Gravity assists in 4 pictures

[mhoram]

While there is a good description about the workings of gravity assists in the thread

http://forum.kerbalspaceprogram.com/threads/54294-Gravity-Assists

I miss somehow a condensed visualization of the process. The wiki page also scratches only the idea.

For this I created this small set of pictures of a gravity assist with the Mun inside Kerbins SOI. Scaling and trajectories are a bit off, but should suffice as a simple visualization.

While trying to keep the information to the bare minimun, I had hoped for much simpler pictures.

This case describes a gravity assist that accelerates the ship.

Simple rule:

Pass the Mun behind it's oribital course to accelerate.

Pass the Mun in front of it's oribital course to decellerate.

Suggestions for improvement welcome.

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[White Owl]

I've never attempted a gravity assist, never yet tried to learn how to set one up. After viewing these pictures, I think I understand the basic idea - obviously some hands-on practice with maneuver nodes is needed to really get it - so I think that's mission accomplished. Nice work.

[FREEFALL1984]

I find gravity assists pretty useful, while some players like to hit launch windows with absolute precision and launch from lko, i dont mind missing out on some of that precision for the extra dv less a little dv spent in correcting my final orbits, although a bad munar assist can get your ship into a lot of trouble so maybe best to practice on unmanned vessels first if you value your kerbals lives lol

[John FX]

http://forum.kerbalspaceprogram.com/threads/80978-Flyby-Finder-for-KSP-V0-40

this is an awesome `flyby finder`

You put in the three planets (or four) for example Kerbin, Eve, Jool and it will work out when you need to launch and how much to burn so that you can go to Jool by doing an Eve flyby and getting a gravity assist. It shows a range of launch windows and you can refine your searches and narrow down the best route to take.

The writer has managed to go from LKO to Jool orbit in about 1050 Dv... (Kerbin, Eve, Kerbin, Jool)