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Facilities
SSG has four facilities – three in Massachusetts and one in California. Our corporate offices and engineering facility, located in Wilmington, Massachusetts, supports design, fabrication, optical alignment/test, and optical fabrication within a modern 65,000 square foot building. Tinsley Laboratories, located in Richmond, California, is a state of the art 50,000 square foot facility that houses a modern optical fabrication capability. SSGPO’s Ceramics Division and Optics Division are both located in Massachusetts.
Main Facility – Wilmington
SSG’s main facility in Wilmington, Massachusetts has all the facilities needed for design, fabrication, test, and alignment of advanced optical systems for aerospace and commercial uses.
Design Facilities and Equipment
SSG’s computer hardware includes primarily IBM PC compatible computers, with many high capacity machines available for optical and mechanical design/analysis, system control, and data reduction. SSG's main optical design/analysis program is CODE V. Optical engineering tasks also utilize ZEMAX, OSLO, and APART. SSGPO has written in-house translators to transfer the optical design information into file formats compatible with our mechanical design effort. SSGPO uses AutoCAD-based design software (AUTOCAD 2002, Mechanical Desktop, and INVENTOR) to define the mechanical details of the mirrors, mounting interfaces, supporting structure, baffles, and sub-assemblies. SSGPO performs detailed structural and thermal analyses by using NASTRAN, STARDYNE, TSS, TD, TAS and SINDA. This approach gives SSG the advanced capability of predicting the effects of random and prescribed stress environments, dynamic and static thermal loading, thermal gradient induced stresses, and thermally induced stresses.
Fabrication Facilities and Equipment
SSGPO has complete facilities for the prototyping, development and testing of telescope, and pointing/tracking components and subsystems. The company has > 65,000 sq. ft. of manufacturing, laboratory, and office space. Class 100 & 10,000 clean rooms are available for assembly and testing. The clean room areas contain air-bearing tables and interferometric metrology equipment for sub-assembly alignment and testing. SSG’s test area contains visible and IR straylight test stations, vacuum, and cryogenic test facilities for optics up to 24" in diameter. Vibrational modes of components and assemblies can be verified with an in-house resonant frequency test station. Standard optical and electrical laboratory test equipment, such as collimator, theodolites, radiation sources, test detectors, preamplifiers, oscilloscopes, microscopes, and normal laboratory equipment is available.
SSG has its own Optical Fabrication Division at the Wilmington facility which specializes in the polishing of small to moderately large (up to 1 meter) off-axis, low scatter aspheric optical components for use in space environments to cryogenic temperatures. SSG/Optics Division has its own in-house plating facility for electroless nickel and electroplated gold, along with state-of-the-art low scatter finishing facilities. The polishing facilities at SSG/Optics Division have produced high quality mirrors in aluminum, nickel, beryllium, silicon carbide, and glass. SSG’s inspection departments have several 3-axis coordinate measuring machines for incoming and in-process inspection of the optical elements and opto-mechanical components. Computer software has been developed to translate the CMM data into a best-fit aspheric curve for verification of the surface generation. Testing of the optical parameters is performed using Laser Unequal Path Interferometry (LUPI), commercial Fizeau interferometers, and specialized test set-ups.
Pictures of SSG’s Main Facility:
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SSG Clean Room
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Straylight Rejection Test Source
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Cryogenic Test Chamber
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Aspheric Polishing
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Coordinate Measuring Machine Inspection
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Interferometric Alignment
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Tinsley, Richmond California
SSG has recently acquired the government contract supported portion of Tinsley Laboratories. Tinsley brings a 77-year tradition of high precision optical fabrication to SSG. Their modern optical fabrication capabilities include high accuracy, deterministic grinding and computer controlled optical surfacing (CCOS), and precision profilometry and interferometry. The CCOS process has been developed and refined over a 25-year period. The following outlines their present expertise:
- Very high accuracy, deterministic aspheric Computer Controlled Optical Surfacing (CCOS)
- Iterative small tool polishing
- Sizes to 1.5 meters (1.2 meters for off-axis)
- Compatible with all material surface types; Al, Ni, Be SiC, Si, Glass & Refractive Visible & IR Lenses
- On axis and off axis optical segments
- Fast f-numbers
- <0.01 waves rms visible
- Production rates: 100’s high quality aspherics optics/month
- Large planetary polishers for flat surface up to 1 meter
- Diamond turning to 40 inch on axis mirror & 16 inch off axis segment
- Precision machining of very lightweight substrates
- Unique position in Bare Be mirrors (size to 1.2 meters)
- High rate production capacity (17 CCOS machines)
- Precision metrology including profilometry and interferometry to <0.005 waves rms in visible
Ceramics Division
SSG’s Ceramics Division is dedicated to the fabrication of ceramic and composite versions of SiC. The Ceramics Division facility has approximately 6,000 sq. ft. of manufacturing space which contains all of the equipment and tooling required for SiC fabrication.
Pictures of Ceramics Division:
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Ceramics Division – Interior
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SiC Furnace Area
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SiC Furnace – Front View
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SiC Furnace – Side View
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Plating Facility
SSG maintains a plating facility located in Georgetown, Massachusetts. Plating of our metal optical substrates – aluminum and beryllium – is applied in a controlled environment. Our plating capability includes electroless nickel-plating for mirrors up to 50-inch diameter and electroplated gold up to 24-inch diameter.
Biographies of Senior SSG/Tinsley Management
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SSG’s Mission Statement
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Brief history of SSG and Tinsley
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Overview of our R&D and Manufacturing facilities
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