How to Enter Kerbol SOI and Immediately Re-enter Kerbin's SOI???

[Apollo13]

To gain 6 Experience points, the Kerbal must briefly enter Kerbols/Solar SOI. I would like to do that, then immediately re-enter Kerbin's SOI to orbit, land, and recover. How do I do that?

I can easily enter Kerbol's SOI. However, if I then retro-fire engines, I plunge towards Kerbol, which is the expected behavior. This thread Experience Level-up mentions entering, then immediately leaving Kerbol's SOI.

[Endersmens]

My (inefficient) advice is to get in a very high orbit around kerbin, and then just barely push out of kerbins SOI in a prograde (to kerbins orbit) and slightly outwards (radial) trajectory. This will take you a bit above kerbins orbit, and kerbin should catch up to you if you do it right. (if you need more detail let me know I'll try a better explanation.)

[Apollo13]

@Endersmens: Thanks, I'll give that a try. How high of a Kerbin orbit do you fly?

I've flown hundreds of missions, but never had to do something like this.

Edited May 13, 2015 by Apollo13

[Endersmens]

My worries wouldn't be about getting back in Kerbins SOI, but getting back in Kerbins atmosphere from out of SOI.....eek.

[Apollo13]

Your idea worked like a charm. 6 XP for 7 crew members. Thanks and a forum Rep point to ya.

[Endersmens]

You're welcome!

I'm not sure if the high orbit around kerbin was necessary, it was just a safety precaution. Glad it worked!

[FlyingPete]

I've done this before (hop out of Kerbin's SOI, do science, return, profit). The method I used was to just burn from LKO until I got an escape trajectory. Once you're in Kerbol orbit, fire directly at Kerbin and you should be recaptured. This works as long as you're barely escaping Kerbin.

[Hannu]

Easiest way to find directions is to make burn so that ship escapes to Kerbin's orbital direction. Put maneuver node so that you just escape. It should be about 900 m/s from low orbit. Then adjust time so that interplanetary apoapsis is as high as possible (avoid moons). Apoapsis is typically about halfway between Kerbin and Duna. Execute the burn and wait until you escape from Kerbin's SOI. Then do the science stuff. After that create a maneuver node with about 200 m/s retrograde dv. Adjust dv so that you get an an encounter after couple of hours. Execute burn, dodge attacking Mün, adjust periapsis and land back to planet.

That strange 200 m/s is error from patched conic gravity model of KSP. Escape velocity of Kerbin at the edge of SOI should be about that but game does not take Kerbin's gravity into account at large distances. So you get freely such an energy every time you leave the planet.

[Apollo13]

Thanks for the ideas, guys. I'll be making this trip a few more times to earn XP for my 30 Kerbals.