Satillite Network Orbital Question

[Zeniden]

I have a GPS mod that requires several satellites to be visible in an area at one time. Currently I want my GPS network to be at a circular orbit of around 750km. To make things smooth I want to position these satellites in symmetrical orbit. My pattern is sort of like an 8 point star in one network. I want these 8 satellites to orbit a specific inclination while another 8 orbit at a different given inclination (lets say 90 degrees from the first set). Is there a mod, a tool or a way to time it so that I can have each satellite opposite of it's parent? For example At hour one I launch GPS-1A (Satellite 1, Orbital path A) to a circular orbit of 750km. I want to Launch GSP-2A to be positioned around 180 degrees from GPS-1A with the same velocity and altitude. How do I do this? I do have Mechjeb installed and I know some of you aren't into mods but I am. However I am open minded and will try any advice be that modded or unmodded techniques. Thank you very much.

[Taki117]

The way I would do it is either launch multiple sats at once and establish a resonant orbit of 1/2 the period that you want with an apoapsis of 750km. This way when Sat A is at periapsis Sat B will be at apoapsis.

Another option is to launch them individually, place them in a parking orbit at 80km (Or some other arbitrary altitude below your target) and then set Sat A as your target and try and get the target markers 180 degrees apart using a maneuver node.

[xcorps]

What is a resonant orbit?

[Claw]

What is a resonant orbit?

Here's the long answer: http://en.wikipedia.org/wiki/Orbital_resonance

The short answer is that a resonant orbit is some multiple of each other. So if you had Satellite A in a 6 hour orbit, a 1/2 resonant orbit for Satellite B would be 3 hours. Satellite B makes 2 orbits for every 1 orbit of Satellite A.

What I think Taki is saying is to use an elliptical resonant orbit to deploy your satellites. Put your satellite launcher in a resonant orbit of your 750km orbit. Release Sat A at apoapsis and burn it to circularize. When your satellite launcher does 1 orbit, your Sat A will be on the other side of the 750km orbit, thereby allowing you to launch the second (opposite) satellite as you requested.

If you sent up a launcher that had all 8 of your satellites, you could set up a 1:8 resonant orbit with your launcher and release a satellite every time it reaches apoapsis. They would all be spaced 1/8th of an orbit apart.

The real trick with orbital networks in this game is that the satellites will drift. You need to work really hard to get the orbital periods (the time it takes to do a full orbit) as close to the same time as possible for all of your satellites. I mean get them within 1 second if possible. Many people use ION engines or RCS to do that. Orbital period is more important than getting matching AP/PEs. If you do it right, you can get the orbital period within a fraction of a second and you won't have to touch your satellites for a couple months.

Edited May 11, 2014 by Claw

[Zeniden]

Wow awesome ok thanks very much. I'll start practicing this.

[MrAnonymous]

You can also put them in geo-stationary orbit