Part De-orbiting

[swamismurf]

Now that persistence will be implemented in the new version, I\'m wondering what sort of part modifications would be needed for automated deorbit?

0. Would custom part scripts still operate after disconnection if the 'operates after disconnection' flag is active?

1. Will scripts be able to tell KSP 'Don\'t unload me, I\'m not done yet!'? This would then allow the parts to remain active and perform their actions even if they are far away from the current craft.

1. Retro-thrust module: Can liquid engines now fire in reverse? Are solid engines the only ones that can be made into retros?

2. SAS (the moment wheel kind) does not appear to function, even with ActivatesEvenIfDisconnected = True. Or am I on crack? Do some experiments!

3. Same with ASAS and RCS.

Why do we need SAS? If the rocket part we want to recover is tumbling, there is a small chance that when we fire the de-orbit stage it will be pointing pro-grade, boosting it to a higher orbit, instead of to a lower one! Therefore, we need to force the part to an orientation suitable for the retros.

[Guest TonyZ]

*grabs popcorn and takes a seat*

[Tiberion]

0: They should, since the script has access to all part parameters.

1a: Doubtful, things that are far away have to be on rails, because they farther from the scene origin a part is, the more imprecise actions are, so you wouldn\'t want a remote part running calculations.

1b: They have the same thrustvector parameter (which allows you to change the direction of thrust), and even if they didn\'t, a custom engine module could be created to allow it.

2: You are correct

3: Still correct - probably something can be done with custom parts, we\'ll have to see how things work a bit more to be sure.

Re: SAS, even it really isn\'t up to the task of an extended deorbit burn, since it maintains an ABSOLUTE heading and not one relative to an orbit (it won\'t turn you to maintain alignment with your TVV marker) we\'ll need a true autopilot module for that

[Samonite]

This should be quite easy.

1. Make a new SAS model (or reuse the default)

2. Make a script for the model that will set the target of the SAS to the inverse velocity vector when the SAS module is activated.

3. When the direction vector is within A% of the inverse velocity vector, the SAS module activates all engines below at B% throttle.

4. The throttle is set to 0% when the periapsis of the vessel is below C.

(more steps could be added to activate parachutes and so on...)

Edit:

...Doubtful, things that are far away have to be on rails..

Forgot about the rail system. It might be a huge problem.. even for scripts in general.

[engelnicht]

What is the editor phrasing for \'operates after disconnecting\', anyways?

[Tiberion]

ActivatesEvenIfDisconnected = True

Doesn\'t work on all parts, and I actually am not sure which ones it does work on; Parachutes, decouplers, solid boosters for sure, maybe liquid engines too. Not winglets or RCS blocks which require input to activate.

[engelnicht]

You rock!

[Tiberion]

You rock!

Thanks; Be sure to read the reply in the other thread, it had more details (in fact I\'ll edit those in here, too.)

[Joshua21B]

I would take a look at the Mech Jeb plugin. I\'ve seen it used to control a cart that separates from the CM.

[IrritableGourmet]

Pardon me for being new, but if you set a retro rocket as having a low thrust, long burn time, zero heat dissipation, and low maxTemp, couldn\'t you use it to decouple stages, wait until clear, and then explode?