A dynamic and spectrophotometric study of Russian Molniya/Meridian satellite constellation

In this thesis work we carried out an analysis of the spectrophotometric and dynamical characteristics of Molniya and Meridian satellites constellation. Our work falls within the context of space debris Science and in particular the study of space debris in order to create a starting base for the resolution of the Kessler syndrome problem. We based mainly on spectrophotometric observations made with the Cassini telescope. In this work we focused on four main topics: - The study of rotational instabilities that Molniya satellite develop after they went out of control and their temporal evolution. Were possible we extracted the tumbling period from the light curves. We build then a phenomenological model to reproduce the observed spindown rate of tumbling period. The model is an exponential with characteristic time 28.44 years. - The study of gravitational instabilities of Molniya type orbit. Solar-lunar perturbations tend to bring the satellite near the atmospheric drag zone causing the re-entry into atmosphere. - The relation that ties the apparent magnitude and the phase angle. We developed four models to explain the observed decreasing trend of magnitude with increasing phase angle. The best-fit model was the spherical lambertian model. Considering the reflecting area equal to RCS, we calculated a lower limit to the albedo, 0.09 for filter B, 0.28 I, 0.15 R and 0.10 V. - The study of spectral properties and color indexes of Molniya debris. We built color-color diagrams to search for color evolution with age, to understand reflective capacities and to compare the colors of the satellites with material colors. Spectral analysis was carried out calculating the reflectance of Molniya debris and compare it with materials reflectance. Confirming albedo values Molniya satellites present high reflective capacities in band I, that decrases in R, V and B. No trend has been found with age and in general there's disagreement with materials features.