Velocity change required, in meters per second.Adjustments to an axis can be made also by hovering over one of its nodes and scrolling the mouse wheel.Īfter adding a maneuver node three new values will appear next to the navball: The further the symbol is pushed or pulled, the more rapidly the adjustment will be made. Pulling a symbol away from the center of the node increases the speed change along the selected axis, and pushing a symbol toward the center of the node is equivalent to pulling the symbol on the opposite side. Each symbol can be clicked and dragged to adjust the amount of velocity change desired on each axis. Upon selecting a maneuver node six symbols will appear, each corresponding to the vectors above. Rotating the orbital plane opposite with the orbiting direction using a radial-out burn. The maximum change in angle is always less than 90° beyond this point the orbit would pass through the center of mass of the orbited body and the ship would traverse a slow spiral in towards the orbited body. Radial burns are usually not an efficient way of adjusting one's path - it is generally more effective to use prograde and retrograde burns. Performing a radial burn will rotate the orbit around the craft like spinning a hula hoop with a stick. The radial (or radial-in) vector points inside the orbit, towards the focus of the orbit, while the anti-radial (or radial-out) vector points outside the orbit, away from the body. These vectors are parallel to the orbital plane, and perpendicular to the prograde vector.

When the relative inclination at the nodes will reach 0° and they will start to move rapidly toward each other's positions. To match the orbital inclination, either perform an anti-normal burn at the ascending node or a normal burn at the descending node. These vectors are generally used to match the orbital inclination of another celestial body or craft, and the only time this is possible is when the current craft's orbit intersects the orbital plane of the target - at the ascending and descending nodes. On the navball the normal and anti-normal vectors are located on the equator line directly between the prograde and retrograde markers. Burning normal or anti-normal will change the orbital inclination. The normal vectors are perpendicular to the orbital plane. When the craft is powerful enough it is possible to switch the orbital inclination by 180° when burning retrograde to cancel out all orbital velocity and then build it back up, which is faster and more efficient than using the normal vectors. This is the most efficient way to change the orbital shape (specifically the most common case, raising or lowering apsides) so whenever possible these vectors should be used. To raise a craft from a lower orbit into a higher orbit using a Hohmann transfer two prograde burns are executed while lowering an orbit two retrograde burns are used. Burning prograde will increase velocity, raising the altitude of the orbit on the other side, while burning retrograde will decrease velocity and reduce the orbit altitude on the other side. These vectors directly change the speed of the craft. eastward), normal will be north, prograde will be east, and radial will be down.

For a prograde equatorial orbit around Kerbin (following Kerbin's rotation, i.e. If you hold the first three fingers of your right hand at right angles to each other in the most natural way, the index finger points forwards representing prograde, the middle finger points towards the orbital focus representing the radial, and the thumb points 'upwards' represents the normal. The relationship between these three orbital vectors - prograde, radial and normal - is defined by the right hand rule. All six of these directions are marked on the navball, using the symbols above. Because there are three dimensions of movement in space (or air), there are three basic axes on which to burn, with two directions per axis thus, all maneuvers can be described as a combination of movement in three separate directions.

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