Station-Keeping Maneuvers to Control the Inclination Evolution of Areostationary Satellites

Observing Mars from Areostationary Orbit: Benefits and Applications

“…An areostationary satellite would orbit Mars in a circular and equatorial orbit with a semi-major axis of as= 20,428 km (altitude of 17,031.5 km) to be at rest with respect to the rotating Mars with a period of one Martian sidereal day (sol): P= 88,642.663 s (see [2] for a derivation of the orbit characteristics). The locations having zero tangential acceleration correspond to two stable longitudes (17.92º W and 167.83º E) and two unstable longitudes (75.34º E and 105.55º W) [3].…”

“…The dominant disturbing forces on the orbit are perturbations due to the nonspherical mass distribution of the Mars gravitational field, the gravitational attraction of the Sun, the moons Phobos and Deimos (the areostationary orbit lies between the nearly equatorial orbits of the two moons, having as=9,376 km and as=23,463.2 km, respectively), and the Solar Radiation Pressure (SRP). These perturbations have been described and modeled in [3][4][5][6]. Here we simply note that the perturbations of the Mars gravitational field cause a change of the semimajor axis of the orbit that, in turn, induces a longitudinal drift; the attraction of the Sun and moons cause a change of the orbit's inclination and, consequently, latitudinal oscillations; SRP causes a change of the mean eccentricity vector that also contributes to the longitudinal drift.…”

“…As with geostationary satellites, areostationary ones would therefore require station keeping maneuvers to counteract natural perturbations. With the exception of stable longitudes, on average, areostationary eastwest station keeping requires a lot more Δv than geostationary [3][4]; conversely, north-south station keeping requires less Δv because Mars's moons are smaller and the Sun is farther The ideal areostationary orbit has its sub-spacecraft point fixed in longitude at the equator at a fixed altitude. If the orbit is maintained with station keeping maneuvers, it is possible to:…”