Modeling of light curve observables for binary asteroid systems

The objective of this thesis is to develop and validate models of light curve observables for binary asteroid systems using JPL's astrodynamics software, MONTE. The potential of light curves lies in their ability to observe mutual events intervals during which one of the two bodies prevents the other from reflecting sunlight toward Earth, either by occulting its view or directly blocking sunlight. These events generate a drop in the light curve, whose measured depth and duration are used to derive key parameters of the asteroid system. This analysis focuses on the Didymos binary system, the target of AIDA's Planetary Defense missions DART and HERA. After collecting existing light curve data from online repositories, three different observable models are tested. Two of these models involve the direct calculation of the system's luminosity over time, while the third, named Contact times model, only computes the time instants that characterize mutual events. This method was first employed in 2022 by Naidu et al., using NAIF's toolkit SPICE to calculate the intervals. Despite its relative simplicity, the model is able to employ real light curve data to carry out an estimation of the Didymos system's rotational dynamics. Given its flexibility, reliability, and straightforwardness, this thesis explores the feasibility of implementing this model in MONTE, providing an alternative perspective on Naidu's analysis by using a different software. Using the same measurements from 2003 to 2021 and a similar dynamical setup, the results are consistent with the reference solution, both in terms of estimated parameters and uncertainties. Having achieved its initial goal, this work aims to contribute to the advancement of light curve modeling for deep-space navigation. Its application should be extended to improve the knowledge of many other binary asteroid systems, further enhancing the importance of Planetary Defense in the future of space exploration.