In order to produce an instrument or sensor design in the face of demanding environmental constraints of a spaceborne system, an integrated approach to sensor design has been developed that incorporates design tools for: optical design, mechanical design, structural, stray light and thermal analysis. This integrated approach can be extended to the entire payload design and its increased constraints.
At the Advanced Technology Center of Lockheed Martin Missiles and Space, we have created an integrated optical, mechanical, thermal and structural design and analysis program called `Optics Plus'. This program is a rapid and accurate system for mechanical design and analysis of optical systems, including thermal, stray light and structural properties. Accurate cost and performance balancing trades are possible in very short time frames, thereby reducing overall costs previously much greater. There are three factors in its success: (1) An Integrated Team of analysists, domain experts and software experts that design, build and use the tool, (2) Integrated Tools that include OPTIMA, IDEAS, ASAP Plus, MSAT, and TMG, and (3) Outstanding Support from the laboratories broad expertise in optics, thermal and structural analysis. This paper will describe how the integrated system operates and a flow diagram will spell out the nodes of program interactions. The resultant will be demonstrated with several examples of cryogenic instruments.
This paper extends the previously reported results of cryogenic optical testing (SPIE Volume 2543, 1995) by including the results of further reduction of the test data for the 170-mm-diameter silicon carbide mirror and the 178-mm- diameter aluminum mirror. Both mirrors were manufactured by the Vavilov State Optical Institute, St. Petersburg, Russia, for infrared applications and were loaned to LMMS for these tests. Optical tests were performed in the Lockheed Martin cryogenic optical test facility at liquid helium temperatures, using a Zygo Mark II interferometer. The initial surface figures were 0.18 waves and 0.08 waves for the aluminum and the SiC mirrors, respectively, with figure error being given as rms wavefront error at 0.6328-micron wavelength at room temperature. It was found that the maximum change in shape after cooling was between 0.007 and 0.036 waves for the SiC mirror and between 0.017 and 0.062 waves for the aluminum mirror.
This paper presents the results of interferometric tests of two silicon carbide mirrors tested at room temperature and 6 K. The first mirror has a spherical f/1.73 surface, a diameter of 170 mm, and is of solid, plano-concave construction. The other mirror, a plano measuring 308 mm by 210 mm, is of lightweighted, closed-back construction. The mirrors were manufactured by the Vavilov State Optical Institute, St. Petersburg, Russia, and were loaned to Lockheed for these tests. Optical tests on both mirrors were performed using the Lockheed cryogenic optical test facility at liquid helium temperature and a Zygo Mark II interferometer. There was no change in the surface figure of the mirrors, within the test uncertainty of approximately plus or minus 0.02 waves at 0.6328-micrometer wavelength.