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Active wavefront control challenges of the NASA Large Deployable Reflector (LDR)The 20-m Large Deployable Reflector will have a segmented primary mirror. Achieving diffraction-limited performance at 50 microns requires correction for the errors of tilt and piston of the primary mirror. This correction can be obtained in two ways, the use of an active primary or a correction at a demagnified pupil of the primary. A critical requirement is the means for measurement of the wavefront error and maintaining phasing during the observation of objects that may be too faint for determining the error. Absolute phasing can only be determined using a cooperative source. Maintenance of phasing can be done with an on-board source. A number of options are being explored as discussed below. The many issues concerning the assessment and control of an active segmented mirror will be addressed with an early construction of the Precision Segmented Reflector testbed.
Document ID
19900043834
Document Type
Conference Paper
Authors
Meinel, Aden B. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Meinel, Marjorie P. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Manhart, Paul K. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Hochberg, Eric B. (JPL Pasadena, CA, United States)
Date Acquired
August 14, 2013
Publication Date
January 1, 1989
Subject Category
OPTICS
Meeting Information
Active Telescope Systems(Orlando, FL)
Distribution Limits
Public
Copyright
Other