No engine plume and vehicle phasing through terrain

[AlmightyM3]

Game Version​

2026.4.18.4206

Operating System​

Windows 11 Pro

System Info​

Processor: AMD Ryzen 7 5800X
RAM: 32 GB
GPU: NVIDIA GeForce RTX 3060 Ti, 8 GB VRAM

What Happened​

None of the engines on the default spacecraft in testing mode have visible engine plumes, although they still have the startup effects, sound effects, and heating effects. The rocket also seems to go through bumps in the terrain but not flat terrain.

What Was Expected​

Visible engine plumes and interactions with terrain features is expected as that is what occurred in previous versions, such as 2026.2.5.3428.

Reproduction Steps​

1. Start KSA in testing mode. (I have not tried other modes so I do not know if it also occurs there.)
2. Try starting any engine on the default craft, no plumes will be visible.
3. Upon deorbiting, the rocket does not interact with hills and bumps in the terrain.

Reproduction Rate​

Always.

Additional Info​

See attached photo for an example, I also have a video but seem to be unable to upload it.

 

[SToRME]

Same issue here.

CPU: AMD Ryzen 7 5700X
RAM: 32 GB
GPU: NVIDIA GeForce GTX 1070 Ti, 8 GB VRAM

 

[SToRME]

I've realized that the atmospheric engine in atmosphere does actually make quite a nice plume, but the vacuum engine makes nothing anywhere

 

[SToRME]

This is fixed for me as of the most recent patch (v2026.5.3.4264). I can now see exhaust plumes in all engines at all altitudes.

It's possible this was not even a bug, just unintended yet realistic behavior.

 

[Maxi]

I believe that vehicle phasing through terrain is to be expected because they are currently still working on better collisions that are not in the game yet

check out the dev-update on the discord by gravhoek: https://discord.com/channels/1260011486735241329/1296653251902443551/1481815929238196426

 

[gravhoek]

Phasing through the terrain on a flat surface in this way is not expected - do you have a save game where this happens?