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Optical Engineering • Open Access

Telescope with 100 square degree field-of-view for NASA’s Kepler mission
Author(s): Dennis Ebbets; Chris K. Stewart; Peter Spuhler; Paul Atcheson; Jeffrey Van Cleve; Stephen T. Bryson; Andrew R. Clarkson; John Barentine

Paper Abstract

Kepler is NASA’s first space mission dedicated to the study of exoplanets. The primary scientific goal is statistical—to estimate the frequency of planetary systems associated with sun-like stars, especially the detection of earth-size planets in the habitable zones. Kepler was launched into an Earth-trailing heliocentric “drift-away” orbit (period=372  days ) in March 2009. The instrument detects the faint photometric signals of transits of planets across the stellar disks of those systems with orbital planes fortuitously oriented in our line of sight. Since the probability of such alignments is small, Kepler must observe a large number of stars. In fact, Kepler is monitoring approximately 150,000 stars with a 30-min cadence. The scientific goals led to the choice of a classical Schmidt telescope, and requirements on field-of-view, throughput, spectral bandpass, image quality, scattered light, thermal and opto-mechanical stability, and in-flight adjustment authority. We review the measurement requirements, telescope design, prelaunch integration, alignment, and test program, and we describe the in-flight commissioning that optimized the performance. The stability of the flight system has enabled increasing recognition of small effects and sophistication in data processing algorithms. Astrophysical noise arising from intrinsic stellar variability is now the dominant term in the photometric error budget.

Paper Details

Date Published: 22 May 2013
PDF: 9 pages
Opt. Eng. 52(9) 091808 doi: 10.1117/1.OE.52.9.091808
Published in: Optical Engineering Volume 52, Issue 9
Show Author Affiliations
Dennis Ebbets, Ball Aerospace & Technologies Corp. (United States)
Chris K. Stewart, Ball Aerospace & Technologies Corp. (United States)
Peter Spuhler, Ball Aerospace & Technologies Corp. (United States)
Paul Atcheson, Ball Aerospace & Technologies Corp. (United States)
Jeffrey Van Cleve, NASA Ames Research Ctr. (United States)
Stephen T. Bryson, NASA Ames Research Ctr. (United States)
Andrew R. Clarkson, L-3 Brashear (United States)
John Barentine, ThAcEnWIN LLC (United States)


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