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W. J. Borucki (NASA Ames Research Center), E. T. Dunham (Lowell Observatory), D. G. Koch (NASA Ames Research Center), J. M. Jenkins (SETI Institute), F. Witteborn (none)
The concept of the Kepler Mission is to use transit photometry to determine the frequency of terrestrial-sized planets and their distributions of size and orbital characteristics around a variety of stellar types. The Kepler team has been funded by NASA to do an end-to-end laboratory demonstration of the approach that would be used to accomplish the mission objectives. The approach has two major components; a numerical model and a laboratory system designed to demonstrate that a CCD photometer can reach and maintain the required relative precision over a period of time necessary to detect the transits and in the presence of realistic noise sources. The photometric facility includes a simulated star field, fast optics to simulate the telescope, a CCD detector similar to the one to be used on the spacecraft, a computer to do the onboard data processing, and a second computer that receives the data from the onboard processor and then construct light curves and searches for transits. Specific objectives of the end-to-end test include; 1) Demonstrate a CCD photometer that can reach and continuously maintain an instrument relative precision of 1x10-5. 2) Demonstrate that it can reliably detect transit signals that are expected from an Earth-sized planet orbiting a solar-like star. 3) Move the camera relative to the fixed star field with amplitude and frequency to simulate spacecraft pointing errors. 4) Include effects of field rotation changes equivalent to what will occur when the spacecraft is rolled 90 degrees relative to the Sun. 5) Vary signal amplitudes with power spectral densities expected for typical stars.
The Kepler "test bed" facility has been constructed and tests are underway. Results from both the numerical and laboratory simulation are presented.