Using moons to slingshot

[fuzzdemon]

Im in an elliptic orbit around Jool with only 500 deltaV of fuel remaining and wanted to try to slingshot off a moon back to Kerbin.

After many failed attempts I decided to time warp and after about 10 orbits of Jool and a few encounters with its moons I got flung into space and into a perfect orbit that took me back to Kerbin. I was able to recreate this lucky slingshot, but I wanted to ask if there is some plugin that will predict this manouver instead of just using luck.

As you can see I only need 174 deltaV to get back to Kerbin. This is such a big saving I obviously want to always use slingshots but cant see how its possible to plan one.

Any info would be appreciated, thanks.

[SRV Ron]

Don't know of any plug ins. But, the Kerbal School of Hard Knocks with quick save will find that magic slingshot to aim you into an aerocapture of Kerbal saving tons of fuel.

[undercoveryankee]

If you're on Windows, Arrowstar's Trajectory Optimization Tool (http://forum.kerbalspaceprogram.com/threads/36476 ) can help you find assist windows. Failing that, just pick a moon that's outside your current Jool periapsis and is on the side of its orbit where you would make an ejection burn, set up the nodes, and see what happens.

[fuzzdemon]

Sounds good ill look into that, thanks guys.

[cantab]

Start by picking a moon to give you the slingshot and setting it as target. Tylo is the most "powerful", I think Laythe can work too and maybe Vall. If your orbit intersects the one of that moon, you should get a marker - if not, adjust your orbit until it does. Then, go about getting an actual encounter in a similar fashion to rendezvousing with a target ship in Kerbin orbit. Once you actually have the encounter and projected onward course, set up a correction that gets you booted appropriately from the system.

[FenrirWolf]

You also want to wait until the moon in question is positioned such that your escape trajectory sends you retrograde relative to the Jool system.

[fuzzdemon]

I didn't think to target the moons i'll try that tip and see where it takes me, thanks guys.

[weeble]

There's definitely the mod that tells you what phase angle/ ejection angle and even how much DV you'll need to do it, it's called Protractor Continued. It tells you everything you're looking for and it works perfectly for .24. The module part it adds looks like a scientific calculator

[fuzzdemon]

Awesome ill check that out thanks man.