For polishing the ultra-thin TMT M3MP, a polishing support system with 18 hydraulic supports (HS) is introduced. This
work focuses on the designing and testing of these HSs. Firstly the design concept of HS system is discussed; then
mechanical implementation of the HS structure is carried out, with special consideration of fluid cycling, work
pressurization and the weight component. Afterward the piping installation and the de-gas process for the working fluid
are implemented. Pressurization and stiffness are well checked before system integration for the single HS unit. Finally
the support system is integrated for the polishing process.
The PSS (pentaprism scanning system) has advantages of simple structure, needless of reference flat, be able of on-site testing, etc, it plays an important role in large flat reflective mirror’s manufacturing, especially the high accuracy testing of low order aberrations. The PSS system measures directly the slope information of the tested flat surface. Aimed at the unique requirement of M3MP, which is the prototype mirror of the tertiary mirror in TMT (Thirty Meter Telescope) project, this paper analyzed the slope distribution of low order aberrations, power and astigmatism, which is very important in the manufacturing process of M3MP. Then the sample route lines of PSS are reorganized and new data process algorism is implemented. All this work is done to improve PSS’s measure sensitivity of power and astigmatism, for guiding the manufacturing process of M3MP.
M3M (Mirror 3 Mirror) of TMT (Thirty Meter Telescope) project is a 3.5m×2.5m×0.1m solid flat elliptical mirror. M3MP is a 1/4 prototype of M3M serving as a pathfinder for M3M. Fabrication and testing of M3MP were carried out based on planned sketch for M3M established in the past 2 years. Technology including polishing strategy, on site vertical Fizeau sub-aperture interfere test, scanning pentaprism system and dual-supporting system were tested in the fabrication of M3MP. This paper give a brief introduction of the work on M3MP and some of results.
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.
The Secondary Mirror System (M2S) and Tertiary Mirror System (M3S) of the Thirty Meter Telescope (TMT) consist of
passively mounted mirrors supported in kinematic cell assemblies that are moved during telescope tracking to counteract
effects of changing zenith angle and thermal gradients within the telescope structure. TMT is concerned that the
requirements for pointing jitter during Adaptive Optics tracking for the M2 and M3 Systems are very challenging with a
risk of requiring complex stabilization systems for compliance. Both systems were researched to determine whether
similar un-stabilized hardware exists that can meet the TMT jitter requirements. Tests using representative TMT
tracking motions were then performed to measure jitter on similar existing hardware. The results of these hardware tests
have been analyzed. Test results, remaining risk assessment and further testing plans are presented.
The Terrestrial Planet Finder (TPF) Coronagraph study involves exploring the technologies that enable a coronagraph-style instrument to image and characterize earth-like planets orbiting nearby stars. Test beds have been developed to demonstrate the emerging technologies needed for this effort and an architecture study has resulted in designs of a facility that will provide the environment needed for the technology to function in this role. A broad community of participants is involved in this work through studies, analyses, fabrication of components, and participation in the design effort. The scope of activities - both on the technology side and on the architecture study side - will be presented in this paper. The status and the future plans of the activities will be reviewed.
The Galaxy Evolution Explorer is an orbiting space telescope that will collect information on star formation by observing galaxies and stars in ultraviolet wavelengths. The optical bench supporting detectors and related optical components used an interesting and unusual passive thermal compensation technique to accommodate thermally-induced focal length changes in the optical system. The proposed paper will describe the optical bench thermal compensation design including concept, analysis, assembly and testing results.
This paper and oral presentation will describe the technology studies, the testbeds, and the architecture studies that will enhance the understanding and viability of a Terrestrial Planet Finder Coronagraph.
Topics to be described fall in two categories: technology development and coronagraph mission design. The focus of the paper will be explanation of the tasks, their organization and current status.
The 2003 mission to Mars includes two Rovers, which will land on the Martian surface. Each Rover carries 9 cameras of 4 different designs. In addition, one similar camera is mounted to each lander assembly to monitor the descent and provide information for firing the control jets during landing. This paper will discuss the mechanical systems design of the cameras, including fabrication tolerances of the lenses, thermal issues, radiation shielding, planetary protection, detector mounting, electronics, the modularity achieved, and how the 10 different locations were accommodated on the very tight real estate of the Rovers and Landers.
The Multi-Angle Imaging Spectro-Radiometer is a push-broom instrument using nine cameras to collect data at nine different angles through the atmosphere. The science goals are to monitor global atmospheric particulates, cloud movements, and vegetative changes. The camera optomechanical requirements were: to operate within specification over a temperature range of 0C to 10C; to survive a temperature range of -40 degrees C to 80 degrees C; to survive launch loads and on-orbit radiation; to be non-contaminating both to itself and to other instruments; and to remain aligned through the mission. Each camera has its own lens, detector, and thermal control. The lenses are refractive; thus passive thermal focus compensation and maintaining lens positioning and centering were dominant issues. Because of the number of cameras, modularity was stressed in the design.
The design of an Earth remote sensing sensor, such as the multi-angle imaging spectroradiometer (MISR), begins with a set of science requirements that determine a set of instrument specifications. It is required that the sensor meet these specifications across the image field, over a range of sensor operating temperatures, and throughout mission life. In addition, data quality must be maintained irrespective of bright objects, such as clouds, within the scene, or out-of-field glint sources. During the design phase of MISR, many refinements to the conceptual design have been made to insure that these performance criteria are met. These design considerations are the focus of this paper. Spectral stability with field angle, scene polarization insensitivity, and UV exposure hardness have, for example, been enabled through a telecentric optical design, a Gaussian shaped filter spectral profile used in conjunction with a Lyot depolarizer, and contamination prevention through consideration of material choices and handling procedures. Spectral, radiometric, and MTF stability of the instrument assures the scientific community that MISR imagery can be used for highly accurate aerosol, bi-directional reflectance distribution function (BRDF), and cloud studies.
The multi-angle imaging spectroradiometer (MISR) instrument is currently under development for flight on the first earth observing system platform, EOS-AM1, to be launched in 1998. The instrument will obtain global multi-angle imagery at nine separate view angles, using a separate charge-coupled-device pushbroom camera at each angle. Images will be obtained at 443, 555, 670, and 865 nm with spatial sampling, selectable in-flight, ranging from 275 m to 2.2 km. Data from the instrument will be used to retrieve the optical properties of tropospheric aerosols over land and ocean, to study the bidirectional reflectance properties of the Earth's surface and clouds, and to measure terrain topography and cloud heights. This paper reviews the MISR science objectives, presents an update to some of the instrument design parameters, and discusses the status of the instrument design and development. Test results from a recently built `brassboard' prototype camera are discussed.