Orbital Mechanics Broken

[mjl1966]

This is not a question, it is a bug report.  I have reliably reproduced this ten times with various craft, the last one being a full stock vehicle.  There are various symptoms that tell me the orbital mechanics model in the program are totally broken at this point, but a simple and obvious one to describe is this:

After TMI, the projected munar periapsis expands rapidly.  In my latest experiment, the projected periapsis started at 17.4K after TMI burn.  After letting it coast for just a few seconds, it expanded to 17.7K.  If I time accelerate, it stabilizes, but if I leave it in normal time, it continues to expand.  May not sound like  a big deal until I start doing unaccelerated time activity like exploring the surface of the Mun (which is how I discovered this bug in the first place.)

Once I'm in orbit around the Mun, my orbit further destabilizes.  I've seen both decay and "anti-decay".  On my last experiment, the orbit simply decayed for both apoapsis and periapsis,  But I have seen some scenarios where apoapsis actually increases over time.

Has anybody else seen this?  Is this a known bug?  Is it being worked on?

-MJL

 

 

 

 

[EliasDanger]

Well, Steve...I haven't had the problem myself, but I have heard among the forum people complaining about an Orbital Decay Bug. So, Steve, I thinks its a known issue...Steve.

 

 

Steve.

 

[Superfluous J]

This has already been reported and I believe a fix is already in place for the next update.

It's also not "broken," you can still do missions and orbit things. I'm doing a Grand Tour and while it's annoying to deal with, it's not game-breaking.

[Kertech]

I dunno it crashed my Duna ship (mercury 1)! Was in a 150*150 orbit, went to the loo, came back to find debris everywhere, last save took me back to before five ejection burns for some probes! I hope this one is sorted soon, I love the game but it's making it tricky to do anything!

[Renegrade]

As it's described in the OP, this is NOT the orbital decay bug.

11 hours ago, mjl1966 said:

Once I'm in orbit around the Mun, my orbit further destabilizes.  I've seen both decay and "anti-decay".  On my last experiment, the orbit simply decayed for both apoapsis and periapsis,  But I have seen some scenarios where apoapsis actually increases over time.

Has anybody else seen this?  Is this a known bug?  Is it being worked on?

I've noticed that landing struts/legs will cause that sort of decay/anti-decay.  For my typical four-legged landers, they can accelerate even a mid-sized station at upto 0.15m/s^2 at times, which can de-orbit 'em in very, very short order.   It doesn't always happen (especially on the initial entry into a scene) but after a landing and re-docking, my stations are usually going off to explore the cosmos or crashing into the surface on kraken drives.    I've confirmed this on a pure-stock install.    NB: It also imparts some fairly violent torque.

My workaround is to use cubic octags or i-beams or such for landing legs instead of the actual legs.  As a bonus, they're much stronger and don't randomly explode.  This of course doesn't help the unrelated orbital decay bug, but that one is incredibly slow and easy to overcome.

[Violent Jeb]

proabably worth mentioning that timewarp will likely stop this from happening. If you can remember to increase speed to 5x when you're just sitting around admiring your work. It'll be nice when the patch comes.

[mjl1966]

On 5/31/2016 at 1:54 AM, 5thHorseman said:

This has already been reported and I believe a fix is already in place for the next update.

It's also not "broken," you can still do missions and orbit things. I'm doing a Grand Tour and while it's annoying to deal with, it's not game-breaking.

Good to hear.  Thanks for letting me know.

On 5/31/2016 at 1:41 AM, EliasDanger said:

Well, Steve...I haven't had the problem myself, but I have heard among the forum people complaining about an Orbital Decay Bug. So, Steve, I thinks its a known issue...Steve.

 

 

Steve.

 

Across the darkness, that which had slept awoken.  That which had lain undisturbed became disturbed.  Across the void, it reached out with its mind.  They screamed.  They ran in terror.  They knelt down and prayed, but it was a pointless gesture.  Mostly, they asked, "Why?  Why have you invoked the wrath of Steve the Kraken?"

You were warned.

On 5/31/2016 at 1:11 PM, Renegrade said:

As it's described in the OP, this is NOT the orbital decay bug.

I've noticed that landing struts/legs will cause that sort of decay/anti-decay.  For my typical four-legged landers, they can accelerate even a mid-sized station at upto 0.15m/s^2 at times, which can de-orbit 'em in very, very short order.   It doesn't always happen (especially on the initial entry into a scene) but after a landing and re-docking, my stations are usually going off to explore the cosmos or crashing into the surface on kraken drives.    I've confirmed this on a pure-stock install.    NB: It also imparts some fairly violent torque.

My workaround is to use cubic octags or i-beams or such for landing legs instead of the actual legs.  As a bonus, they're much stronger and don't randomly explode.  This of course doesn't help the unrelated orbital decay bug, but that one is incredibly slow and easy to overcome.

Yes, this!  I'm glad to know that it's not just me and now I know why it's happening.  Landers were the first ships where I saw this happening.  Non-landers just decay, which just confuses the issue further.  I never would have figured that out.