TITLE: Parking a spacecraft near an asteroid pair AUTHORS: F. Gabern^(1,2), W.S. Koon^(1) and J.E. Marsden^(1) (1) Control and Dynamical Systems, 107-81 California Institute of Technology 1200 East California Boulevard Pasadena, CA 91125, USA (2) Departament de Matematica Aplicada i Analisi, Universitat de Barcelona, Gran Via 585, 08007 Barcelona, Spain ABSTRACT: The purpose of this paper is to study the dynamics of a spacecraft moving in the field of a binary asteroid. The asteroid pair is modeled as a rigid body and a sphere moving in a plane, while the spacecraft moves in their field in space. This model is interesting because it is one of the simplest that captures the coupling between rotational and translational dynamics. By assuming that the binary dynamics is in a relative equilibrium, a restricted model for the spacecraft in orbit about them is constructed that also includes the direct effect of the Sun on the spacecraft dynamics. The standard Restricted Three Body Problem (RTBP) is used as starting point for the analysis of the spacecraft motion. In particular, how the triangular points of the RTBP are modified through perturbations is investigated by taking into account two sorts of perturbations, namely that one of the primaries is no longer a point mass but is an extended rigid body, and second, taking into account the effect of orbiting the Sun. The stable zones near the modified triangular equilibrium points of the binary and a normal form of the Hamiltonian around them are used to compute stable periodic and quasi-periodic orbits for the spacecraft, which enable it to observe the asteroid pair while the binary orbits around the Sun. ------------------------------- e-mails: gabern@cds.caltech.edu koon@cds.caltech.edu marsden@cds.caltech.edu