SAS goes AWOL

[AeroGav]

KSP 1.2.2.1622

This sporadic bug has been driving me crazy.  It mostly seems to occur when launching spaceplanes - 15 to 20 minutes after takeoff, SAS silently stops making inputs to correct the flight path, right when you actually start to need it since you're getting out of the atmosphere.

Quitting the game and reloading from a save seems to fix it.

This image sequence shows what happens.   We're set to prograde and the nose is down and to the right of Prograde, and moving further in that direction.  However,  SAS is not applying any control inputs to correct this 

As you can see we have electrical charge, reaction wheels are enabled and set normal, and i'm stabbing alt + x for all it's worth.

SAS still does not feel the need to correct.

As we pitch past 90 deg nose down, it abruptly wakes up.  But not to pitch.   Instead it gives a hard bootful of left rudder.

As we swap ends, the nose goes past the radial out position.   It starts feeding in opposite rudder to kill the yaw.

Job done !  SAS appears happy with its work, and leaves our nose pointing this way.   Not quite prograde is it though?  What about my circularisation burn?   

In this example at least, it seems SAS stopped monitoring Pitch altogether.   When we went past 90 degrees nose down, the yaw angle display would have reversed, so it tried to fix that - and nothing else.

I have mods (stock visual enhancements), so i guess i have to post in this forum.  Does any long time player really play this game 100% stock?    I uninstalled mechjeb and kerbal engineer, in case they were causing it.   Due to the sporadic nature of the fault, it looked as though it might help, only to recur a few hours later.

 

[ZooNamedGames]

Does appear to be a career mode? As such your pilot's experience will impact their control. Also note your in fine control, so your inputs will start slow and grow to normal power unlike normal.

[DarkOwl57]

One more issue is that you could have run out of electric charge. The electricity required to move the reaction wheels could have just depleted itself. Try to add batteries or solar panels to increase your time to use the EC. For now, you could just burn the engine for a little bit and raise that amount right up.

EDIT: Oh god I'm an idiot how did i not see the resources page... Ignore this previous statement

Edited January 17, 2017 by DarkOwl57

[AeroGav]

1 hour ago, ZooNamedGames said:

Does appear to be a career mode? As such your pilot's experience will impact their control. Also note your in fine control, so your inputs will start slow and grow to normal power unlike normal.

Not sure about fine control, that seems unlikely as it's never affected me before.  However, that screenshot was from a sandbox flight.   A new monster spaceplane i'm testing, had this bug strike at 18 minutes and 68km - it had been coasting to AP for the past several minutes.

The next flight however, was uneventful.

[ZooNamedGames]

Well I only mentioned fine control since I saw it was active and sometimes it can cause me control issues as well.

If that's in sandbox then it skips a large number of potential issues and opens a much bigger question.

[Darth Pseudonym]

I think this may be a manifestation of something I've seen the last couple of days (after not playing for a few months, so no idea when it started).  All my longer ships are now spontaneously pitching down for no apparent reason -- in deep space, SAS off, time warp, they should be dead-still when they come out, but after a few seconds, they all start to slowly nose down (or up?) and if I leave it alone, they spin faster and faster....

The SAS seems confused about what's happening, if I turn it on.  It shows the arrows symbol that means it's trying to slow my spin, but the needles on the left side show they are not producing force in any direction.  I can manually stop the rotation, but it'll start right back up, so that hardly helps.

Edit:  Okay, update, I uninstalled KSP and reinstalled, and now the anomalous rotation seems to have gone away.  I have a sneaking suspicion that it might've been the gamepad control configuration that I was using was inputting a slight nose-down signal all the time, but I'm not sure.

Edited January 19, 2017 by Darth Pseudonym