Orbital Stability Regions for Hypothetical Natural Satellites of (101955) Bennu

Abstract

The Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer (known as OSIRIS-REx) mission will orbit and return a sample from near-Earth asteroid (101955) Bennu. Ground-based observations determined that no object greater than 15 m in diameter is orbiting around Bennu. This investigation explores the potential size and stability of natural satellites of less than 15 m in diameter to provide predictions for where such small satellites should be searched for upon arrival. The focus is solely on the existence of stable orbits for natural satellites. How the natural satellite migrated to this orbit is purposefully placed outside the bounds of this study. The numerical model includes of Bennu, third-body dynamics from the sun, and solar radiation pressure. This model is used with the initial conditions of various semimajor axes, inclinations, the longitude of the ascending nodes, and natural satellite diameters. To be stable, it is required that a set of initial conditions must remain in orbit for greater than 1000 years. The possible existence of natural satellites in orbit around Bennu as small as 0.75 cm is found. Certain mechanisms such as the modified Laplace plane, the Kozai resonance, and sun-synchronous orbits help explain the stability of some orbits.