Flight Accelerate under Timewarp still not working in some cases (Often in Large SOI's)

[jclovis3]

Reported Version: v0.2.0 (latest) | Mods: none | Can replicate without mods? Yes 
OS: Windows 10 Home 22H2 | CPU: AMD Ryzen 7 7800X3D | GPU: MSI Gaming GeForce RTX 4080 16GB GDDR6X PCI Express 4.0 | RAM: 128 GB DDR5-6000

What Happened:
While taking off from Minmus in a Northly direction, I used the time warp and noticed my Ap stopped changing. Fuel was still being consumed. The trajectory arc was also not changing.

Evidence:
I tried loading from a quick save and even restarting and this bug persists, so I'm attaching the quick save.

Video: 

 

 

Included Attachments:

BuggedSave.zip

Edited June 13, 2024 by The Space Peacock
Added video and reformatted text.

[Anonymous Bug Reporter]

Reported Version: v0.2.0 (latest) | Mods: none | Can replicate without mods? Yes 
OS: Windows 10 | CPU: 12th gen Intel Core i7-12700KF | GPU: msi RTX 3070 Ventus 2x | RAM: 32

when i engage timewarp with the dawn engine active, it stops accelerating my vessel

Included Attachments:

dumbsat.json

[negativeIQ]

Just suffered this bug using Dawn ion engine. It was ok while in orbit of Kerbol, which is good since it required 2 game days of burn to intercept Jool (I think carrying enough fuel for 45k of delta V might be excessive but hey). Once I encountered Jool it's now broken. It consumes fuel and electric charge, but orbit speed and AP/PE are unchanged. I need to do a 7.5 hour burn to stay in Orbit. I'm not gonna do that !

[Nighthawk1313]

Reported Version: v0.2.0 (latest) | Mods: none | Can replicate without mods? Yes 
OS: Windows 11 Pro 64-bit (10.0, Build 22621) (22621.ni_release.220506-1250) | CPU: Intel(R) Core(TM) i3-9100 CPU @ 3.60GHz (4 CPUs), ~3.6GHz | GPU: NVIDIA GeForce GTX 1650 | RAM: 16384MB RAM

Impact: Med

Frequency: happens every time with this certain craft. Haven't tested if this happens for every ion engine, or if it's just this craft in particular.

When burning with an ion engine, increasing the timewarp stops the effect of the ion engine, even though the engine is still burning. It seems that the game just doesn't register any thrust at all.

Bug should be reproducible with the top stage of the attached craft file after releasing the fairings and firing the top decoupler.

Included Attachments:

Desktop2023_12.24-16_00_37_01.mp4

LongrangeCommsMK1.json

[T-BENZIN]

I've encountered same bug with Dawn ion engine. It affects the vessel around Kerbin, but not other with methanox one around Duna.

Edit: I found out that this behaviour happens only when pointed prograde. Once I turn about 45 degrees away from prograde, burn under time warp works fine.

Edited December 25, 2023 by T-BENZIN
New info

[The Space Peacock]

@Nighthawk1313 merged your report

[Jaypeg]

I've seen problems with this, too

[ABCDEFG]

Reported Version: v0.2.0 (latest) | Mods: none | Can replicate without mods? Yes 
OS: Linux fedora 6.6.8-100.fc38.x86_64 | CPU: 13th Gen Intel(R) Core(TM) i5-13500HX | GPU: NVIDIA GeForce RTX 4050 Laptop GPU | RAM: 16GB

I expected ion engines to produce thrust under timewarp. They do not. Electric charge and xenon are consumed, but the engine produces no thrust under timewarap. When not in timewarp, the ion engine produces thrust. Other engines(chemical, nuclear) are not affected. I am playing on Linux through proton, but the bug occurs on Windows too.

Included Attachments:

ksp_bug.mp4

[Spicat]

@ABCDEFG, merged your bug report.

[Anonymous Bug Reporter]

Reported Version: v0.2.0 (latest) | Mods: none | Can replicate without mods? Yes 
OS: Windows 11 Home Edition | CPU: 12th Gen Intel Core it-12400 | GPU: RTX 3060 | RAM: 48 GB

After a while during a ongoing mission, engines of the vessel stop to work producing Thrust in Timewarp. This particular bug happend to me only so far, when Ion Drives have been involved. But the bug itself will kill all thrust in timewarp, even with a Nuclear Backupengine, thrust won´t be generated in timewarp (But fuel will be used up, as will electrical charge).

It has happen in differnt orbits, inclung Kerbin orbits, Duna Orbits, Jool Orbits and in this case, a Eve Orbit.

Technicly the craft is composed out of 2 seperate launches/ships, but I include the Interplanetary stage here with the Iondrive and Nuclear Backup Drive.

I included the savegame (thrust issues) not sure if you can even work with that or use anything meaningfull with that, its the save from the moment the thrust issues appeared (the start from the video file)

Thinks I tryed to workaround:

- Shutting Down Engines and Active again - Don´t work

- Quicksave/load - Don´t work

- Restart Game and Load - Don´t work

- Teleport Ship into another Orbit and try it there - Don´t work

- Undocking the second ship and try it again - Don´t work

 

Funfact: The Lander Engines still work when I undock them from the Interplanetary Stage and activate them (in regular and timewarp mode), so the bug itself seems only be situation and vessel specific.

