TPF-I SWG Report - Exoplanet Exploration Program - NASA

C HAPTER 5
planets found. Figure 5-22 compares the planets surveyed by TPF-I and TPF-C, as well as the masssensitivity
of the Space Interferometry Mission (SIM-PlanetQuest). The coronagraph approach of
maximizing the number of planets found is currently being applied to the interferometer so that we can
better compare the relative performance of the two missions.
Table 5-2. Parameters Assumed for the Prediction of the Number of Stars Surveyed
Parameter
Constraint
Mission time available for survey
2 yr
Fraction of survey time spent integrating 50%
Number of visits per star for 90% completeness 3
Solar shading constraint
±45 deg anti-Sun
30
25
All (1014)
1 Earth mass (241)
0.5 Earth mass (156)
0.1 Earth mass (57)
Distance / pc
20
15
10
5
0
0 50 100 150 200
Projected radius of Inner Habitable Zone / mas
Figure 5-20. Number of systems surveyed in 2-year mission time as a function of the mass
sensitivity. 57 stars are covered with a deep survey down to 0.1 Earth mass limit (yellow). 156
targets are covered with medium depth survey to 0.5 Earth mass limit (yellow + green). 241 targets
are covered with shallow survey to 1 Earth mass limit (yellow + green + blue). These are mutually
exclusive scenarios.
120