N. Kasdin/Princeton University

We propose to advance the readiness of the three riskiest key technologies associated with occulter-based planet finding and characterization---(1) manufacturing and deploying a large starshade to the needed accuracy, (2) developing station-keeping algorithms and verifying the precision necessary for the telescope/occulter combination, and (3) developing planet detection and characterization algorithms with realistic errors, both static and dynamic. We are proposing to develop an integrated laboratory and simulation program that involves manufacturing subscale starshade petals using flight- like processes, testing deployment accuracy, performing thermal and dynamic testing against requirements, performing optical scatter tests on petal edges, developing a complete model of the occulter system and its errors, and using the model to simulate observations and analysis of realistic images. In order to set requirements and verify overall performance, additional modeling and simulation tools will be developed and used to support the technology studies. Using these tools, we will develop a complete model of an occulter planet finding system, including dynamic variations and precise optical propagation. We will use this model to create simulated images that will support the planet extraction algorithm development. These analyses will, in turn, provide feedback for developing a complete error budget from which we will derive requirements on the starshade manufacturing, deployment, and stability. Part of this model will include a detailed thermal-mechanical analysis of the starshade incorporating realistic modeling of the environment that produces static, quasi-static, and dynamic distortions.

Specific starshade designs will be chosen based on our experience designing occulter missions (flagship missions with large telescopes, smaller missions with 1 to 1.5 m telescopes, and limited ground based activities using Earth orbiting occulters). The modeling and simulation results will be used to set requirements on the occulter and make performance predictions with regard to detection and characterization. These will be used in Monte-Carlo based mission simulations to verify science yield. Finally, current laboratory tests of the occulter (under separate funding) will provide verification of the optical modeling and provide real image-plane scatter for algorithm development and test.

Technology Development for Exoplanet Missions
Solicitation NNH09ZDA001N-TDEM