Does anyone still use the S.A.S. module?

[Fel]

Honestly, I don't see the point of S.A.S.

If it isn't A.S.A.S., I can do it manually. (And A.S.A.S. only helps partly in that)

(Of course, if you don't design your rockets to rotate well, or are too impatient to wait a few moments for it to turn, I guess SAS has its uses.)

Edited June 26, 2013 by Fel

[FlamedSteak]

Quite a bit. It helps stabilize ships during docking without wasting all your RCS fuel on spasms. It also helps keep rovers from flipping.

Crap, really? I've just got my new rover into Mun orbit and I'm fixing to land it tomorrow morning.

Also for the record I occasionally throw some SAS modules on early stage tanks for a bit of extra stabilisation during launch.

Especially if the launch vehicle is a particularly terrible design that I'm trying to salvage.

Edited June 26, 2013 by FlamedSteak

[Flixxbeatz]

Honestly, I don't see the point of S.A.S.

While that's abit true, SAS was actually like the ASAS before ASAS was added and implemented in this game.

[Frederf]

SAS parts are a Godsend when used on docking tugs.

[Brotoro]

I quit using SAS parts once I found out they don't add anything to my control inputs (and, in fact, fight against them).

[Dizzle]

I only use them on top of SRBs when I fire them without assistance from vectoring engines.

[Echostatic]

So, do SAS modules kill rotation, or assist in torque? I think I've read people saying both in this thread...

[redteddy23]

So, do SAS modules kill rotation, or assist in torque? I think I've read people saying both in this thread...

I thought that SAS will dampen any attitude change when you press t, that is any movement in yaw, pitch and rotation. This dampening is proportional to mass times the SAS torque of the all the SAS modules on your craft added together then divided by the total mass of the craft. ASAS, I think, acts as a PID Controller that will use all the control surfaces, RCS thrust, engine gimbaling and control pod rotational power to keep your craft pointing in a direction. The Avionics Package has different values from the standard ASAS that allow you to have a finer control of the change in attitude of your craft rather than simply trying to keep it pointed in the current direction.

I may be wrong on all this.

So I had a look at the cfg files and http://en.wikipedia.org/wiki/PID_controller

\GameData\Squad\Parts\Command

ASAS --- SAS parameters ---

Ki = 1

Kp = 0.6

Kd = 1

Avionics Package --- SAS parameters ---

Ki = 0.0

Kp = 0.2

Kd = 0.2

SAS --- SAS parameters ---

maxTorque = 20

Ki = 0

Kp = 5.0

Kd = 3.5

Mk2 Lander-can --- pod/rcs parameters ---

rotPower = 15

linPower = 15

Kp = 1.0

Kd = 1.0

So SAS does act as a PID controller well a PD controller anyway with and integral value of 0 it doesn't correct for heading changes over time and with high values for P and D it will correct for changes from the direction and precisely and quickly, at least that's how I understand it, I was never very good at control theory. The Avionics package, I am guessing from these values, acts like a very gentle SAS but without its own torque, just using control surfaces (and presumably all the other stuff I mentioned above).

So anyway to answer your actual question as the lander can shows it has rotPower to change rotation and linPower to change pitch and yaw, plus its a PD Controller. However, the SAS only has a maxTorque value that can only be used to stop changes in direction rather than help cause them.

Sorry for rambling and please tell me where I'm wrong.

[ComradeGoat]

My RSC space station tug is 2 RSC tanks with 8 RSC thrusters on it. Perfect for pushing big things around, but if I'd try to manouver the small thing alone (with RSC) while keeping it steady with SAS, it'd be impossible with ASAS (kicking it all over the place in trying to keep it steady). With normal SAS though it's pritty easy

Interesting idea. I'm currently using command modules (for the torque) with a single ring of X RCS thrusters as my tugs, which seems to work quite well, but they're heavy.

[LaydeeDem]

People playing the KSP Campaigns on the wiki are limited to SAS until the Mun Race during the Kerbollo Program when ASAS is developed:

https://wiki.kerbalspaceprogram.com/wiki/Campaigns

Why have I not heard of this yet?

[CaptRobau]

I think SAS and ASAS should be renamed. Right now the names give the impression that ASAS is just an upgraded version of the SAS with better capabilities. In actuality, both parts perform different tasks.

I agree. With the devs working on reaction wheel/ASAS stuff, that might happen sooner rather than later.

[psistorm]

I used them recently to stabilize a rover delivery system, which, despite my best efforts to center the CoM began tilting strongly whenever I put thrust on the main engines. That aside, I usually use ASAS now for my ascent stages to keep them in a nice, stable trajectory, despite a wobbly one.

But as was said before, that will soon be a thing of the past once 0.21 comes around and makes it all better

[Robbii6]

I was playing last night and noticed the S.A.S. module under the parts section and honestly forgotten about it; mainly because I haven't used it since around .11 (with the addition of the A.S.A.S.) and haven't noticed it since probably .14, so does anyone still actually use it?

yes all of the time, the A.S.A.S does not apply that much torque. the A.S.A.S is just supposed to use what is on the ship to stabilise it. it does stabilise but i tend , with bigger ships to use the S.A.S mods everywhere i can. it helps loads. with most ship you can get away with just using the ASAS but With lots of the SAS's you can you agility is enhanced greatly.

[Tobyz28]

I did some basic testing with SAS units and found them only useful if the center-line of the SAS unit is along an axis in line with the center of mass of the ship/station. Having 1 or 2 along each X/Y/Z axis was ideal and very noticeable when stopping rotation. SAS units further away from one of these axis's had minimal effect.

[Deadweasel]

So... Because both units serve different functions, is there a way to use BOTH on a craft, and then switch between one or the other? Say perhaps through action grouping? I'm not at my game rig at the moment or I'd be testing the idea...

[Flixxbeatz]

People playing the KSP Campaigns on the wiki are limited to SAS until the Mun Race during the Kerbollo Program when ASAS is developed:

https://wiki.kerbalspaceprogram.com/wiki/Campaigns

I will DEFINITELY do #15 on my save once I've progressed further enough.

[Frederf]

So... Because both units serve different functions, is there a way to use BOTH on a craft, and then switch between one or the other? Say perhaps through action grouping? I'm not at my game rig at the moment or I'd be testing the idea...

I really wish so but ASAS, avionics, SAS, etc. are always enabled when attached. There are lots of times when I wish I could disable ASAS and there might be examples when I would want an optional SAS.

[animalcross]

Don't think I've used it since .12.

[NeoMorph]

So... Because both units serve different functions, is there a way to use BOTH on a craft, and then switch between one or the other? Say perhaps through action grouping? I'm not at my game rig at the moment or I'd be testing the idea...

The only ASAS you can disable is on Bobcat's Orion mod. But as ASAS isn't really and Advanced SAS I just go ahead and use both on low torque rockets. ASAS handles the guidance, SAS handles stability.