Parachute Build Aid

[Alshain]

Here is a mod idea for any developer that wants to attempt it. I was trying to build a really early stage SSTO that would land on it's broad side (cause I don't have legs) and found it incredibly difficult to balance the parachutes. We need a mod that would show an Arrow off the CoM (or DCoM) pointing to where "down" would be when parachutes are fully deployed. So in my case, a tall cylindrical rocket with 4 radial parachutes. If the line were perpendicular to the rocket, that means I would have it correct and the craft should land evenly on it's side.

Alternatively you could show rotational direction based on the chutes as well and when the rotation disappeared (similar to RCS Build Aid) it would be even.

This would help bringing odd sized/massed craft back to Kerbin while landing in one piece.

[FleshJeb]

rotational direction

Torque.

This is an excellent idea.

[Alshain]

Torque.

This is an excellent idea.

Yeah that My words aren't working tonight.

[SpaceplaneAddict]

If only I knew how to mod...

[Superfluous J]

I agree this would be really cool. Like RCS Build Aid I'd like a dry/wet option too, so I can see how it'll dangle full of fuel (for my Duna landings) and empty (for coming home).

Also a m/s for each planet would be nice, too.

[Alshain]

The real trick here is figuring out how to display it when it could be two directions. In the example of my cylindrical rocket, you could assume the roll of the craft would orient itself so the parachutes are at the sides but it could still come over on either side.

I know what I want, but the idea needs some fleshing out. Maybe more of the community could help do that.

Perhaps something kinda/sorta like this. This mock up shows that the craft would come down angled with the nose slightly up and the engine down (there are 4 parachutes there).

This mock up would indicate perfect balance.

Edited September 26, 2015 by Alshain

[Kerbas_ad_astra]

Actually, this could be even simpler than RCS Build Aid -- since parachutes always apply force in the same direction (i.e. against the current velocity vector), all it would need to add is a "center of support", the average position of all parachute parts weighted by area. Since the CG will dangle below the "CoS" when the chutes are open, the designer then has a direct visualization of how the system will behave.

[starchitect]

I've just spent an evening tweaking a recoverable first stage design over and over trying to get the parachute balance just right. Googling my problem brought me to this thread - seconding my support for someone with modding talents to make this little app!

Kerbas, I think you are right with the Centre of Support indicator idea - all the mod would need to do is show another coloured sphere, similar to the RCS Build Aid dry centre of mass indicator. If you wanted to be fancy, you could draw an arrow from the CoM to the CoS to indicate clearly which direction would be 'up' as the craft descends.