Bug #2049
Orbital Hell's Kraken (theory and reproduction steps included)
100%
Description
The Hell's Kraken. While many people are familiar with the effects it has, I actually managed to execute it in a way which can be reproduced:
1. Get to a point of orbit where you have a low orbital speed
2. Use low-thrust engines (I used 3 of the orange radials) to nullify your orbital velocity (I was trying to drop in on Kerbin, after having cycled some crew near Minmus)
3. Time accelleration (probably other rails would work as well, like saving, but I used TA)
4. ???
5. Hell's Kraken
I had a handful of mods installed, but none of them affect the physics of the game. Notably, I had MechJeb, which helped me with nullifing my orbital velocity (Translatron might work, but I SmartASS'd to retrograde).
My theory is based on the events of what happened in the Kraken - my velocity went to NaN, which is probably the root cause of the Kraken. I'm thinking that there is something in the on-rails physics which divides by orbital velocity; this was practically zero, which would result in the floating point returning NaN. Then, operations on a NaN return another NaN. This would get propogated throughout the physics, and eventually result in a complete breakdown.
In a related, but not nearly as severe bug, with respect to NaN, if one matches a target's orbital plane well enough, the angle between the two can become NaN°; I haven't seen any odd side effects of this however.
A potential fix would be to establish more checks for zero and NaN in the rail physics.
Related issues
History
#1
Updated by TruePikachu about 10 years ago
Updated by - Status changed from New to Confirmed
- % Done changed from 0 to 10
After a lot of struggle, I confirmed in Vanilla. I recommend either very experienced players or people with a joystick to do Vanilla testing, due to how easy it is to screw up your velocity vector on manual, but the cause is not from a mod, so MechJeb can be used to help with testing since it is less likely to bork the vector.
Also, after a slight bit of searching online, I found http://redd.it/1ikd35 , which confirms the bug for other people. However, that test was wrt to the Sun, while my test was wrt to Kerbin, so it is likely that the body is independent of the result. For the record, I also experienced a full graphics breakdown, as did the poster.
Fakeedit: http://redd.it/1he2dz confirms Kerbin for someone else. Someone with more experience should probably see what happens if e.g. debris hits zero when on-rails and unloaded. If it results in the Kraken, I'd request priority elevation by a single level, due to how uncontrollable debris orbits are (as in you can't control it, and it is a random chance it would end in a crash).
Realedit: Just realised my OP is slightly inaccurate.
+x/+-0=+-oo -x/-+0=+-oo oo-oo=NaN
where "+-" is plus/minus, "-+" is minus/plus, and "oo" is infinity. Sorry for all the edits :(
#2
Updated by Ted about 10 years ago
Updated by - Status changed from Confirmed to New
- % Done changed from 10 to 0
Very interesting, will give this a check over.
Just as a note, please don't confirm your own issues or report ones that you can't initially reproduce in stock - glad to see you could though!
Thanks.
#3
Updated by Dinokin about 10 years ago
Updated by i have a similar problem too when i switched from one ship to another (both are geostationary satellites) during the time acceleration and when the target loaded, it broked into hundreds of parts
ps. i didn't try to reproduce it, i became very pissed after this episode and ragequit from the game
#4
Updated by TruePikachu about 10 years ago
- Status changed from New to Confirmed
- % Done changed from 0 to 10
I marked it as confirmed because I found that other people have experienced the same issue under extremly similar circumstances - see the second Reddit for near-identical setup.
#5
Updated by TruePikachu about 10 years ago
err...I didn't actually mark it as confirmed in the combobox just then, what the heck.
Dinokin: That seems like Deep Space Cthulu, which is completly different. I didn't just get ships destroyed, no, the entire UNIVERSE unwraveled (even the starry skybox thing vanished).
Also, I actually don't have a confirm on the ships destroying themselves, just the universe.
#6
Updated by hermes47 about 10 years ago
Updated by - Status changed from Confirmed to New
- % Done changed from 10 to 0
TruePikachu wrote:
err...I didn't actually mark it as confirmed in the combobox just then, what the heck.
In that case I'll fix it for you.
Anyways, i've had a quick go at reproducing it but no luck thus far. I have a few more ideas to test out that I'll get around to in the next few days or so.
#7
Updated by Squelch almost 9 years ago
Updated by - Related to Bug #2501: Quicksave during landing on Pol - ship explodes on quickload, stays motionless in space. Game locks up. added
#8
Updated by Squelch almost 9 years ago
- Related to Bug #5235: Ship quicksaved below 700 m above terrain on Pol is destroyed on quickolad added
#9
Updated by TriggerAu almost 8 years ago
Updated by - Status changed from New to Needs Clarification
#10
Updated by TriggerAu over 7 years ago
- Status changed from Needs Clarification to Closed
- % Done changed from 0 to 100
Closing this report out for now. If you find it is still occuring in the latest version of KSP please open a new report (and this one can be linked to it.) For best results, the wiki contains really useful info for when creating a report http://bugs.kerbalspaceprogram.com/projects/ksp/wiki.
You can also ask questions about the bug cleanup in the forum here: http://forum.kerbalspaceprogram.com/index.php?/topic/143980-time-to-clean-up-the-bug-tracker/ and tag @TriggerAu to get my attention