Duna to Kerbin

[figmentius]

I'm having no luck on my return to Kerbin from Duna. Getting to Duna using Kosmo-Not's guide is no problem. However, I have yet to successfully return. My angle to prograde I am using is 301 (using a heading of 270) and my phase angle is -75. Maybe I am just misreading Kosmo-Not's guide, since the angle listed in 121 degrees to retrograde (using a heading of 270).

Any advice?

[figmentius]

Also, if my heading was 90 degrees instead of 270, what would be my ejection angle be then?

[Wayfare]

A heading of 270 is wrong in (almost) any scenario - all it does is make it harder to achieve orbit because you have to fight against the starting body's rotation. I'm not in a position to check the angles for you right now as I'd have to launch a craft to Duna first

I really recommend the Protractor Rendezvous Plugin - it will do all the nasty math for you. Plus it has a nifty "closest approach" line on the map screen that will let you fine-tune your trajectory even if you don't have an encounter yet.

KSP is asking us to shoot at fruit flies with lawndarts. I say, fight the system!

[figmentius]

Thanks! I'll give that plugin a try.

[nhnifong]

Try a phase angle of more like -73° (let Kerbin get a little farther ahead) and then on your mid course correction burn, "scan" Kerbin's orbit by lowering your peri. At a certain point, the amount of catchup you do on this short bit under kerbin's orbit will match the amount that you are behind it. Note, you will hit kerbin with more velocity this way.