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how to deploy satellites so they are evenly distributed throughout the orbit?

Question

I can't get my 3 satellite configuration nice and exactly 120deg from each other, hell I can't get them even close to it!

How can I build a ship that deploys all 3 at once and correctly?

Can someone who knows how to do this make a tutorial video for it?

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the easiest way is to set up a resonant orbit and deploy your sats with enough dV to circularize their orbits. (a couple hundred m/s should do it.)

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The easiest way to deploy three evenly spaced satellites in a single launch depends on whether you have any propulsion on the satellites.

Basically, what you want to do is put your launching craft into an orbit where the apoapsis is at the desired altitude, but the periapsis is low enough that the orbital period is 0.666 times the desired orbital period. For example, if you're going for a 6 hour orbit for your satellites, the orbit of your launching craft should have a four hour period.

Then, each time you arrive at your apoapsis, you launch one of the satellites. If the satellites have enough propulsion to circularize themselves, this is quite easy. If they don't, it means circularizing the launching craft, launching the satellite, then dropping the periapsis back down to have the correct orbital period.

Note that a 6 hour orbit is no longer a geosynchronous orbit. 0.24 slightly tweaked kerbin's rotational period.

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The easiest way to deploy three evenly spaced satellites in a single launch depends on whether you have any propulsion on the satellites.

Basically, what you want to do is put your launching craft into an orbit where the apoapsis is at the desired altitude, but the periapsis is low enough that the orbital period is 0.666 times the desired orbital period. For example, if you're going for a 6 hour orbit for your satellites, the orbit of your launching craft should have a four hour period.

Then, each time you arrive at your apoapsis, you launch one of the satellites. If the satellites have enough propulsion to circularize themselves, this is quite easy. If they don't, it means circularizing the launching craft, launching the satellite, then dropping the periapsis back down to have the correct orbital period.

Note that a 6 hour orbit is no longer a geosynchronous orbit. 0.24 slightly tweaked kerbin's rotational period.

Offcourse the same thing also works with periaps at desired altitude, and apoaps high enough to be resonant

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Offcourse the same thing also works with periaps at desired altitude, and apoaps high enough to be resonant

Correct, I even thought of mentioning that, but I've never found a reason to do that rather than the apoapsis method. If you're having to shift the main craft between the circular orbit and the resonant orbit, the periapsis method might be more delta-v-efficient, especially if you're launching more than three satellites. I'm not sure as I've never tried it and never done the math, I always have enough maneuver power on the satellites that they can handle their own circularization, at which point the periapsis method is less efficient if you're placing them in orbit of the body you're launching from.

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Surely over time they would fall out of resonance as you wouldn't be able to get them exactly equal. Next mission when you time warp to Duna or something you would come back and they would be random!!

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There is no way to get three satellites to *exactly* match their orbits.

You can get close though.

Just plonk all three in more-or-less the desired altitude. They will drift anyways, so why bother finetuning it too much.

Now pick the one that is closest to the orbital period you want. Write that down.

Go to the others. burn pro/retro until you have the orbital period matching to the desired precision.

dont worry about the exact shape of the orbit, all that matters is that the period matches.

If you get their orbital period within one second, then for a kerbal "geosynch" orbit, which is roughly 6 hours (21600 seconds), then it will take 3600 kerbal days for the relative position of your satellites to drift by 60 degrees.

Get the period within 0.01 second, and your trio should be stabile(+- 60 degrees), for 850 Kerbal years. That should be close enough.

As for launching all three, *at the same time*, unpropelled, from one ship?

"How can I build a ship that deploys all 3 at once and correctly?"

Easy!

Just use the same technique you would use when having one person drive three cars from Denver to Orlando, NewYork and SanFransisco , at the same time.

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You're gonna have to raise and lower orbits like a rendezvous, but instead of targetting a ship you need to target an abstract point in space. You could try targetting one of your other satellites and adjust your 'closest approach' arrows until they're about 120 degrees apart. Also, since it's pretty much impossible to get a perfectly circular orbit, they're going to drift relative to each other over time, especially if they don't have the same semi-major axis.

The only way you'll launch them into that orbit from one rocket is if all three satellites have their own propulsion. You could try:

1. Put your drop ship in a highly elliptical orbit, with apoapsis at the desired height and an orbital period of about one third of the orbital period of a circular orbit at desired height.

2. Drop the first satellite, and use its rocket to circularize.

3. Repeat step two for the other two satellites.

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You mean evenly spaced along the same orbital path? You know how to dock to a ship in orbit or rescue a Kerbonaut? Just do the same process for an imaginary dot 120 degrees off from your last satellite. Target last satellite, orbit a little faster than it, then at the right time burn out to the closest intercept with the imaginary dot (not the satellite). When there, kill speed relative to satellite. Basically, just intercept the last satellite behind it by 120 degrees.

I am at work instead of playing KSP, so I may be brain farting. But it seems easy enough.

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1. Get them in orbit.

2. Edit persistence file.

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I've created an Excel Workbook that will calculate this:  You can find it here:  Satellite Spacing Calculator

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10 hours ago, StevenLawyer said:

I've created an Excel Workbook that will calculate this:  You can find it here:  Satellite Spacing Calculator

Holy necro Batman.

There's a nice tool since several years back.
https://meyerweb.com/eric/ksp/resonant-orbits/

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Matt Lowne has a really nice tutorial for making a relay network, and he demonstrates how to get them an equal distance from each other.

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