What issues have people been having with SAS?

[Vycma]

Here is a seperate report on the control surface issue, if you want to vote on it:

https://bugs.kerbalspaceprogram.com/issues/21949

Edited April 23, 2019 by Vycma

[Guest]

On 4/20/2019 at 7:41 PM, ExtremeSquared said:

Using navball retrograde markers for surface rendezvous it auto-switches between orbit, surface, target/orbit and target/surface in a somewhat unintuitive and uncontrollable way. I still find myself sighting down the rocket body towards the HUD target marker rather than using the navball when doing precision landings on bodies that rotate with any speed.

I've never had retrograde work? It just points the nose away from the landing area...doesn't do anything to set you down at it, AFAIK?

[KerikBalm]

My biggest gripes with SAS, mostly related to planes:

#1) When it resets its zero on its own. If I want my plane to hold a 10 degree AoA, often the control authority is enough to do so, but the SAS will refuse to do it. When I elevate the nose, and try and lock in SAS, the nose will start to come down, SAS will weakly try to hold it up, and long before control authority maxes out, SAS just gives up and decides to lock in to some other point than what I set it at... what???

#2) A generally weak response: the response seems to be proportional to how far off the heading is compared to the desired heading - instead of whether the heading is moving towards or away from the desired heading. So when the desired heading gets 1 degree off, SAS will barely do anything to return to the desired heading. Instead I'd like SAS to try and vigourously fight a drift away from the desired heading, and when the heading starts returning to the desired heading, have it back off - otherwise it will start returning to the desired heading even faster, and obviously overshoot.

But mainly #1 is my biggest gripe... makes it very hard to just lock in a heading for large planes, then I need to fly them manually, and when they have many parts and it runs slow, its tedious.

[Merinsan]

On 4/21/2019 at 9:10 AM, Johnny Wishbone said:

Many moons ago, when KSP was but a young lad, SAS was a mighty force that would hold a craft straight and true. Then the “moar realism!” crowd started screaming and complaining and SAS eventually got gimped into the weak, pathetic, almost useless feature we have today.

The ironic thing is that most of the people who complained about SAS being “too powerful and not realistic” also use MechJeb to fly their craft for them. So, they never really used SAS in the first place (just substituted MechJeb for it), but they made darn sure to screw it up for everyone else by whining and complaining about it until they got their way.

Yeah, I’m a little bitter. How could you tell?

Actually, I think it used to be great when it was ASAS. Once they got rid of that, and allowed control while SAS was active, it just got screwed up. I had no problem turning off SAS when I wanted to adjust my course, it just took a little practice, and the occasional fireball of death, but it was solid as a rock.

9 hours ago, Victor3 said:

I've never had retrograde work? It just points the nose away from the landing area...doesn't do anything to set you down at it, AFAIK?

It takes some practice to use, but you can use the retro marker to guide the burns. Since your engines are on the back of the rocket (generally), you need to be pointed in that general direction for slowing down. Other than that, you want the retrograde marker roughly aligned to the forward vector marker. The retrograde target marker moves away from the direction you are facing.

Once you learn how to do it, it's not too hard, and you can get pretty close to where you want to go.

[Anth]

@Victor3 The picture shows an area that can be clicked on.

Its possible options are Surface, Orbit, or Target.

If its set to anything other than Surface when you are targeting retrograde you wont end up heading towards the ground in a way that will have you landing with horizontal speed equaling zero

Also when in atmosphere you might want to just use target assist when you get closer to the ground and are slowing down enough because the craft can start wobbling.

1

@KerikBalm Interesting about the control authority. You mean Authority Limiter for the Elevons/Flaps/Tail Fins/Canards?

Edited April 27, 2019 by Anth12

[Mignear]

The issue is more prominent when you're flying an aircraft. When you make a change to the heading, maybe pitch up, down, roll a bit, whatever, the SAS turns off completely for the duration that you are making a change in heading, which leads to things like your aircraft pitching down on its own as you roll or yaw.

The 3 axis should be independent, as in when you take control of one axis to change the heading, the other 2 axis should still have SAS working on them so you don't have to countersteer with a slight pitch when you just want to roll for a gentle bank.

[Anth]

@Mignear Interesting. That's totally true. I turned off yaw and roll and used either and the craft in question started pitching forward at the same rate to if I turn SAS off. (reaction wheels off)

I will post a bug report later on for it with video proof unless you want to do it?

[Mignear]

2 hours ago, Anth12 said:

@Mignear Interesting. That's totally true. I turned off yaw and roll and used either and the craft in question started pitching forward at the same rate to if I turn SAS off. (reaction wheels off)

I will post a bug report later on for it with video proof unless you want to do it?

Nah, its not a bug but rather, how the SAS works in the game currently. We just have to wait for Squad to improve this, or use mods to get the SAS we desire.

 

[Fraston]

None, except for how annoyingly difficult target SAS is to use as a missile computer.

[magenta]

I made a space plane and it works fine right up until I get to (sorta) space and then it starts a fast roll and I cant stop it even without SAS and with RCS it wont stop I might have to revert. SAS has almost never helped me. like the time it flipped my ship right before I landed

[Anth]

8 hours ago, magenta said:

I made a space plane and it works fine right up until I get to (sorta) space and then it starts a fast roll and I cant stop it even without SAS and with RCS it wont stop I might have to revert. SAS has almost never helped me. like the time it flipped my ship right before I landed

I have never had the problem you are talking about.

As for stopping its fast roll in space turn on timewarp as long as its not under some sort of power then the craft will stop spinning.

[Vanamonde]

On 12/18/2022 at 10:56 AM, magenta said:

I made a space plane and it works fine right up until I get to (sorta) space and then it starts a fast roll and I cant stop it even without SAS and with RCS it wont stop I might have to revert. SAS has almost never helped me. like the time it flipped my ship right before I landed

Sounds like you are relying on wings and control surfaces to hold attitude and when the air gets too thin for those to work well, your other control mechanisms are no longer sufficient. The center of mass might also be shifting as you burn fuel. A picture of the craft in question might help diagnose the problem. 

[magenta]

I think this is the craft I'm loading in to the game to check right now

https://imgur.com/a/Ts9oTdF

 

Edited December 20, 2022 by magenta

[Vanamonde]

Hmm. That's a lot of modded parts I don't recognize. If you rotate the camera around it the center point of your view defaults to the center of mass and you could see if it's too far back, and/or you could add some more control wheel parts. 

[MalneyKerman]

In rendezvous, when I point retrograde in target mode and timewarp on rails, my ship suddenly snaps to retrograde in orbit mode.  When I leave timewarp, my ship has to turn to point target-retrograde again.

[fulgur]

When you timewarp on rails, there is no longer any control of your ship. Your ship will continue in the exact same state and just move along the orbit.

As the ship moves along its orbit, the relative velocity between your ship and the other ship will change, and so your ship will have to rotate a little bit to match that. Since your ship is in rails mode, it cannot rotate using its reaction wheels or RCS. It continues pointing in the same direction relative to KSP's universal co-ordinates.

If your ship is changing direction at all in rails mode there is something very very weird going on with your KSP.

[JcoolTheShipbuilder]

the only really notable issue is that SAS sometimes locks for ingame years.. though now I realize that is what happens when you do negative physics warp, it causes SAS to unlock at the UT value you went to negative warp, which.. yea the game doesnt like it when you go at a negative phys warp value