A Caltech Library Service

Pre-Construction Progress of Giant Steerable Science Mirror for TMT

Fei, Yang and Hongchao, Zhao and Qichang, An and Peng, Guo and Haibo, Jiang and Linchu, Han and Ford, Virginia and Cole, Glen and Smith, Byron and Campbell, Marvin (2016) Pre-Construction Progress of Giant Steerable Science Mirror for TMT. In: Ground-based and Airborne Telescopes VI. Proceedings of SPIE. No.9906. Society of Photo-Optical Instrumentation Engineers (SPIE) , Bellingham, WA, Art. No. 99064M. ISBN 978-1-5106-0191-8.

[img] PDF - Published Version
See Usage Policy.


Use this Persistent URL to link to this item:


The Changchun Institute of Optics, Fine Mechanics and Physics (CIOMP) team is developing the Giant Steerable Science Mirror (GSSM) for Thirty Meter Telescope (TMT) which will enter the preliminary design phase in 2016. The GSSM is the tertiary mirror of TMT and consists of the world’s largest flat telescope mirror (approximately 3.4m X 2.4 m X 100mm thick) having an elliptical perimeter positioned with an extremely smooth tracking and pointing mechanism in a gravity-varying environment. In order to prepare for developing this unique mirror system, CIOMP has been developing a 1/4 scale, functionally accurate version of the GSSM prototype during the pre-construction phase of GSSM. The prototype will incorporate the same optomechanical system and servo control system as the GSSM. The size of the prototype mirror is 898.5mm×634mm×12.5mm with an elliptical perimeter. The mirror will be supported axially by an 18 point whiffletree and laterally with a 12 point whiffletree. The main objective of the preconstruction phase includes requirement validation and risk reduction for GSSM and to increase confidence that the challenge of developing the GSSM can be met. The precision mechanism system and the optical mirror polishing and testing have made good progress. CIOMP has completed polishing the mirror, the prototype mechanism is nearly assembled, some testing has been performed, and additional testing is being planned and prepared. A dummy mirror is being integrated into the cell assembly prototype to verify the design, analysis and interface and will be used when testing the prototype positioner tilt and rotation motions. The prototype positioner tilt and rotator structures have been assembled and tested to measure each subsystem’s jitter and dynamic motion. The mirror prototype has been polished and tested to verify the polishing specification requirement and the mirror manufacturing process. The complete assembly, integration and verification of the prototype will be soon finished. Final testing will verify the prototype requirements including mounted mirror surface figure accuracy in 5 different orientations; rotation and tilt motion calibration and pointing precision; motion jitter; and internally generated vibrations. CIOMP has scheduled to complete the prototype by the end of July 2016. CIOMP will get the sufficient test results during the pre-construction phase to prepare to enter the preliminary design for GSSM.

Item Type:Book Section
Related URLs:
URLURL TypeDescription
Additional Information:© 2016 Society of Photo-Optical Instrumentation Engineers (SPIE).
Subject Keywords:Giant Steerable Science Mirror, Prototype of GSSM, TMT, Large Aperture Telescope
Series Name:Proceedings of SPIE
Issue or Number:9906
Record Number:CaltechAUTHORS:20170111-075813425
Persistent URL:
Official Citation:Fei Yang ; Hongchao Zhao ; Qichang An ; Peng Guo ; Haibo Jiang ; Linchu Han ; Virginia Ford ; Glen Cole ; Byron Smith ; Marvin Campbell; Pre-construction progress of giant steerable science mirror for TMT . Proc. SPIE 9906, Ground-based and Airborne Telescopes VI, 99064M (July 27, 2016); doi:10.1117/12.2232068.
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:73408
Deposited By: Ruth Sustaita
Deposited On:11 Jan 2017 21:15
Last Modified:03 Oct 2019 16:27

Repository Staff Only: item control page