The presentation will focus on the dynamics of space debris in the Earth
environment, with a celestial mechanics and theoretical point of view, and not
with an operational perspective. Concretely it will be divided in 6 parts:
1. I shall present the Earth space junk, with the description and the evolution
of the debris population, and describe the main forces acting on them, their
relative importance and the main regions of interest (Low, Medium and
Geostationary Orbits, later called LEO, MEO and GEO).
2. The resonances are present at several levels : gravitational resonances, for
MEO and GEO, but also lunar-solar resonances, and secondary resonances
involving the Sun. A classical Hamiltonian approach is proposed for GEO
or MEO regions, with different associated toys models.
3. Some numerical integrations, their limits, their characteristics, symplectic
or not, for short or long time integrations will be presented, commented
and compared. Chaotic indicators (MEGNO in particular) are connected,
and allow to put the stability of some regions into perspective.
4. The solar radiation pressure will be investigated with more details, without
or with shadowing effects especially in the GEO region.
5. For the LEO, the atmospheric drag plays an important role on the dynamics,
dependent on the ballistic coefficient. Some comparisons will be
presented, concerning the solar activity and the consequences on the reentry
times.
6. A few words about the rotation of the debris, the explosions and collisions
mechanisms, and the possibility to simulate those events in a synthetic
population will conclude the course.