Map & Tracking Station AP/PE are Dropping (Orbital Decay) When in Low Orbit of Some Planets/Moons

[SpaceGame123]

Is this what happened to you?

 

https://imgur.com/a/gAEqfVf

[James Kerman]

Overlapping topics have been merged.

[机械主教71号]

I had this also. Meanwhile, all the satges and engines can not be activated.

[Semicon]

Same here.  It is almost like a high altitude \ low atmosphere orbit decay.  Switching to ksc or time warping stopping it makes sense because the atmospheric effects should not affect the decay rate during that time (?).   It really does feel like a new team working on this rather than the veterans guiding it and pointing out their findings from KSP1.   If I could give the new team some advice:  Listen to the devs of KSP 1.   They made some mistakes, learnt from them and ended up with a pretty solid game, you guys have some really cool ideas, but things like this can be avoided (if it is remembered or documented).

 

[Kurtvw]

I have a lander which has ascended again to rendesvous with another craft at Mun.

Lander is trying to fly a lower orbit to catch up, about 13k X 13k meters.

When I do my circularization burn, I see new valid orbit, but PE and AP numbers are changing even if all engines are manually disabled.  Speed is also flipping about by a few M/ps.

So I hit time warp to force the orbit on rails, which works.  But then when I come down to 1x speed, the velocity changes and puts the craft back on its original suborbital trajectory.

Not sure if there is some corruption in the save, or if there is more to this.

Install is 0.1.1.0 21572 running on Windows 11
i7-9700k  32GB Ram
3070Ti graphics.

[jwenting]

Launched a vessel into a low orbit over Minmus (about 20x35km on a high inclination).

Orbit kept decaying fairly rapidly. 

KSP2 0.1.1, i7-10700, 32GB RAM, RTX3080, no mods

[CashedOut]

Confirmed, having same problem. Occurs with SAS only engaged, RCS only engaged, SAS and RCS both engaged, and without either SAS or RCS engaged. For me during most of the orbit, periapsis lowers and apoapsis increases at the same rate, except near the poles, where apoapsis increases with less change in periapsis.

The ONLY thing I've found that stops this is timewarp at 2x or greater - the issue only occurs in 1x time. Tried saving and returning to KSC, then resuming control via Tracking Station (BIG physics/ graphics lurch from previous orbit to one that put the vessel 5-6 kilometers closer to Minmus), and the issue persisted. Also tried saving and quitting game - problem (constantly lowering periapsis) reoccurred after I relaunched the game.

Build info: KSP2 0.1.1.0, i7-12700K, 16GB, RTX 3060, no mods.

[Razor235]

Interesting.  I didn't have this problem this time around, despite having it pre-patch.

 

Did you load any saves during the flight before the decay started?

[Starhawk]

Multiple overlapping bug reports merged.

[CashedOut]

On 3/17/2023 at 2:42 PM, Razor235 said:

Interesting.  I didn't have this problem this time around, despite having it pre-patch.

Did you load any saves during the flight before the decay started?

Ironically pre-patch I didn't have this problem, just the standard orbital jiggle.

Nope! I stayed with the craft all the way through until I got to Minmus orbit, no saves loaded.

[Tazooka]

I've noticed my MSS now has an orbit of 46000 x 48000, when originally it was 55000 x 56000

[Sea_Kerman]

This is happening to me too, got a quicksave of a craft that it's happening to, persists through quicksave/quickload

https://drive.google.com/file/d/1K8RfQJ5yPT2mey0gAh2CrWJQkAuSQHNl/view?usp=sharing

[机械主教71号]

Still having this problem after patch 0.1.1.

[TraumaBone]

As the title states, I am experiencing thrust or a change in my Delta V when I'm in low orbit around the Mun or any other body with not atmosphere. When I get below 50,000m, the AP and PE will start to change on their own. Engines and RCS are disabled. Even if I eject just a probe core with a battery and solar panel into the orbit, the AP and PE will continue to change, until eventually the craft will crash into the surface. This is making the game VERY difficult, as I can't survey the surface of anything from orbit or make stations/probes etc to orbit them. I have had this exact bug since the day release. Please help :D

[Kim Hanson]

Version: 0.1.2.0
Windows 11 Pro
12th Gen Intel(R) Core(TM) i5-12600K   3.70 GHz
NVIDEA GeForce RTX 3070
No mods

This has been persistent since the initial release.

When orbiting a moon or planet the AP and PE can change, usually downward, especially at lower altitudes.  It is as if there is an atmosphere slowing your vessel.  This can really raise hob when trying to land especially with tight fuel constraints.  The only temp fix I've found is to time warp.  Even the minimum warp is sufficient to stop the degrading orbit.

[Anth]

Merged a Bug Report.

[Anth]

@TraumaBone Merged your bug report with this one.

[Turbo Ben]

Reported Version: v0.1.3 (latest) | Mods: none | Can replicate without mods? Yes 
OS: Win 10 Home 64bit | CPU: Intel 11700KF | GPU: Nvidia 3090FE | RAM: 32GB DDR4 3600

 

Weve all come across the orbital decay bug, we all now what it is. In the last dev update, Nate said they had it down to being caused by compounding part wobbles.

