TPF-I SWG Report - Exoplanet Exploration Program - NASA

C HAPTER 2
Table 2-2. Illustrative Properties of a TPF-I Observatory Concept*
Parameter
Telescopes
4-Telescope Dual Chopped Bracewell Design
Four 4-m diameter telescopes, diffraction limited at 2 μm operating at 40 K
Array size
60–150 m center-to-center of outer telescope in linear array
Baseline range
40–100 m
Wavelength range 6.5–15 µm, with the goal of 6.5–18 µm
Angular resolution (maximum) 50–75 milli-arcseconds
Field-of-view 1 arcsec at 12 µm
Spectral resolution Δλ/λ 25 with a goal of 50
Sensitivity 0.35 µJ at 12 µm
Number of stars 150
Biomarkers H 2 O and O 3 with a goal of also measuring CO 2 and CH 4
Field of regard
±45° of anti-Sun direction
Orbit
L2 Halo orbit
Mission duration
5 years baseline with a goal of 10 years
Mission launch
2019 with Heavy-class launch vehicle, Delta 4050H
*Further details are available in Appendix B
Visitations
Multiple visits per star will be required to achieve required completeness, to distinguish it from
background objects, to determine its orbit, and to study a planet along its orbit. TPF-I must be capable of
making at least 3 visits to each star to meet the completeness and other requirements.
Multiple Planets
After the completion of the required number of visitations defined above, TPF-I should be able to
characterize a planetary system as complex as our own with three terrestrial-sized planets assuming each
planet is individually bright enough to be detected.
Orbit Determination
After the completion of the required number of visitations defined above, TPF-I shall be able to localize
the position of a planet orbiting in the habitable zone with an accuracy of 10% of the semi-major axis of
the planet’s orbit. This accuracy may degrade to 25% in the presence of multiple planets.
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