What does "SAS-Equipped" mean?

[Themohawkninja]

I noticed that all of the control parts (excluding RCS ports obviously, and the inline reaction wheel) state that they are "SAS-Equipped". What does this mean? I thought it meant that they have reaction wheels in them, but the avionics package doesn't state any torque values for reaction wheels, so what is it?

[Supernovy]

SAS-equipped means it has the controller/stabiliser system in it, i.e. it will actually do something when you press 'T'.

If it lists torque values, then it means that it also helps you turn the craft (at the expense of electricity), and that if you have a SAS equipped part, it will use that torque when you press 'T'.

[NeoMorph]

It means the Kerbal Special Aerospace Service soldiers are on board...

SAS is the rotational stabiliser (think Gyros). ASAS is the flight computer part (or it was).

[Awaras]

So is there a difference between the SAS and the ASAS parts now? The ASAS description says it contains a flight computer, but I can't see any difference between their behaviors...

[Supernovy]

There is no longer a distinction between ASAS and SAS. SAS is the stabilisation when you hit 'T'. Both of the old ASAS parts contain that. Some parts now also have reaction wheels, for example the old 1.25m ASAS and SAS parts. The old SAS part, now inline reaction wheel, does not have SAS equipped so will only help during turning, and won't do anything when you hit 'T', unless you also have a SAS equipped part.

The command pods I think are also SAS equipped now.

[TMS]

Why on earth did they not take the opportunity to rename the ASAS/SAS parts sensibly? There's now a mish-mash of 4 versions of control parts.

[Xaver]

And the big ASAS has gotten no reaktion wheels, but both small have gotten them (ASAS and SAS).

[CaptRobau]

Why on earth did they not take the opportunity to rename the ASAS/SAS parts sensibly? There's now a mish-mash of 4 versions of control parts.

Yeah, as if ASAS and SAS wasn't confusing enough.

[Danger Will Kerbinson!]

Ok, here is what I want to know.

ALL command units except the seat have SAS(old ASAS function) built in. SOOOO, that is the point of the IAS unit, the one that has the model of the old ASAS? From the description it has the same reaction wheel torque as the reaction wheel unit (old SAS model) but also says includes SAS. WHY does it need to include SAS if all the command pods, probes, remote units etc all have this built in? It looks to me that they have 2 parts that do the same thing, for different costs and weights there and there is still the 2.5m large ASAS part, which unless someone knows otherwise does NOTHING anymore. And why leave a useless part available when it could have been changed to a large reaction wheel unit that would be useful, instead of trying to stack 50 small wheels onto a 2.5m design.

Just a little clarity Squad...just a little, please?

Ill save my dislike on the squishy, useless new SAS system for a different time...like if they patch it and it still doesn't work.

[Kaleb]

Here's my take on it, based on limited testing and reading the part descriptions. First, you can't go necessarily by the name of the part. You have to go by the capability listed in the VAB/SPH.

In 0.20, there were (I think) three types of turning capability:

- Command pod (or probe core) torque, which was user-controllable (ship turned in reaction to QWEASD)

- SAS torque, which was passive only and not user-controllable.

--- Functionally, this had the result of killing rotation.

- ASAS provided no torque, but used a PID controller to control other systems (SAS, RCS, gimbals, wings)

--- Functionally, this had the result of killing rotation *and* locking heading.

From my very limited testing so far, in 0.21, there are two types of turning capability:

- Reaction Wheels: Act like command pod torque (user-controllable) but require electricity (usually at the rate of 6E/min/unit of torque, though there are a few exceptions). NOTE: Parts with reaction wheels contain a "Toggle Torque" option on their right-click menu, so you can turn them off to save power (at the expense of turning power, unless you have something else like RCS to compensate).

- SAS-Equipped: This is meant to be the flight computer/PID-controller; like the original ASAS it provides no inherent torque of its own, but controls other devices. However, functionally, it seems to behave more like the old SAS, in that it kills rotation, but I don't think it restores heading. As a result, it sometimes tends to drift. It's also rather more sluggish (especially with rolls), and it allows manual turning (yay!).

In terms of parts:

- All command pods have *both* RW & SAS

- All probe cores have *only* RW. Thus, probes may have a hard time holding a heading...

- For control parts:

--- The Inline Reaction Wheel has *only* RW. This can be used to supplement your torque.

--- The Inline Advanced Stabilizer has *both* RW & SAS

--- The Large Advanced S.A.S and the Avionics Package have *only* SAS, thus they provide no torque.

Edit:

@DangerWillKerbinson! Note: Probe cores are NOT SAS-equipped. I suppose you could throw the Large ASAS on a lifter or upper-stage that's launching a probe? Otherwise, I'm not sure I see the use either.

Edit 2: What I'd like to see is a probe-sized SAS. KSPX has a probe-sized SAS unit, so it's puzzling they didn't use that. I may see about adapting it once I start reinstalling mods.

Edited July 25, 2013 by Kaleb

[DMagic]

I made a thread on this in the tutorial section.

http://forum.kerbalspaceprogram.com/showthread.php/41941-New-SAS-functionality-and-You%21

Basically it's what Kaleb said above. There is no such thing as ASAS anymore (really change the name of that 2.5m part).

