4 juin - 7 juin 2013


S06 Astrom├ętrie de haute pr├ęcision et applications

Resonances due to third body perturbations in the dynamics of MEOs

Letizia Stefanelli, Gilles Metris

The dynamics of Medium Earth Orbits (MEO) sees nowadays a renewed

interest because of the development of satellites constellations

(GNSS), that raises the problem of parking orbits for satellites at

end of life. Numerical evidence shows that the resonances related to

the presence of a third body can affect the stability of MEO orbits.

The goal of our work is to study the effects of resonances on the

stability of MEO orbits, over long or very long term (hundreds of

years). For orbits above 20,000 km altitude, the perturbation due to a

third body (the Moon or the Sun) is not fully negligible, so we take

into account the third body perturbation on the secular evolution of

the angular variable of the satellite orbits, and thus of the resonant

angle. We estimate numerically the evolution of the resonant

inclination. We study the stability of some resonances analytically

and numerically, and in particular the resonance associated to the

operational inclination of the Galileo satellites.