[video] Understanding gravity assists

[allmhuran]

[rottielover]

Excellent stuff! Thank you very much. As I mentioned in the other thread, I'm a visual learner and this helped me understand Ll that text! Thank you.

[pa1983]

Yes very good video. I have been trying to do gravity assists with well varied results and some how its pretty obvious when you show it, after all I use the same basic techniques to get to Duna and Laythe and back with my spaceplanes but actually understanding how to exploit it to its maximum still eluded me a bit. This helped a lot in explaining how to think about gravity assist and how to plan for it.

Also I would love to know what mod that was to change the Conics mode. Seem very useful.

[allmhuran]

It's called improved manoeuvre nodes

http://kerbalspaceprogram.com/maneuver-node-improvement/

Has a few minor bugs but of course the stock nodes have a few minor bugs too.

[djnattyd]

I just learned something! Great stuff.

[quantumpion]

My question is how do you set up your orbit intercept in order for your ejection angle to be in the right direction in order to both benefit from the maximum gravity assist possible and send you in the correct direction to intercept your desired target.

I've been trying to do a Juno-style mission where you launch from Kerbin into elliptical orbit towards Jool, do a orbital correction at apoapsis to target Kerbin, then get a gravity boost from Kerbin to get the rest of the way to Jool. But I haven't had much success getting the timing right.

[allmhuran]

Setting up a mission where you start from object 1, get a gravity assist from object 2, and immediately intercept object 3 at your new apoapsis is entirely dependent on having the planets align properly, there's nothing you can do to change that. So you've got two options, either...

1) Use a launch window planner tool to figure out what date you would need to launch in order to get a perfect assist to intercept, assuming you also do all your burns perfectly, or

2) Just get your gravity assist to raise your apoapsis to the altitude of object 3, and then simply loop around in elliptical solar orbit until you have a close approach at apoapsis, then make small correction burns to get your intercept.

99% of the time I go with option 2.