[Danger Will Kerbinson!]

Ok, you are right. I saw reaction wheels on the probe cores and thought I saw SAS equipped as well. But it doesn't really change much, if you are forced to put a .5t 1.25m IAS unit on a .1t .625m probe core you could just throw a 1 man Lander can on there for the same total mass and have the advantage of way more space to stick things to.

[Frederf]

SAS is the rotational stabiliser (think Gyros).

This is exactly what it is not. SAS is math that translates input numbers into output numbers to physical controls. It no more steers your craft than does a pocket calculator.

[Awaras]

So basically, the only reason I would want to use the old small and large ASAS modules (whatever they are called now) is to add SAS functionality to an unmanned probe or a craft piloted from an external chair? Then not adding a probe-sized ASAS ("flight computer") part makes even less sense... :/

[Danger Will Kerbinson!]

So basically, the only reason I would want to use the old small and large ASAS modules (whatever they are called now) is to add SAS functionality to an unmanned probe or a craft piloted from an external chair? Then not adding a probe-sized ASAS ("flight computer") part makes even less sense... :/

This is the gist of whats causing my perplexed look since the update hit.

1. If you don't need SAS(flight computer) functionality on any standard pod then why leave the part in place, it will only be of use to the single unmanned guidance unit that is 1.25m

2. If you DO need the SAS on probes why not a .625m part? After all, the computer part is what is missing which the last time I looked computers weighed a bit less than reaction wheels. By the time you add a .5t IAS unit it has the same mass as a lander can, that sort of defeats the purpose of being a small, light probe.

3. Why is the large ASAS still around? This one has no purpose other than to be used on the 2.5m remote guidance unit.

It feels a lot like the devs got so worked up with the constant "where is .21" moaning that they just hit the panic button and dumped a very half baked update.

[sojourner]

I'm still trying to figure out why they didn't include a 2.5 meter reaction wheel unit. Guess my large unmanned rockets will have to continue using lander cans.

And agreed, they've made a real mess with the naming conventions between pods/control parts.

[Superluminaut]

I'm still trying to figure out why they didn't include a 2.5 meter reaction wheel unit. Guess my large unmanned rockets will have to continue using lander cans.

And agreed, they've made a real mess with the naming conventions between pods/control parts.

Try the probe cores. They have reaction wheels.

[Superluminaut]

This is the gist of whats causing my perplexed look since the update hit.

1. If you don't need SAS(flight computer) functionality on any standard pod then why leave the part in place, it will only be of use to the single unmanned guidance unit that is 1.25m

2. If you DO need the SAS on probes why not a .625m part? After all, the computer part is what is missing which the last time I looked computers weighed a bit less than reaction wheels. By the time you add a .5t IAS unit it has the same mass as a lander can, that sort of defeats the purpose of being a small, light probe.

3. Why is the large ASAS still around? This one has no purpose other than to be used on the 2.5m remote guidance unit.

It feels a lot like the devs got so worked up with the constant "where is .21" moaning that they just hit the panic button and dumped a very half baked update.

The game has always been like this. Many parts we could really need don't exist, yet we have I beams. Also many of the parts have a strange mass when compared to other pats. It's in alpha.

[Danger Will Kerbinson!]

Try the probe cores. They have reaction wheels.

And it takes 5 large remote cores to equal the torque of a 2 man lander can, at the same weight while adding a load of extra parts and their drag for no gain. Not a solution to anything.

I am aware of the state of the game, I didn't just "lol steam sale" this game 2 days ago. This is not about parts nobody uses, its about parts everyone uses, all the time, on everything NOT working for nearly 1/4 of the players.

This whole mess boils down to 2 kinds of people, those who are blessed to not have any control issues with .21 and those who do have them. Unfortunately the first group is behaving like star-bellied sneeches with brain damage.

[Superfluous J]

I just flew to Mun with an OKTO probe core, an avionics package stuck to the top (it was the smallest thing I could find with an SAS), and a single inline reaction wheel. It was a little sluggish before I dropped the mainsail and 2 orange tanks (before reaching Kerbin orbit) but after that it handled like a dream. I never used the RCS thrusters for maneuvering. They were used only as fine-tuning jets to circularize my orbit.

[DMagic]

The avionics package may be your best bet for small probes. I don't like it much though, it looks kind of funny, and I'm not sure if this part is configured differently than the other SAS equipped parts. A scaled down version of the Inline Advanced Stabilizer would be much better for probes. With the way part files work now couldn't they just add another section in the .cfg file with a "RescaleFactor = 0.5" duplicate of the IAS part, with correspondingly updated mass and torque settings?

And I'm thinking that the only reason we still have that stupid 2.5m ASAS module (even the name just seems to add to the confusion) is to allow compatibility with old crafts. If they aren't going to add reaction wheels to that part then they should just get rid of it. It might break a few old craft files, but they already decided to break saves, so I don't think this is a good enough reason to keep it around.