Calculating distance between 2 Sattelites every orbit cycle.

[Dmetrey]

Hi, I have tried googling and all but im not even sure how exactly to call this. Basicly i am trying to search for a formula with wich i can calculate the diffrence in separation distance between 2 objects every orbit cycle. This will be usefull for me when making synch communication satellite orbits using the least amout of time and fuel. My guess this formula will include Ap-Pe of both objects and time for one orbit. Maybe someone already has such formula? As for now i will continue searching...

[Stone Blue]

Maybe Visual RemoteTech Planner

 

[Evanitis]

Do you need an actual formula to calculate that on paper? That's not my cup-of-tea, but manuver nodes can just display this, even in stock. If you right click the node, there are two small buttons that move the maneuver between future passes of the orbit.

These buttons: http://wiki.kerbalspaceprogram.com/images/5/55/TwoBlue.jpg

 

Edited January 2, 2016 by Evanitis

[Antaro]

I am not sure if I have understood properly your question... Are you asking the separation between two spacecraft per each orbit? (so the units would be something like seconds per orbit)

[maltesh]

If the orbits are circular (and in the same plane),  the change in angular separation is constant, so if you know the angular separation at any particular time, you can use that to find the angular separation at any future time, and then, with two sides (the radius of both orbits) and the angle between them, you can use the Law of Cosines to work out the distance between the two satellites at any arbitrary time in the future.

If either, or both of the orbits are elliptical (but still coplanar), things get a lot more complicated, and you have to work out the separation angle between their periapses, work through Kepler's equations for True Anomaly as a Function of time to get the positions of each of the two satellites at the arbitrary time that you're checking, and then you can use the law of cosines.

If the two orbits are not coplanar...then  you're probably locked into solving Kepler's equations, converting to Cartesian coordinates, and using the distance formula.

Edited January 3, 2016 by maltesh