Decoupling without force?

[Kimberly]

I'm having a problem with launching satellites. I can get the launch vehicle into the right orbit just fine, but once I decouple the satellite, it shoots away. This can significantly alter a geosynchronous or sun-synchronous orbit.

I'm using the Clampotron Jr. docking port. Is there a way to edit the docking ports so they don't produce any force when releasing the payload? Or am I just using a bad docking port model?

Edited July 5, 2013 by Kimberly

[stupid_chris]

Nah, it's doing it's job.

What you can do instead, is switch the dockingport for the smallest decoupler and then just put two struts from your satellite to anywhere on the rest of the rocket. That should completely negate the decoupler's force. I'm not sure if it works with dockingports though, that's why I propose to change for the decoupler.

[Sirrobert]

Docking ports should not produce any force when undocking

[Vanamonde]

Docking ports should not produce any force when undocking

I think they do it so that the magnetism doesn't just grab again. I know that a certain distance is also required before the magnetism resets, but I feel that the little push helps avoid colliding with the ship you just left, and that sort of thing. Anyway, in the real world, most (all?) satellites have at least a minor maneuver capability, so why not put RCS on your sats and simply correct for the impetus?

[stupid_chris]

Docking ports should not produce any force when undocking

Maybe not on undocking, but on decoupling yes. And there is a difference. If two dockingports are connected together, the game considers it as a dock. If a any other part is attached to the port, like the satellite's bottom piece, it's considered a normal connection, and the dockingport will add as a decoupler, and it has a very low decoupling force, somewhat around 5 I think, but it's enough to shoot a small satellite forward.

[Kimberly]

Maybe not on undocking, but on decoupling yes. And there is a difference. If two dockingports are connected together, the game considers it as a dock. If a any other part is attached to the port, like the satellite's bottom piece, it's considered a normal connection, and the dockingport will add as a decoupler, and it has a very low decoupling force, somewhat around 5 I think, but it's enough to shoot a small satellite forward.

Ah, so I can fix this by adding a docking port to the satellite? Thanks.

[stupid_chris]

Ah, so I can fix this by adding a docking port to the satellite? Thanks.

Well that adds extra weight and might look weird, that's why I think decoupler and struts are the go, but that's up to you

[joppiesaus]

you can do two decouplers, both the other direction, the force will neutrialize.

[sgt_flyer]

struts cancel out decoupler force on standard decouplers - maybe it works too for docking ports (unless you have something partially clipped inside the docking port) (and no, two docking ports connected together in the vab will still use the 'decouple' command the first time. - and the docking ports still generate a small decoupling force, even when simply undocking)

[pizzaoverhead]

If you want to make a zero-force decoupler, you can make a copy of an existing decoupler and set its ejectionForce to 0.

[Sirrobert]

Maybe not on undocking, but on decoupling yes. And there is a difference. If two dockingports are connected together, the game considers it as a dock. If a any other part is attached to the port, like the satellite's bottom piece, it's considered a normal connection, and the dockingport will add as a decoupler, and it has a very low decoupling force, somewhat around 5 I think, but it's enough to shoot a small satellite forward.

I see, thanks

Anyway for the manouvering of the satalite, I always put 1 tiny fuel tank with with the ant engine on my satalites, and connect the ant engine to the docking port.

Hardly any weight, and gives a suprising amount of delta V (cause the thing is so light)

[nemesis666first]

Any idea how change Ejection force AFTER liftoff plz ? Any mod ?

[Kourou]

Savefile editing. Just open your save in the Game Directory(it's a simple, not too hard to understand txt), search for your vessel (Ctrl+F helps), search for the decoupler part, and change the respective value. If it is a docking port, then it's impossible (without a probably not existing mod), they have set ejection force values.

[FancyMouse]

I tend to attach Ant engine with small amount of fuel (which gives a lot of dV, btw) to my satellites just so that they can correct orbit themselves, and I don't need to worry about problems like this. It's also very helpful for batching multiple satellites into a single launch, as I can just launch once, find some orbit for my "mothership", then detach them and let satellites adjust to the target orbit (may cost several hundreds dV but Ant should give >1km/s dV if your satellite is not huge).

[Sharpy]

Note Separators by default don't exert any force.

[Reactordrone]

Note Separators by default don't exert any force.

This isn't correct. Separators exert more force than decouplers.

Nah, it's doing it's job.

What you can do instead, is switch the dockingport for the smallest decoupler and then just put two struts from your satellite to anywhere on the rest of the rocket. That should completely negate the decoupler's force. I'm not sure if it works with dockingports though, that's why I propose to change for the decoupler.

This isn't correct. Struts reduce a decoupler's force, they don't completely negate it. The more struts, the less force exerted.

you can do two decouplers, both the other direction, the force will neutrialize.

No, it won't.

[Windspren]

Get TweakableEverything and you can change the decoupling force.