So, I decided to put a command pod around the Mun and stage away all other parts leaving just the command pod. As it's a single part, there should be no wobble, and orbital decay should stop, right?

Well, unsurprisingly, orbital decay continued unchanged. However, there were a couple of funky goings on that might help shed some light on this.

Firstly, there was a wobble, a big one. Once all other parts were staged away from the command pod, it immediately began to wobble uncontrollably. Turn SAS off and the wobble stops (orbital decay continues though). Turn SAS back on and the wobble returns.

I also started getting the camera mode change notification being spammed, so rapidly that it is unreadable. Pausing the game shows the modes to be ground and orbital.

I have repeated this test with 2 seperate missions and loading up a quicksave after the inevitable crash into the Mun. It does it every time.

To recreate, send an "explorer" command pod to a low orbit of the Mun (I went for about 10Km). Make sure you stage away all other parts of the craft leaving just the exploror command pod.

P.S. I wouldn't recommend this for those that are sensitive to flashing images.

 

Included Attachments:

[sleepy_eb]

I can confirm confirm that this, or a similar bug is still present in 0.1.3 on my amd5800G with rtx2060

My orbital inclination changed during assembly around Kerbin. The first craft was way out of inclination once I had launched the second craft of the assembly making for an interesting rendezvous.

I did not have the same issue with the third launch to the combined craft. I also lost approximately 8000m/s of deltaV, but the orbit did not get any larger, it only changed inclination.

My craft was parked in a 90x100km, equatorial orbit.

[invaderrizz]

Reported Version: v0.1.3 (latest) | Mods: none | Can replicate without mods? Yes 
OS: Win 11 Pro 64bit | CPU: AMD Ryzen 7 3700x | GPU: Nvidia 3070FE | RAM: 32GB DDR4 3600

Still present for 0.1.3, just almost crashed into Eeloo when I was trying to pick out a good canyon.   Had a polar 30km circular orbit, and it decayed pretty quickly.  I played with time warp, and my PE/AP continued to change under 2 and 4x warp.  After I passed periap at about 12km, the changes reversed - my periap continued to increase while my apoap started decreasing.

[wefightforpeace]

This is still happening for me in low orbit around the Mun in 0.1.3.

[Filed.Teeth]

On 2/27/2023 at 7:19 PM, AstroClef said:

I documented this bug on all Non-Atmospheric Bodies:

 

I had forgotten all about this, I remember now being super impressed by how much work you had put into it so early.

lol.

Edited June 28, 2023 by Filed.Teeth

[apoch1999]

i hope this fixes my issue also, sounds related. in KERBIN orbit, if i time warp, the orbit stays the same on the screen as the vessel revolves around the body. making the orbit change and look like its "decayed" when it actually just.."slips" over

[herbal space program]

On 6/22/2023 at 1:35 PM, Turbo Ben said:

Weve all come across the orbital decay bug, we all now what it is. In the last dev update, Nate said they had it down to being caused by compounding part wobbles.

So, I decided to put a command pod around the Mun and stage away all other parts leaving just the command pod. As it's a single part, there should be no wobble, and orbital decay should stop, right?

Well, unsurprisingly, orbital decay continued unchanged. However, there were a couple of funky goings on that might help shed some light on this.

Firstly, there was a wobble, a big one. Once all other parts were staged away from the command pod, it immediately began to wobble uncontrollably. Turn SAS off and the wobble stops (orbital decay continues though). Turn SAS back on and the wobble returns.

I spent a fair bit of time analyzing this bug around Vall a couple of days ago, and what I concluded was that it will happen anytime you let a ship with two docked-together modules get closer than a certain distance, which varies from body to body, as @AstroClef documented early on.  IOW, I'm not sure you'd actually get the decay bug if you staged everything off before you ever reached that critical radius around Mun.   When I kept my Jool5 mothership at a safe distance from Vall, the lander (which is just one assembly) seemed to have no trouble going to the surface and coming back to that safe distance.  Once you've got it though, your whole craft will remain affected permanently, and you can only get rid of it by going back to a pre-bug save file.  The decay per se may actually go away if you leave the SOI where it happened, but whenever it happens it also corrupts your craft so that it will forever afterwards be plagued by phantom forces. These will become evident any time you go away from it and return or timewarp and then return to full physics.  My Jool5 mothership would practically shake itself apart. I think it actually has something to do with aberrantly creating big pent-up forces in docking interfaces, because the orbital decay bug is also perfectly correlated in my experience with the docking disaster one, i.e. once the big ship started to drift in its orbit, any subsequent attempt to undock the lander would make something really bad happen.

Edited July 17, 2023 by herbal space program

[Snips]

Problem still exists in 0.1.4.0.26521. Put a craft in a 10 x 20 km orbit around the Mun and the AP is rising while the PE is falling.