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# "Set Orbit" for perfect relays?

## Question

I swear the "Set Orbit" function has changed in the past few updates. Been having some trouble with it trying to set polar satellites at equal intervals from each other. EQ sats I can seem to manage.

SMA

Eccentricity

Inclination

MNA

OBT

LAN

Arg Pe ( this is new to me )

I set my SMA for the orbital period I want and then if I recall correctly I use LAN to set the angles for each sat. 0,90,180,270 for four. And that works for EQ sats. But the moment I set inclination to 90 things get wonky. Sats get put on different planes relative to eacother and in retrograde orbits. How exactly can I use this tool to fix them? Truth be told I dont know what MNA, OBT ( orbit? ) or LAN means. Nor that new setting below.

## Recommended Posts

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34 minutes ago, Motokid600 said:

"Set Orbit" function

Huh?

The wiki (https://wiki.kerbalspaceprogram.com/wiki/Orbit) does a good job of explaining orbital abbreviations (well done, whoever wrote it).

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For polar orbits, you would want all the relays to have identical LAN (Longitude of Ascending Node).   It's either MNA or Argument of Periapsis you want to change for polar relays, but I can't remember which off the top of my head

Edited by Cavscout74

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Ah okay so its the MNA ive been manipulating MNA to get the spacing right, but that alone is setting sats in random orbits. Thank you ill try messing with LAN/ArgPe

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On 9/6/2019 at 2:02 PM, Motokid600 said:

Ah okay so its the MNA ive been manipulating MNA to get the spacing right, but that alone is setting sats in random orbits. Thank you ill try messing with LAN/ArgPe

Incidentally, "argument of periapsis" is basically irrelevant if they're in circular orbits.  It determines the orientation of the orbit, if it's an ellipse (one way to illustrate it is to picture an equatorial elliptical orbit-- "argument of periapsis" determines what longitude the periapsis falls at).

MNA is "mean anomaly at epoch" and is the parameter that specifies where in the orbit a satellite is, at a given time.  So if you want to have a family of satellites that all have exactly the same orbit but are just spaced at different points along that orbit, you'd want to give them all identical parameters but vary the MNA.

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On 9/6/2019 at 5:02 PM, Motokid600 said:

Ah okay so its the MNA ive been manipulating MNA to get the spacing right, but that alone is setting sats in random orbits.

How have you been manipulating MNA?  Are you using radians or degrees?  I am fairly certain that KSP uses radians for MNA, so you'll want to use numbers ranging from 0 to 2π (approximately equivalent to 6.2832).  For a constellation of four satellites, that would mean 0, 1.5708. 3.1416, and 4.7124.

Edited by Zhetaan

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