Manuever nodes

[7499275]

Hey guys, I'm not one to often come here and ask for help but... I need help with manuever nodes. I have always relied on mechjeb to help me do interplanetary transfers well I am not going to use mechjeb on this new update at all.

So really I could use a detailed explanation as to doing an entire planet intercept. I can get to the mun and minmus but that is without nodes. thanks guys!

[Rusty6899]

First of all it helps to have a rough idea of where you need to start your burn, so for example with Duna you want Duna to be 30-40 degrees ahead of Kerbin. Make sure you set your target.

As Duna is further from the Kerbol than Kerbin, you want to click on the point of your orbit where Kerbin is directly infront of Kerbol (if that makes any sense). This creates a manoeuvre node, which is basically a point with 6 normal directions. For most bodies, you will only really need to worry about the prograde direction, as most bodies lie on roughly the same plane. Drag the prograde symbol away from the centre and the dashed line will show you the orbit corresponding to that level of burn (the delta-V requirement is shown to the right of the Navball).

When your manoeuvre line intersects with the orbit of your target, two pentagonal symbols will show up, one on each orbital path. The pentagon on your ship's orbit will show the closest distance that your ship will come to the target. This needs to be within the target's SOI to get an encounter. Burn more slowly as you near the intersect to ensure an encounter.

When this is done, you will need to replicate the manoeuvre with your ship. The manoeuvre node will show the time until you need to perform the manoeuvre and blue crosshairs will appear on your Navball to show you the required direction of burn. As you burn, the delta-V requirement to the right of the Navball will decrease and a predicted burn time will be displayed underneath.

When the distance between the target object and your trajectory are small, you can use trial and error by burning in different directions and seeing the effect it has on closest approach.

When you encounter a planet, burn retrograde at the periapsis and you'll eventually reach orbit.

For reaching bodies with orbits on a vastly different plane, such as Eeloo, you need to use the pink symbols on your manoeuvre node to change your orbital inclination.

That's all I have to say about that.

[MrChumley]

For interplanetary transfers you need to know about 2 things:

Phase angle: this is the position of your current planet vs the planet you are trying to get to. (see chart). (this requires waiting long periods of time ex. 130 days)

Position in your current orbit around the planet: (requires less time) After your planetary phase angles are alined you need to know where in your orbit to start the burn. This involves setting up a maneuver node to burn prograde (with respect to your craft)... if the planet you are transfering to is closer to the sun than you need to align your exit trajectory retrograde in respect to your current planets orbit.

Heres a chart I use all the time:

At the bottom is a chart that shows minimum delta V required to do different transfers.

[7499275]

Thanks guys! Makes a lot more sense now then what it did... Still 2 questions. If they are not on the same plane because I don't always have a perfect launch how do I change my inclination to match the target planets.

2nd how do I tell the angle of the target planet from my location? Good guess work?

[Procyon]

set your destination as your target, click on it and the make target dialog comes up. you should get 2 green icons that look like the ap and pe icons. they will say AN and DN, these are your ascending and descending nodes, it should give you a +\- deg reading, make a maneuver node on one and adjust the purple arrows up or down, make burn..

[Rusty6899]

I just use guess work for the angles. I don't use any mods so I'm not sure if there's any way to calculate them. I just make sure I don't overshoot them when I'm timewarping them into place. Then I'll check how far away I am with a manoeuvre and correct it.

For changing the inclination, assuming you are attempting to match your orbit with the plane of another object/planet, you need to set the object/planet as a target. Then you will see two lines joining the orbits of your ship and the target. These are the ascending and descending nodes and are the points where the planes of the orbits of the two objects intersect.

When you cross the ascending node, you need to burn 90 degrees to your direction of travel (if you go on the orbit map and set a manoeuvre node it will be the directions that the pink symbols indicate), so if you are in a Kerbin orbit perfectly west-east, you need to burn north to increase your inclination. Alternatively you could burn south at the descending node.

The other option to encounter objects with inclined orbits is to set up to encounter them at either the ascending or descending node. This is easy enough with Minmus, but I imagine it would take a long time to do with Eeloo as it would rely on Eeloo being in one of two specific points in its orbit and the timewarp is painfully slow for getting to the distant planets.