Question Attitude Locking

[Mandella]

Has anyone devised a way to lock a station's axis to be permanently sun facing without having to use thrusters or a running MFD? (As in to simulate using gyroscopes for stability, for example.)

Thanks!

 

[Wishbone]

How tough is the station? You can always try spin-stabilization , but please bear in mind that even with CMGs, in real life one has to periodically dump momentum by other means (RCS, magnetorquers, whatever). The CMG for the ISS ([ame="http://www.orbithangar.com/searchid.php?ID=4946"]CMGv1.0[/ame]) is one add-on that comes to mind.

 

[Mandella]

The CMG for the ISS (CMGv1.0) is one add-on that comes to mind.

That addon is definitely on the right track -- I'll try it tonight and see if it works.

Basically, I am trying to lock large habitats such as the O'Neil cylinder and the Stanford torus into their proper attitudes. These things are huge and have no internal means of attitude adjustment, and frankly I wouldn't mind a "cheat" to keep them aligned properly over long periods of time acceleration and such.

Right now I am just cludging it by bringing up the Scenario Editor and manually aligning them per scenario. That works, but I was wondering if there was a more elegant solution out there...

 

[Wishbone]

As an alternative to having MFDs open, you could take the cheating code from my Precession MFD source (the one that makes use of quaternion Slerp), and either port it to Lua or insert into a non-MFD plugin. There is the opportunity to schedule attitude changes in advance.

 

[Mandella]

you could take the cheating code from my Precession MFD source

I am embarrassed to say that my ability to code is limited to basic cutting and pasting of scenario and config files. I know what Lua script is, but I fear I have no idea how to read it.

But I promise if you put something together for me like this, I would name a station after you in my solar system.

 

[Wishbone]

Hehe, modesty is my main vice, so no stations, please. Back to attitude control:

Alas! Due to teaching and work obligations time for development is quite limited, but would like to hear from you the exact requirements - do you need Sun-tracking? I can put into the Precession MFD cheat autopilot. Unfortunately, cannot migrate the existing code into a MFD-less behind-the-curtain plugin.

 

[Mandella]

Sun tracking, with the ability to choose the axis of course. Fortunately the whole station (in both cases) needs to be aligned, and not just the solar panels, so I would think that would make it easier (no animations to worry about).

And thanks again! I've downloaded the current version of your precession MFD, but haven't had time to play with it (solar sails are scheduled for next week!), but from the readme it looks to be a powerful tool indeed.

 

[Ark]

I'd like to see an MFD that can lock any vessel into a specific orientation so you can perform long burns with unbalanced vessels without attitude drift.

 

[Xyon]

[ame="http://www.orbithangar.com/searchid.php?ID=3165"]Attitude MFD V3.2[/ame] does just that, unless my memory fails me. It can also hold your attitude relative to an object, but it can just freeze your attitude to prevent rotation (to tolerances, iirc).

 

[Ark]

Attitude MFD tries to use the RCS thrusters to hold attitude, and just isn't able to keep an unbalanced ship from drifting around. What needs to happen is an MFD that completely prevents any kind of rotation.

 

[jedidia]

I'd like to see an MFD that can lock any vessel into a specific orientation so you can perform long burns with unbalanced vessels without attitude drift.

IEATMFD has such an attitude lock. And the attitude hold of the orbiter navigator does quite a good job at it too, without cheating.

 

[Ark]

IEATMFD's attitude lock appears to be exactly what I need. However, how do I get it to lock on to the attitude that I want? I line the ship up on the IMFD burn target, hit the attitude lock button, and the ship jumps to an entirely different attitude. Read through the documentation and all is says is that it holds attitude relative to prograde.

 

[jedidia]

You probably have the wrong reference selected. It holds attitude relative to the prograde direction of the selected reference, which results in havoc if IEATMFD reference and the reference of your hud aren't the same.

 

[Ark]

I must be doing something wrong. I set the reference to Earth, aim the ship at the IMFD indicator, hit the attitude lock button, and it snaps me to an entirely different attitude. Repeatedly pressing the attitude lock button eventually snaps it to my orbit's prograde.

 

[jedidia]

There's not much you can do wrong, really. All I used to do is set the IEATMFD reference to the same my hud was, align the ship and activate the attitude hold, so pretty much what you are doing too. Yet I never experienced the trouble you are expieriencing. Very odd...

 

[Ark]

Unbelievable. Apparently the problem only happens with the Long Shot, which is the only ship I need to compensate for unbalancing problems with.

 

[jedidia]

The long shot seems to have some pretty weird issues with a lot of things, I have no idea why...

 

[jinglesassy]

Couldn't you make a invisible mesh with a docking port and dock it to the longshot and use the invisible ship to keep the attitude?

 

[Ark]

I think I'll just do that with one of the XRs already docked to it. Isn't there an addon that allows you to remotely activate another ship's thrust?

EDIT: Never mind, CTD when I try it. :beathead: