TPF-I SWG Report - Exoplanet Exploration Program - NASA

Abstract
Over the past two years, the focus of the project for the interferometric version of the Terrestrial Planet
Finder (TPF-I) has been on the development of the scientific rational for the mission, the assessment of
TPF-I architectures, the laboratory demonstration of key technologies, and the development of a detailed
technology roadmap. The Science Working Group (SWG), in conjunction with European colleagues
working on the European Space Agency’s (ESA’s) Darwin project, has reaffirmed the goals of TPF-I as
part of a broad vision for the detection and characterization of Earth-like planets orbiting nearby stars and
for the search for life on those planets. The SWG also helped to assess the performance of different
interferometric configurations for TPF-I/Darwin. Building on earlier SWG reports, this document restates
the scientific case for TPF-I, assesses suitable target stars and relevant wavelengths for observation,
discusses dramatic new capabilities for general astrophysical observations, and summarizes how Spitzer
has improved our knowledge of the incidence of zodiacal emission on the search for planets. This
document discusses in some detail on laboratory advances in interferometric nulling and formation flying.
Laboratory experiments have now achieved stable narrow- and broad-band nulling the levels of 10 -6 and
2.0×10 -5 , respectively. A testbed has demonstrated formation flying using two realistic spacecraft
mockups. With a suitably funded program of technology development, as summarized herein and
described in more detail in the Technology Plan for the Terrestrial Planet Finder Interferometer (2005),
the National Aeronautics and Space Administration (NASA) and ESA would be able to start within the
coming decade a full-scale TPF-I/Darwin mission capable of finding Earths orbiting more than 150
nearby stars, or a scaled back interferometer capable of studying more than 30 stars. Finding evidence for
life on just one of those planets would revolutionize our understanding of our place in the cosmos.
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