The Terrestrial Planet Finder Interferometer (TPF-I) is a future NASA mission for mid-infrared astronomy in space, using formation flying to position the telescopes. A unique and significant challenge for TPF-I is control of stray light from thermally emitting objects near the starlight beam paths, such as sunshades and other warm parts of the neighboring spacecraft. A proposed strategy for stray light control in these missions is simple geometric shading of the beam-transport optics from the emitting objects, but this intrinsically limits the maximum inter-spacecraft separation. We present a preliminary study of diffractive beam propagation to set lower limits on the baffle diameters. This and other geometric constraints then lead to specific estimates of the maximum inter-spacecraft separation.

Date Published: 14 September 2005
PDF: 11 pages
Proc. SPIE 5905, Techniques and Instrumentation for Detection of Exoplanets II, 590504 (14 September 2005); doi: 10.1117/12.620314

Published in SPIE Proceedings Vol. 5905:
Techniques and Instrumentation for Detection of Exoplanets II
Daniel R. Coulter, Editor(s)