TITLE: Simulation of Formation Flight Near L2 for the TPF Mission AUTHORS: G. Gomez Departament de Matemātica Aplicada i Anālisi Universitat de Barcelona, 08007 Barcelona, Spain e-mail: gerard@maia.ub.es M.W. Lo Navigation and Mission Design Jet Propulsion Laboratory, California Institute of Technology M/S 301-140L Pasadena, California 91109, USA e-mail: mwl@hari.jpl.nasa.gov J. Masdemont Departament de Matemātica Aplicada I ETSEIB Universitat Politčcnica de Catalunya Diagonal 647, 08028 Barcelona, Spain e-mail: josep@barquins.upc.es K. Museth Computer Science Graphic Group California Institute of Technology Pasadena, California, USA e-mail: kmu@gg.caltech.edu ABSTRACT: The TPF Mission (Terrestrial Planet Finder) is one of the center pieces of the NASA Origins Program. The goal of TPF is to identify terrestrial planets around stars nearby the Solar System. For this purpose, a space-based infrared interferometer with a baseline of approximately 100 m is required. To achieve such a large baseline, a distributed system of five spacecraft flying in formation is an efficient approach. Since the TPF instruments needs a cold and stable environment, near Earth orbits are unsuitable. Two potential orbits have been identified: a SIRTF-like heliocentric orbit; a libration orbit near the L2 Lagrange point. In this paper, we focus on the second case: an orbit near the L2 Lagrange point. The formation flight problem near the Lagrange points is of great interest. Our work in the study of the feasibility of formation flight near the Lagrange points indicates that: 1. Formation flight near L2 is dynamically possible for the TPF Mission. 2. Linear control around a nonlinear baseline libration orbit near L2 is adequate for the TPF Mission.