Maneuver node

A maneuver node is a planed velocity change along an orbit. Multiple maneuver nodes can be added which effect the following maneuver nodes. After adding a node it shows the velocity change needed to reach the next new orbit.

Directions

Because any movement in space or air is three dimensional there are 6 possible directions to burn. For each axis there are two opposite directions.

Prograde and retrograde

These vectors are directly changing the speed of the craft. Burning prograde will burning to the craft's velocity vector and raising the altitude of the orbit on the other side. They are colored green like the pro- and retrograde vectors on the navball. This is the most efficient way to change the orbital shape, so whenever possible these vectors should be used.

Normal and anti-normal

The normal vectors are orthogonal to the orbital plane. Any burning normal or anti-normal will change the orbital inclination. On the navball it is between the pro- and retrograde marker on the equatorline.

In most cases these vectors are needed to match the orbital inclination to another celestial body or craft. When the orbit crosses the other object's orbit burning normal or anti-normal is most efficient. To match the orbital inclination a normal burn is needed at the ascending node. At the descending node an anti-normal burn will move the inclination closer to the target's inclination.

Radial in and radial out

The radial in vector is pointing to the orbited body while the radial out points away from the orbited body. When burning radially the orbit will rotate around the craft.