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Vacuum Nuller Testbed (VNT) Performance, Characterization and Null Control: Progress ReportHerein we report on the development. sensing and control and our first results with the Vacuum Nuller Testbed to realize a Visible Nulling Coronagraph (VNC) for exoplanet coronagraphy. The VNC is one of the few approaches that works with filled. segmented and sparse or diluted-aperture telescope systems. It thus spans a range of potential future NASA telescopes and could be Hown as a separate instrument on such a future mission. NASA/Goddard Space Flight Center (GSFC) has a well-established effort to develop VNC technologies. and has developed an incremental sequence of VNC testbeds to advance this approach and the enabling technologies associated with it. We discuss the continued development of the vacuum Visible Nulling Coronagraph testbed (VNT). Tbe VNT is an ultra-stable vibration isolated testbed that operates under closed-loop control within a vacuum chamber. It will be used to achieve an incremental sequence of three visible-light nulling milestones with sequentially higher contrasts of 10(sup 8), 10(sup 9) and ideally 10(sup 10) at an inner working angle of 2*lambda/D. The VNT is based on a modified Mach-Zehnder nulling interferometer, with a "W" configuration to accommodate a hex-packed MEMS based deformable mirror, a coherent fiber bundle and achromatic phase shifters. We discuss the initial laboratory results, the optical configuration, critical technologies and the null sensing and control approach.
Document ID
20110023045
Acquisition Source
Goddard Space Flight Center
Document Type
Preprint (Draft being sent to journal)
Authors
Lyon, Richard G.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Clampin, Mark
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Petrone, Peter
(Sigma Space, Inc. Lanham, MD, United States)
Mallik, Udayan
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Madison, Timothy
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Bolcar, Matthew R.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Noecker, M. Charley
(Ball Aerospace and Technologies Corp. Boulder, CO, United States)
Kendrick, Stephen
(Ball Aerospace and Technologies Corp. Boulder, CO, United States)
Helmbrecht, Michael
(IRIS Adaptive Optics, Inc. Berkeley, CA, United States)
Date Acquired
August 25, 2013
Publication Date
August 21, 2011
Subject Category
Lunar And Planetary Science And Exploration
Report/Patent Number
GSFC.O.5212.2011
Meeting Information
Meeting: SPIE 2011
Location: San Diego, CA
Country: United States
Start Date: August 21, 2011
End Date: August 25, 2011
Sponsors: International Society for Optical Engineering
Distribution Limits
Public
Copyright
Public Use Permitted.
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