A few newbie questions

[Charlie32]

Been playing the game for a few days and I'm loving it, despite only just getting the hang of space travel, but have a few questions about the game.

Firstly, particularly with big ambitious rockets, ill put them on the launch pad and switch my advanced sas on (no standard sas on board) and it'll go crazy with whatever winglets I have trying to keep it 'balanced' when I have it held by the launch supports, and continues this as the rocket ascends; is this a) wasting fuel, and a fault of sas? I accept that my rockets are probably for the most part unstable, but if I turn sas off it doesn't require an awful lot of effort on my part to keep it straight!

On the topic of sas, I read (while searching for this issue) and the difference between advanced and normal sas, would that be a possible solution?

I've been experimenting with some ion spacecrafts, using other rockets to get it up there and then breaking off, but I've got two issues there, I can never get much electricity input, no matter how many panels I cover the wings with. And then I struggle to design it, I know I need to keep the weight low, but what can I make the body out of?

Any help is much appreciated!

[Crown]

[...]is this a) wasting fuel, and a fault of sas? I accept that my rockets are probably for the most part unstable, but if I turn sas off it doesn't require an awful lot of effort on my part to keep it straight!

It sounds like you are enabling RCS too.

A combination of RCS and ASAS enabled works only with a small and very stiff vessel. Basically just the command pod and some engines+fuel for navigation. I usually enable RCS to get the space craft oriented, disable RCS and enable ASAS to hold it's position. With almost any vessel I made RCS+ASAS freaks out and wobbles like crazy.

During ascent I only have the ASAS enabled because the Mainsail engine's gimbal is enough to steer and keep the rocket on course.

To minimise wobbling during ascent I quite always build a combination of small Hardpoints, octagonal struts, attach it with symmetry tool to the rocket and attach some strut connectors to the rocket to make some triangles.

Looks silly but it keeps the rocket more stable.

Switching from ASAS to SAS would not solve the problem, I think.

SAS has some kind of gyroscope build in to keep the rocket straight. ASAS uses other parts like wings, RCS, etc.

And, Yes. The way ASAS reacts to your rocket is normal and an inevitable issue. Solving this problem includes a packet of maths and the ability of the game to change the part files continuously. And perform a ton of equations (besides calculating the game data).

[...]but what can I make the body out of?

You can try using a Structural Fuselages. This way maybe you can get more of these huge solar panel attached. The ion engine doesn't produce much thrust. I use it only an satellites to correct their orbits.

[Charlie32]

I don't put any RCS on my ships, and dont enable it, so I don't see ho that could be the issue, but I will try adding struts in the way you've suggested, so hopefully that'll help.

I know the limitations of the ion engine, it's more of a kinda project for me, I just want to try and make a viable small space craft that doesn't require any fuel. I'd come to to conclusion that structural fuselages were the best way forward, but still can never seem to get enough energy being produced by my ship to power the two thrusters I have, I know going down to one is an option, but then like you said there would be even less thrust.. But I shall continue to play with it

[Vanamonde]

The motion of the winglets doesn't waste any fuel, except for the tiny amount of additional drag they add to the ship. I don't believe the game's aerodynamics model is sophisticated enough to take that changing airflow into account, and the increase in drag due to canard AOA would be tiny. Replacing the ASAS with SAS would stop the canard flutter, but only because the canards would be inert then and acting like static fins, not contributing much to the stability of your craft. As for your ion ship, what body parts does it need? Perhaps just build the working parts off of structural sparts extending from the probe core?

[Capt'n Skunky]

Happy Launching!

Arrr!

Capt'n Skunky

KSP Community Manager

[Charlie32]

The motion of the winglets doesn't waste any fuel, except for the tiny amount of additional drag they add to the ship. I don't believe the game's aerodynamics model is sophisticated enough to take that changing airflow into account, and the increase in drag due to canard AOA would be tiny. Replacing the ASAS with SAS would stop the canard flutter, but only because the canards would be inert then and acting like static fins, not contributing much to the stability of your craft. As for your ion ship, what body parts does it need? Perhaps just build the working parts off of structural sparts extending from the probe core?

Okay that clears up a lot, so the winglets going crazy isnt a huge problem, which is kind of a relief.

Well see there isn't really any end goal with it, I just wanted to play around with the physics a little bit, but as has already been pointed out, they're too slow to be of much use for anything, so I may give up on that one.