Efficient search of optimal Flower Constellations

We derive an analytical closed expression to compute the minimum distance (quantified by the angle of separation measured from the center of the Earth) between any two satellites located at the same altitude and in circular orbits. We also exploit several properties of Flower Constellations (FCs) that, combined with our formula for the distance, give an efficient method to compute the minimum angular distance between satellites, for all possible FCs with up to a given number of satellites.