Included Attachments:

KerbalSpaceProgram22023-12-2719-45-16.mp4

StarwayI.json

ThrustIssues.json

[Coffey]

Experiencing the same issue around Eve

[AliceBo]

Yeah the one time you really need timewarp during a burn is while using dawn engines for an interplanetary ship.

Shame this is exactly where it breaks..

Just had to do a 3.5 hour burn in real time to enter orbit around Duna. Luckily the game is now stable enough that you don't need to babysit and you can just do something else during the burn

[Kielm]

Reported Version: v0.2.0 (latest) | Mods: none | Can replicate without mods? Yes 
OS: Windows 10 | CPU: Ryzen 5800x | GPU: Rx6700xt | RAM: 32GB

Using Ion engine ("Dawn").

Attempting an ejection burn out of Kerbin's SOI:

1. Time Warp to before periapsis
2. Stop time warp
3. Throttle up
4. Engage time warp
5. Disengage time warp
6. Set throttle to zero.

Repeat steps 1-6 enough times and after several (5-6) orbits, thrust will no longer be produced at >1 time warp.  Curiously, throttling down allows time warp to be engaged again. Each subsequent orbit requires a lower and lower thrust in order to engage time warp. Saving & reloading does not rectify the issue. 

No mods. 

The craft is named Duna Probe I-14.

 

Included Attachments:

quicksave_1.json

Save2023-12-30.json

[The Space Peacock]

@Kielm merged your report

[Ashandalar]

Reported Version: v0.2.0 (latest) | Mods: none | Can replicate without mods? Yes 
OS: Arch Linux (via Steam Proton Experimental) | CPU: AMD Ryzen 9 7950X | GPU: AMD Radeon RX 7900 XTX | RAM: 2x16 GB DDR5 @ 6000 MT/s

I launched a satellite with a single Dawn engine into Kerbin orbit and used it to slowly raise the satellite's altitude over many orbits, thrusting during timewarp throughout. Eventually, the engine stopped providing thrust during timewarp, but still worked normally outside timewarp. The engine had access to plenty of xenon and electric charge, and the issue persisted even when I turned on infinite propellant and electric charge.

I've attached a short, self-contained video of the bug occurring below (observe that the periapsis only changes during 1x timewarp), but was also recording the entire session. Here's a rough timeline with links to relevant timestamps:

• The satellite reaches Kerbin orbit: https://youtu.be/q5ivXwtk_T8?t=4380
• I then spend half an hour raising the satellite's altitude over many orbits, making heavy use of time warp while the single Dawn engine is thrusting.
• I first notice that thrust is not being applied during timewarp: https://youtu.be/q5ivXwtk_T8?t=6355
• I quicksave / quickload: https://youtu.be/q5ivXwtk_T8?t=6438
• The issue then occurs inconsistently across several timewarps: the first timewarp after the quickload seems is normal, but the bug occurs again during the second, then the third is normal, then the bug occurs during the fourth, etc.
• I quicksave / quickload again, to no avail: https://youtu.be/q5ivXwtk_T8?t=6610
• I save and exit to main menu: https://youtu.be/q5ivXwtk_T8?t=6680
• The issue occurs inconsistently again: the first timewarp is bugged, the second is normal, then every timewarp thereafter is bugged.
• I restart the game entirely, which didn't solve the issue: https://youtu.be/q5ivXwtk_T8?t=7125

I've attached a save from after I stopped recording with a two-hour manoeuvre I am unable to complete because I can no longer thrust under timewarp with the craft.

Included Attachments:

DawnBug.mp4

escapeburn.json

[Spicat]

@Ashandalar, merged your bug report.

[Anonymous Bug Reporter]

Reported Version: v0.2.0 (latest) | Mods: none | Can replicate without mods? Yes 
OS: Windows 11 | CPU: 12700K | GPU: 3090FE | RAM: 64GB DDR5

 

1. When entering Eeloo SOI ion engine was throttled up.
2. It was observed that the orbit periapsis changed slightly whilst thrusting under 1x time, ie thrust was being produced.
3. The periapsis does not change when time is accelerated, ie it stops producing thrust. Resources are still used as though the engine is thrusting.
4. As soon as time warp was reset to 1x the thrust returned and the periapsis began to change again.

Loading old saves sometimes temporarily resolved the issue, but it always returned. Only when within the planets SOI.

 

 

[Adalah217]

Reported Version: v0.2.0 (latest) | Mods: none | Can replicate without mods? Yes 
OS: Windows | CPU: AMD Ryzen 9 5900X 12-Core Processor 3.70 GHz | GPU: NVIDIA GeForce RTX 3080 Ti | RAM: 48.0 GB

 

Severity: med, no workaround 

Frequency: Replicated 100% on save. Unable to use low thrust engine around Jool on this save. 

Description:  

When entering Jool's orbit, the craft cannot accelerate when using the xenon engine if time is being warped faster.

