Overview
A very simple guide to catch the sphere of influence of your target space rock to orbit or land on it. Mainly shows how to catch Mun or Minmus, but might be useful on other planets too.
0. Starting
This guide assumes that you:
1. Know how to get into Kerbin orbit
2. Have enough Delta v for your mission.
3. Know how to the use maneuver node (seriously, there is nothing hard about it).
4. Know how to target a moon, planet, etc.
If you didn’t already, please, play the ingame tutorials! They are very extremely useful for a new player, along with all the other guides the community has created.
This guide is mainly for getting onto the Mun or Minmus, but will probably help you on your journey to other planets, moons, meteors, and comets.
Be sure to check out other maneuvering and orbiting guides for more advanced and a lot more efficient maneuvering!
1. Orbit around Kerbin
This should be the most simple and straightforward part. Although it is more efficient to gun straight at the moons from the start, making a stable orbit in Low Kerbin Orbit gives you all the time you need for planning, and lets you fly to a moon regardless of where it is in it’s orbit.
2. Lining up your orbit
[link]
Set your target moon as a target, make a maneuver mode at either AN or DN and burn Normal/Antinormal until your AN or DN is -0.1* or 0.1*, although 0* is more preferable if you can get to it.
If you need to burn Normal/Antinormal a lot, like to catch a meteor in a polar orbit, you will need to burn in both Normal/Antinormal and retrograde, since Normal/Antinormal direction will slowly change as you burn in it’s direction.
3. Intercepting / start of orbit injection
[link]
Create a maneuver node. Increase in prograde until your apoapsis touches the orbit of your target. Drag around the maneuver node around your orbit until you can have an encounter.
If you overshot or undershot and don’t have an encounter, burn a bit prograde or retrograde until it works or get the 2 light blue markers with a line in the middle as close as possible until you get an encounter.
[link]4. Making stable orbit
[link]Time skip until you reach the encounter. The line showing your path should be a lot different now. All you need to do now is burn retrograde a few times until you have a stable orbit.
From here you can do anything you wanted to do with your target, like landing, or setting up relay satellite orbit.
You can also skip this if you just wanted a flyby, and let the target slingshot you back out of it’s sphere of influence.
(General rule of slingshots: if you leave soi in the direction the target is orbiting, it will make your resulting orbit bigger. Leaving soi in opposite direction of the target’s orbit will make your resulting orbit smaller)