Low Speed Target SAS

[Daveroski]

While I am here...

At low speeds prograde and retrograde become unselectable  when using the SAS in Target mode.
I can still aim for either manually but not with SAS.

Was this lack of function by design?
If so what was the silly idea behind it?

 

D.

 

[VoidSquid]

For speeds below 1 m/s, SAS switches always to hold from retro/pro, be it target or surface mode.

[Daveroski]

6 hours ago, VoidSquid said:

For speeds below 1 m/s, SAS switches always to hold from retro/pro, be it target or surface mode.

I just said that.
If I can see them on my nav ball I should be able to select them with SAS.
Now that we have established the question how about some answers for the reasoning behind it?

 

[InfernoSD]

I imagine it has to do with the volatility of speeds below 1 m/s. If you rendezvous with something, rotating with RCS thrusters can send your prograde marker flying. It could even lead to a feeback loop where your vessel never actually reaches the prograde marker. Or if  you land on a moon, you don't want SAS to continue targeting retrograde when your landing struts bounce you slightly upward.

I think taking this control away from the player is a bad idea personally. For the same reason, the prograde and retrograde and manuever markers disappear at below 0.1  m/s, even though it would be desirable to still see them.

[VoidSquid]

18 minutes ago, Daveroski said:

Now that we have established the question how about some answers for the reasoning behind it?

Now that is a question better to ask the developers.

[Daveroski]

12 hours ago, InfernoSD said:

It could even lead to a feeback loop where your vessel never actually reaches the prograde marker. 

This is nonsense.

12 hours ago, InfernoSD said:

If you rendezvous with something, rotating with RCS thrusters can send your prograde marker flying.

I always turn off rotation on RCS thrusters in space and only use gyros. The only time I use RCS for directional control is when I am re-entering with a spaceplane to keep the nose pointing in the right direction while airbraking.

12 hours ago, InfernoSD said:

Or if  you land on a moon, you don't want SAS to continue targeting retrograde when your landing struts bounce you slightly upward.

Switching when speed in a given direction becomes zero or even minus is one thing. Switching just because your speed falls below a positive number is unhelpful at best.
I always felt it smarter to switch to Radial-Out just before touch down then I can gently settle onto a steep slope without sliding down a hill.

 

12 hours ago, VoidSquid said:

Now that is a question better to ask the developers.

Which is why I put it in the tech support area. It is a technical function which to me, currently makes no sense.

 

I use an unmanned probe for data gathering for my stations.
Because I can get the probe thrust down to RCS speeds I don't really need RCS on a probe to dock with the station.
Problems only arise if I apply slightly too much thrust so that I don't come to an relative stop.
Simply selecting Target/Retrograde on the SAS would be a huge help but as Target/Prograde and Target Retrograde become unselectable at low speeds, it becomes problematic.
I have to manually point at these directions and it is slower than SAS would be.
This magnifies the error of the overshoot.
The question I always ask myself when this situation arises is "Why make them unselectable?"

I just have to know. The puzzle is taxing my logic.
I'm even starting to think that it isn't by design and that it simply hasn't been "fixed" yet.

 

D.

 

Edited February 5, 2021 by Daveroski
typos

[Guest]

It's definitely by design, and it's definitely because of the volatility. You wouldn't want your craft to back-flip if you braked a little too hard and went to -0.001 m/s by mistake? 'Cuz that's what it would do if it wouldn't auto-switch at low speeds.

[OHara]

The changelog from version 1.0.0 confirms that reason

- SAS now disengages autopilot modes automatically (and falls back to stability assist) in cases where the target vectors would change very rapidly.

Strictly speaking, they should say when the velocity is very small the direction of the target-velocity vector can change rapidly, if you have any kind of thruster active.

It might fun to play with the old way, or there might be niche application, so I looked to see if the 1.0 m/s was a parameter somewhere, but could not find anything.

[VoidSquid]

4 minutes ago, OHara said:

It might fun to play with the old way, or there might be niche application, so I looked to see if the 1.0 m/s was a parameter somewhere, but could not find anything.

Unfortunately, as per my understanding, this couldn't be changed (reverted) using a MM patch, being a core game mechanic .