The S.A.S.

[Johno]

Okay, so I understand the basics - the SAS module stabilises the craft when you toggle it using the 'T' key. I know that it works. But I want to know more than that - WHAT exactly does it do?

I have worked out that when you are in orbit, SAS keeps you pointing whichever way you're going, and that you have to switch it off to change your heading. But details.

i.e. Is it a rocket pack? A gyroscope? What? Does its position in the stack matter, and if so, what is best?

Thanks in advance.

[Darrknox]

I believe it stabilizes anything below itself. How it actually works, would be up to the person.

[Capt'n Skunky]

The SAS unit attempts to keep the craft in it's current attitude, i.e. it keeps the navball from moving.

It's only so strong and can be overcome by stronger forces. If your rocket still drifts when SAS is active you may need additional SAS units. At some point, the weight of adding more SAS units will be undesirable. At that point you need to help maintain attitude manually.

When you activate the SAS on the pad your rocket is pointing straight up so it will attempt to keep your rocket heading that way. When you are ready to transition to horizontal flight or you just need to make a an attitude change, you can deactivate the SAS, manually adjust your attitude to where you want it, then reactive the SAS to hold your new attitude.

Cheers!

Skunky

[Moach]

HarvesteR told me it was supposedly a flywheel setup... he also added that in future versions, whenever electrical power makes it into the simulation, the SAS should draw it's share out of it

then there would be other options, such as RCS modules which require propellant in order to maneuver (but are more flexible, in terms of flight control)

i informed him that the current way the SAS hold attitude is somewhat strange, for it functions as an attitude-hold deal, and that it should reset the target direction when input is given by the pilot... so it'd act more like a real stability augmentation system then

probably in a few versions from now, this will be fixed :

[McLuv]

i informed him that the current way the SAS hold attitude is somewhat strange, for it functions as an attitude-hold deal, and that it should reset the target direction when input is given by the pilot... so it'd act more like a real stability augmentation system then

probably in a few versions from now, this will be fixed :

I was thinking it was wierd, because if it was in a gyroscopic setup, you should be able to turn the flywheel one way to turn the craft in the opposite direction.

Perhaps also turning on and off the SAS should have a 'warm up/down' time as the hypothetical disk has to be accelerated and deccelerated.

[Rocket Surgeon]

...Perhaps also turning on and off the SAS should have a 'warm up/down' time as the hypothetical disk has to be accelerated and deccelerated.

Solid-state accelerometers! Flywheels are SO 19th century. Nevermind that gyroscopes in modern flight instruments only take a few seconds to spin up and stabilise.

[Xivios]

Yes but those instruments are exactly that - instruments. They display info but aren't designed to actually impart any force.

The flywheel in the SAS actively forces the vessel around, and only a heavy mass spun at high RPM can do that. That said, I like to think that it works within it's own personal vacuum chamber, on magnetic bearings and is spun up before flight. On and Off only lock and unlock the gymbals of the massive and very high RPM wheel. Of course, the gymbal is also hydraulically forced and computer controlled, which is why it's a fully active stability system.

[ijuin]

If it's gyroscopic, then it should precess when disturbed by the launch forces or by a player trying to turn the rocket. However, the current SAS module simply produces oscillation instead of precession.

[ryacko]

The SAS unit attempts to keep the craft in it's current attitude, i.e. it keeps the navball from moving.

It's only so strong and can be overcome by stronger forces. If your rocket still drifts when SAS is active you may need additional SAS units. At some point, the weight of adding more SAS units will be undesirable. At that point you need to help maintain attitude manually.

When you activate the SAS on the pad your rocket is pointing straight up so it will attempt to keep your rocket heading that way. When you are ready to transition to horizontal flight or you just need to make a an attitude change, you can deactivate the SAS, manually adjust your attitude to where you want it, then reactive the SAS to hold your new attitude.

Cheers!

Skunky

Don't you mean keeps the craft at it's current angle?

[Tim_Barrett]

SAS modules are as good as nothing if they aren't on.

I cannot tell you how many times my friends have forgot about taht