Lyapunov Feedback Control in Equinoctial Elements Applied to Low Thrust Control of Elliptical Orbit Constellations

For a typical satellite constellation design problem, sometimes there are two conflicting goals. On one hand one wishes to provide continuous coverage of a particular area. On the other hand one would like to use the minimum number of satellites as possible. For coverage locations nearer the equator, these requirements are easily fulfilled by using a satellite in a geostationary orbit. However, coverage of higher latitude locales is not as effective with geostationary satellites because the viewing angle from the ground to the satellite will be closer to the horizon, which increases the likelihood of loss of signal due to some ground obstacle. Instead, a constellation consisting of satellites in eccentric orbits at high inclination angles, sometimes referred to as Molniya type orbits, can circumvent this problem and provide continuous coverage with very few satellites. Elliptic-inclined constellations have been flown since the 1960s, chiefly by the governments of the former Soviet Union and the current Russian Federation. Not until the year 2000 has such a constellation been flown commercially. With the involvement o