Searching for life with the Terrestrial Planet Finder: Lagrange point options for a formation flying interferometer C. Beichman, G. Gomez, M. Lo, J. Masdemont and L. Romans Abstract. Whether life exists beyond Earth is a fundamental question. To answer this and related questions requires access to space making the search for life within our solar system and beyond a quest that only the National Aeronautics and Space Administration (NASA), along with its international partners, can answer. The Terrestrial Planet Finder (TPF) is one of the key missions in NASA's Astronomical Search for Origins. In this paper, we describe the mission design for TPF assuming a distributed spacecraft concept using formation flight around both a halo orbit about the Sun-Earth L2 as well as a heliocentric orbit. Although the mission architecture is still under study, the next two years will include study of four design concepts and a down select to two concepts around 2005. TPF is anticipating a Phase A start around 2007 and a launch sometime around 2015.