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Design of All-SiC Lightweight Secondary and Tertiary Mirrors for Use in Spaceborne Telescopes

  • Bae, Jong-In (Department of Nanoscience and Technology, Jeonbuk National University) ;
  • Lee, Haeng-Bok (Electro-optics Department, Agency for Defense Development) ;
  • Kim, Jeong-Won (Material Development Division, Orange E&C) ;
  • Kim, Myung-Whun (Department of Nanoscience and Technology, Jeonbuk National University)
  • Received : 2021.10.11
  • Accepted : 2021.11.17
  • Published : 2022.02.25

Abstract

We report on the design of the secondary and the tertiary mirrors used in lightweight assemblies made entirely of silicon carbide (SiC). The essential design points are weight reduction within the acceptable deformation of the mirror surface by gravity release, temperature change, and vibration during or after space launch. To find a design that achieves the target requirements, we established finite element models for various candidate designs and subjected each one to wave front error analyses along gravity directions and in operation temperatures. We also calculated the natural frequencies of the candidate assemblies. Our study suggested that a triangular cell with bipod flexure support can satisfy the target weight within the requirements.

Keywords

Acknowledgement

National University Development Project of Jeonbuk National University in 2020.

References

  1. H. P. Stahl, "Mirror technology roadmap for optical/IR/FIR space telescopes," Proc. SPIE 6265, 626504 (2006).
  2. J. L. Robichaud, "SiC optics for EUV, UV, and visible space missions," Proc. SPIE 4854, 39-49 (2003).
  3. I. A. Palusinski and I. Ghozeil, "Space qualification of silicon carbide for mirror applications: progress and future objectives," Proc. SPIE 6289, 628903 (2006).
  4. R. A. Paquin and D. R. McCarter, "Why silicon for telescope mirrors and structures?," Proc. SPIE 7425, 74250E (2009).
  5. J. Robichaud, J. J. Guregian, and M. Schwalm, "SiC optics for earth observing applications," Proc. SPIE 5151, 53-62 (2003).
  6. I. A. Palusinski and I. Ghozeil, "Developing SiC for optical system applications," Proc. SPIE 5524, 14-20 (2004).
  7. E. Sein, Y. Toulemont, F. Safa, M. Duran, P. Deny, D. de Chambure, T. Passvogel, and G. L. Pilbratt, "A Φ3.5 m SiC telescope for Herschel mission," Proc. SPIE 4850, 4797-4805 (2003).
  8. I. K. Moon, H.-S. Yang, and Y. W. Lee, "Design and development of large SiC mirror for spaceborne application," Proc. SPIE 11100, 111000J (2019).
  9. M. R. Krodel, M. J. Collon, R. Graue, and D. Kampf, "Cesic and silicon: a perfect combination for high performance applications," Proc. SPIE 6666, 66660M (2007).
  10. S. E. Kendrick and H. P. Stahl, "Large aperture space telescope mirror fabrication trades," Proc. SPIE 7010, 70102G (2008).
  11. H.-B. Lee, J.-Y. Suk, and J.-I. Bae, "Trade study of all-SiC lightweight primary mirror and metering structure for space-borne telescope," Proc. SPIE 9574, 95740D (2015).
  12. H.-B. Lee and R. G. Cobb, "Design of lightweight primary mirror and metering structure for spaceborne telescope," Proc. SPIE 6049, 6049P (2005).
  13. J. W. Pepi, "Analytical predictions for lightweight optics in a gravitational and thermal environment," Proc. SPIE 0748, 172-179 (1987).
  14. W. P. Barnes, "Optimal design of cored mirror structures," Appl. Opt. 8, 1191-1196 (1969). https://doi.org/10.1364/AO.8.001191
  15. W. P. Barnes, "Hexagonal vs triangular core lightweight mirror structures," Appl. Opt. 11, 2748-2751 (1972). https://doi.org/10.1364/AO.11.002748
  16. W. C. Young, Roark's Formulas for Stress and Strain, 6th ed., (McGraw-hill, NY, USA. 1989).
  17. K. B. Doyle, V. L. Genberg, and G. J. Michels, Integrated optomechanical analysis (SPIE Press, USA. 2002), Vol. TT58.
  18. R. Williams and H. F. Brinson, "Circular plate on multipoint supports," J. Franklin Inst. 297, 429-447 (1974). https://doi.org/10.1016/0016-0032(74)90120-3