whatsEJstandfor]

I was so confused by this bug that I felt compelled to make my own video for those who haven't seen it in action. So, to add to the chorus of concurrences of this bug, here you go: 

 

 

Edited June 25, 2023 by whatsEJstandfor

[Stankface86]

Had the same issue myself with the HS-125 (the small heat shield,) Was testing re-entry in a rocket I was building and it wouldn't brake. Once I hit the ground I slingshotted back up into space. Wasn't a super fast slingshot.

[RalphKerman]

6 hours ago, whatsEJstandfor said:

I was so confused by this bug that I felt compelled to make my own video for those who haven't seen it in action. So, to add to the chorus of concurrences of this bug, here you go: 

 

Very good video and with the commentary it is perfectly clear what is going on! This sums up the problem very well and is a nice compact demonstration of what happens. I am surprised about the sounds though. The mechanical "clanking" noise and that dramatic music when the pod skips up again is something I did not hear so far although I have all sound enabled and quite loud as well.

[SLS]

Capsules don't slow down, they appear to have zero drag when flying retrograde, but they do experience drag when side on. Is this a known bug? Hope I am not repeating previous posts...

[The Aziz]

More on the issue, though I literally have no idea what happened there:

https://i.imgur.com/lUScQOo.mp4

Separated, kept the speed, decoupler hit the pod, got destroyed and the pod pulled few hundred G's slowing down from 2000m/s to under 300 in 4 seconds.

[RalphKerman]

On 6/23/2023 at 12:25 AM, Dakota said:

We're investigating this issue internally. Will reply back if I hear anything or if the team requests more information. Thanks for the reports y'all!

Edit: heard back instantly, we'd working on reproducing this and would appreciate save and craft files if you have them.

I am sorry if the following sounds a bit negative or cynical.... but .... asking us for sending in craft files and "working on reproducing this" is hopefully just a copy&paste answer and not the actual intention?

YOU ship a stock rocket with the game (Kerbal K-2) that has this problem as has ANY OTHER rocket that can be the most simple rocket you can make in this game: 1 command pod, 1 decoupler, 1 tank, 1 engine, hell, skip the tank, just use a solid motor, so the most basic 3-part rocket anoyne can build in the game shows this problem. And you are asking for craft files to reproduce this bug?

Many people here have taken the time to make crystal clear youtube videos that show exactly what is going on. And the ones who did not do that described it very well in text form. That should really be enough as a starting point for investigations. Your answer is just a time-delay that makes me feel "They have no clue what is happening or the code is so messy they can't debug it properly".

I don't want to believe that..... And speaking of "believing": Your own creative director Nate Simpson wrote today in the posting about names of vehicles not being changeable that the team "believed to have fixed that bug in 0.1.3" but it was not the case. What shall we think if you are communicating that you "believe" in having bugs fixed instead of having run tests that "proof" that the bug was fixed (which you haven't (properly) since the bug is still there). Again: Messy codebase that is unmaintainable? Or severe lack of testing procedures and protocols?

I apologize, this was NOT a constructive posting but I am so sad and frustrated with the current game state that I just had to vent this thought. I will continue to write bug reports if I can add something valueable and refrain from ranting. I just love this game too much to give up on it. That's why this answer was emotional.

[HammerTyme]

This just happened to me earlier today..

I did a de orbit with my command pod. I noticed my speed wasn’t changing much as I got lower into the atmosphere. Still going about 2000 m/s  at 20k in altitude. It seemed like there was no air resistance to slow me down. Then at about 5k in altitude it started to lift like it had wings on it…. It flew up to 10k in altitude as if it had some kind of lift from wings on it.  Then it started to fall back down like normal.    That was the most bizarre bug I’ve encountered in this game so far personally. Lol. 

[HebaruSan]

5 hours ago, RalphKerman said:

And you are asking for craft files to reproduce this bug?

The QA team probably failed to reproduce it by cheating a command pod into space to save time, whereas the bug requires a decoupler and tank to be staged off the back of the pod (with no save/load before re-entry).

[The Aziz]

On 6/23/2023 at 6:54 PM, Davidian1024 said:

It's not normal to reenter with nothing other than a command pod.  You're probably going to attach at least a parachute.  ...or a heat shield.  ...maybe RCS thrusters.  If those parts still have drag.  Then I think you'd never notice.

Check my posts. On neither it's just a command pod. Still very much noticeable. 

[HammerTyme]

Any update on this yet? This is a pretty significantly game breaking bug… I really don’t want to wait another 2 months for the next update just so I can play the game as I was prior to this update.