Flight No fuel/deltav in staging column after undocking/decoupling when engine was disabled

[alien00785]

Reported Version: v0.2.0 (latest) | Mods: none | Can replicate without mods? Yes 
OS: Win 10 | CPU: Core i5 12600KF | GPU: RTX 4070 Ti | RAM: 32 Gb

 

First undock or decouple from an orbiting station with the landing vessel being the last active stage in the chain.  So far everything is normal. After then returning to the station, docking, transferring fuel to the lander, undocking, activating the lander engines it appears as no stage is active. I get no Delta V indication at the bottom right even though I can use the engines and the vessel is fueled. Also I can't plot any maneuver because ''vessel out of fuel''. 

 

Included Attachments:

Edited February 29 by Spicat

[centaurli]

Reported Version: v0.2.0 (latest) | Mods: none | Can replicate without mods? Yes 
OS: Win 11 | CPU: AMD Ryzen 5600x | GPU: AMD RX7600 | RAM: 16GB

 

Severity: Low

 

Steps to reproduce: Have two vessels docked (Mothership and lander for this example). Landers engine is deactivated. Undock the vessels and active the landers engine.

Expected behavior: Fuel/deltav status should be shown in staging column.

Observed behavior: Stage is still shown as not active. But tanks are full and the engine works and applies thrust.

Workaround: Activate vessels engine before undocking.

 

I compared the save files. When undocking with the deactivated engine, the StageID is -1, even after activating the engine. When activating the engine before undocking, the StageID is 2.

Happens every time, with different vessels.

 

Included Attachments:

Edited January 11 by DibzNr

[EngineeringWaffle]

Something to note about this that makes severity higher is that if your delta V is zero, you can't plan maneuvers. So whenever anything causes KSP to not correctly understand your vessel or where it's getting fuel from or where it's thrust is coming from or whatever, you completely lose the ability to plan manuvers at all. I think that it makes sense to alert people when their maneuvers exceed their delta V budget, but still allow them to be charted. Especially given the delta V calculations seem buggy right now.

[nasafan2841]

Reported Version: v0.2.1 (latest) | Mods: none | Can replicate without mods? Yes 
OS: Windows 10 | CPU: Intel i5-4690K @ 3.50GHz (4 CPUs) | GPU: NVIDIA Geforce GTX 3060 Twin Edge OC | RAM: 16.0GB DDR3

Severity: med

Frequency: med

so i was just doing my jool mission with my probe and for some reason this happened

i have no idea how this happened, although i think i have an idea on how it might happened 

step 1: start last stage engine without stage 2 decoupled

step 2: turn of last stage engine and decouple 2nd stage

step 3: timewarp while the engine is running

and then you should have it, a engine that no longer works when timewarping

 i tried saving and reloading but its still broken so i think there might be a workaround

Included Attachments:

2024-02-2712-37-08.mp4

[DarkDust]

I'm affected by this as well. Have a small station and a craft docked to it around Duna. No matter what I try (enabling/disabling engines, disabling port fuel feeds), when I undock the craft it reports 0 dV even though the tank is full. RCS also does not work in H/N direction, but does work in I/K and J/L directions. I can rotate the craft and manually fire the engine (after enabling it), then the craft moves but the camera moves roughly twice as fast and moves the craft outside the visible area. I cannot bring my Kerbals home any more as I cannot create a maneuver node. 

I can't seem to attach files here, have uploaded it to my server: quicksave_82.json. Craft is "(Combined)-16" (Poodle engine on craft is disabled in save game).

[Spicat]

@nasafan2841, merged your bug report. I suspect this is the same bug, thanks for the reproduction steps!

[JoeSchmuckatelli]

I had something similar.

Left a transfer craft in orbit of Mun.  Plenty of fuel (4k delta v).  Undocked and separated a lander - ran the landing mission, lifted off and docked with the transfer craft in orbit.  

No fuel - not even what was left in the lander prior to docking.

[The Space Peacock]

@centaurlimerged your report; kept your title. thanks for pointing out this happens when the engine on the undocked vessel is disabled!

[HyenaDae]

Still occurring for me even on the latest patch. Got three FT-100/200 tanks on a lander with an MK1 Pod +Spark and a docking port, but undocking (even with fuel transfer absolutely disabled) shows up as disabled/empty capacity which makes no sense

 

[Josh384331]

Reported Version: v0.2.1 (latest) | Mods: none | Can replicate without mods? Yes 
OS: Windows | CPU: i9-14900K | GPU: NVIDIA GeForce RTX 4080 | RAM: 64gb

Severity: med

Frequency: one-off

Description: When entering jool's SOI maneuver node was created.  before completing maneuver node, navigated to tracking station via button on bottom right side of map.  Navigated back to craft.  Maneuver node would not edit stating no fuel.  Staging menu showed no fuel.  Engine will still fire.   Reload attempted, no change, restart attempted, no change.  was not out of fuel before creating maneuver node.  

Included Attachments:

quicksave_2.json

[Vortygont]

Reported Version: v0.2.1 (latest) | Mods: none | Can replicate without mods? Yes 
OS: Windows 10 | CPU: Intel Core i7 9750H | GPU: NVIDIA GeForce GTX 1650 | RAM: 16 GB

Happened with me when I changed order of stage and activate stage. My Jool explorer probe had last stage with atmosphere probe on its top, but because I saved fuel, I decided to decouple atmosphere probe much earlier. I changed stage order and activated stage with atmosphere probe. When I came to the last stage of my main orbital vessel, it had full tank of fuel, but 0 dV. I opened save file to see what is wrong with my "Jool explorer" craft. I saw that it has "totalStageCount": 3. Maybe it's clue of the problem. I attached save and craft file

With craft file you can:

• Launch craft
• In orbit change stage order and decouple atmo probe
• Activate all stages on main orbital vessel
• Try to get bug

Included Attachments:

JoolProbe.json

autosave_2.json

[The Space Peacock]

@Vortygont merged your report

 

[Spicat]

@Josh384331, merged your bug report.

[nasafan2841]

21 hours ago, Spicat said:

@nasafan2841, merged your bug report. I suspect this is the same bug, thanks for the reproduction steps!

no problem

[magnemoe]

I have an variation of this bug but here its that dV reading is far to low after undocking. This has have happened twice, first time around Ike where my lander showed to have 75 m/s dV.
Now around Duna and it shows 1140 m/s, lander is fully fueled and standard dV fully fueled is 2800 m/s and fully fueled weight is 8.6 ton, dry mass is 3.6 ton. 

Later looks like its giving atmospheric dV or similar as burns also cost much less dV than they should. 
 

[Kayser]

On 2/27/2024 at 2:57 AM, EngineeringWaffle said:

Something to note about this that makes severity higher is that if your delta V is zero, you can't plan maneuvers. So whenever anything causes KSP to not correctly understand your vessel or where it's getting fuel from or where it's thrust is coming from or whatever, you completely lose the ability to plan manuvers at all. I think that it makes sense to alert people when their maneuvers exceed their delta V budget, but still allow them to be charted. Especially given the delta V calculations seem buggy right now.

Great suggestion and an insurance against future issues with delta-v calculations (which could also be affected by mods). Losing the ability to plan maneuvers is far more devastating than losing just your remaining delta-v remaining calculation (which in itself has some issues and might not have been correct, anyway).