Precise Solar Radiation Pressure Models for Small-Body Orbiters: Applications to OSIRIS-REx Spacecraft

This paper presents a framework for the precise representation of solar radiation pressure effects on spacecraft orbiting around small bodies. It uses a Fourier-series expansion to model the solar radiation force that is imparted on the spacecraft. A set of dominant Fourier coefficients that account for a majority of the solar radiation pressure effect and its uncertainty is identified. Analytical solutions are derived to shed light on the secular effects of solar radiation pressure on the orbit of spacecraft around small bodies. As an example application, this framework is implemented for the precise estimation of solar radiation pressure effects on the Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer spacecraft in orbit about asteroid (101955) Bennu. A set of error analyses and covariance studies are carried out for this spacecraft to evaluate the expected level of estimation precision that is feasible for the dominant Fourier coefficients.