Analyzing the Designs of Planet-Finding Missions

作者:Savransky Dmitry*; Kasdin N Jeremy; Cady Eric
来源:Publications of the Astronomical Society of the Pacific, 2010, 122(890): 401-419.
DOI:10.1086/652181

摘要

We present a framework for the analysis of direct detection planet-finding missions using space telescopes. This framework generates simulations of complete missions, with varying populations of planets, to produce ensembles of mission simulations, which are used to calculate distributions of mission science yields. We describe the components of a mission simulation, including the complete description of an arbitrary planetary system, the description of a planet-finding instrument, and the modeling of a target system observation. These components are coupled with a decision- modeling algorithm that allows us to automatically generate mission time-lines with simple mission rules that lead to an optimized science yield. Along with the details of our implementation of this algorithm, we discuss validation techniques and possible future refinements. We apply this analysis technique to four mission concepts whose common element is a 4 m diameter telescope aperture: an internal pupil mapping coronagraph with two different inner working angles, an external occulter, and the THEIA XPC multiple distance occulter. The focus of this study is to determine the ability of each of these designs to achieve one of their most difficult mission goals-the detection and characterization of Earthlike planets in the habitable zone. We find that all four designs are capable of detecting on the order of five Earthlike planets within a 5 yr mission, even if we assume that only one out of every 10 stars has such a planet. The designs do differ significantly in their ability to characterize the planets they find. Along with science yield, we also analyze fuel usage for the two occulter designs, and discuss the strengths and weaknesses of each of the mission concepts.

  • 出版日期2010-4