When activating the higher thrust engine and entering warp, the thrust is calculated correctly and as expected.

When activating the low thrust engines outside of Jool (before and after entering orbit), the thrust is calculated as expected both with and without time warp.

The issue is strictly low thrust and in Jool's orbit. 

 

Note the seemingly unrelated and separate issue regarding solar panels not generating EC, which is captured elsewhere by other threads. 

 

Edited January 2, 2024 by The Space Peacock

[The Space Peacock]

@Adalah217 merged your report

[Aodhan]

On 12/30/2023 at 5:56 PM, Kielm said:

Reported Version: v0.2.0 (latest) | Mods: none | Can replicate without mods? Yes 
OS: Windows 10 | CPU: Ryzen 5800x | GPU: Rx6700xt | RAM: 32GB

 

Using Ion engine ("Dawn").

Attempting an ejection burn out of Kerbin's SOI:

1. Time Warp to before periapsis
2. Stop time warp
3. Throttle up
4. Engage time warp
5. Disengage time warp
6. Set throttle to zero.

Repeat steps 1-6 enough times and after several (5-6) orbits, thrust will no longer be produced at >1 time warp.  Curiously, throttling down allows time warp to be engaged again. Each subsequent orbit requires a lower and lower thrust in order to engage time warp. Saving & reloading does not rectify the issue. 

No mods. 

The craft is named Duna Probe I-14.

 

 

Included Attachments:

quicksave_1.json

Save2023-12-30.json

 

 

 

Same here, at first my ion engine worked under warp at low Kerbin Ap. But after multiple passes to raise my Ap, when it reached about 2500km, the dawn engine stopped working under warp.

 

I don’t want to do a 3hour burn at x1 speed so Eve will have to wait..

Edited January 2, 2024 by Aodhan

[krbvax]

Reported Version: v0.2.0 (latest) | Mods: none | Can replicate without mods? Yes 
OS: Wine 9.0-rc3 on Linux | CPU: AMD Ryzen 7 | GPU: NVIDIA 3060 Ti | RAM: 32GB

(*) Note: this is a duplicate of the bug below - I'm filing a separate report to provide a reduced test case and hopefully useful observations, since I don't see a way to attach a save file directly to a post.

 

Problem: Under specific circumstances, engines under thrust produce no acceleration during on-rails time warp. This appears to be possibly due to a loss of floating-point precision, causing extremely small acceleration values to be rounded to zero.

In the attached test case, containing a simple craft with a xenon engine in a 2500km circular Kerbin orbit, acceleration on rails works only when the xenon tank has 0.219876t or less fuel. I can't find a way to display the current vehicle mass, but from calculations based on part mass shown in the VAB, this would be a total vehicle mass of 1695.876 kg. (In the file, the fuel level is set to 0.2199t, so it will cross the threshold after about 5 seconds of full throttle acceleration.)

Severity: Medium

Steps to reproduce:

1. Load the attached save file.
2. Press Z to set the engine throttle to 100%, and observe (in the orbital info window, or by switching to map view and pinning the Kerbin PE node) that the periapsis altitude begins to decrease.
3. Within 3 seconds, set time warp to 2x.
4. For 3 seconds (6 simulated seconds), observe the behavior of the periapsis altitude.
5. Set time warp to 1x.
6. Observe the behavior of the periapsis altitude.
7. Set time warp to 2x again.
8. Observe the behavior of the periapsis altitude.

Expected behavior: The periapsis altitude continues to decrease throughout all steps after throttling up.

Observed behavior: The periapsis remains constant during step 4, but decreases as expected during steps 6 and 8.

Included Attachments:

rails-accel-bug.json

[The Space Peacock]

@krbvax merged your report

[Anonymous Bug Reporter]

Reported Version: v0.2.0 (latest) | Mods: none | Can replicate without mods? Yes 
OS: Win 11 pro | CPU: Amd 3950x | GPU: Amd 5700xt | RAM: 32gb

Happens seemingly randomly after entering a new soi.  Solar panels in full sun, batteries fully charged.  Throttle doesn’t seem to make any difference.  Thrust animation and sound appear, but 0 thrust while time warped.  Thrust stops above 1x and returns at time warp 1x.  Fresh ksp2 install with no mods.  Save/restart makes no difference.  Sometimes fixed by exiting vessel to vab, tracking station, etc but not always.

Included Attachments:

[macson_g]

I experience the same in 0.2.0.0.30291. (Windows 10 (64 bit))

I was able to depart Kerbin, but I'm unable to perform the injection burn at Dune.

 

 

[TFA3393]

Probably my most disliked bug post 0.2.0.  Ion engines are close to unusable because of this.  Only work around I found was to set throttle to below 10 (which was odd) and even that stopped working after a little.

[jclovis3]

One issue I am noticing especially with larger ships is that going into or out of time warp greater than x1 causes a lag as the physics engine is shifting modes. I found more success if I avoid jumping straight into higher time warp cycles until I have successfully made it into x2 and waited for this delay to complete and the clock starts running again. Then I can move up into higher warp factors with no problem.