Vibroacoustic launch analysis and alleviation of lightweight, active mirrors

Lightweight, active, silicon carbide mirrors can increase the capability of space-based optical systems. However, launch survival is a serious concern for such systems, with the vibrations and acoustics from launch threatening to damage the optics. Therefore, a dynamic, state- space launch model has been developed with which one can quickly analyze the survival probability of many designs and also directly analyze launch load alleviation techniques. This paper discusses the launch model from which launch stress and survival probability are obtained, as well as launch load alleviation techniques that may increase the probability of launch survival. Three launch load alleviation techniques are presented and analyzed: whole spacecraft isolation, passive shunt circuits using the existing embedded actuators, and active damping using the existing ac- tuators. All of the techniques reduce the launch stress, but at the expense of mass and complexity. The launch model allows for early identification of lightweight, active mirror designs which will survive launch, and the alleviation techniques expand the feasible design space by decreasing the launch stress and increasing the probability of launch survival. C 2011

[1]  Howard A. MacEwen.  Separation of functions as an approach to development of large space telescope mirrors , 2004, SPIE Optics + Photonics.

[2]  Scott Alan Uebelhart,et al.  Non-deterministic design and analysis of parameterized optical structures during conceptual design , 2006 .

[3]  H. Saunders.  Book Reviews : NUMERICAL METHODS IN FINITE ELEMENT ANALYSIS K.-J. Bathe and E.L. Wilson Prentice-Hall, Inc, Englewood Cliffs, NJ , 1978 .

[4]  R.H.S. Riordan,et al.  Simulated inductors using differential amplifiers , 1967 .

[5]  Lucy Elizabeth Cohan,et al.  Integrated modeling and design of lightweight, active mirrors for launch survival and on-orbit performance , 2010 .

[6]  Paul S. Wilke,et al.  Protecting Satellites from the Dynamics of the Launch Environment , 2003 .

[7]  Witold Kowbel,et al.  SiC-SiC composites optics for UV applications , 2007, SPIE Optical Engineering + Applications.

[8]  David W. Miller,et al.  Vibroacoustic analysis and optimization of lightweight silicon carbide mirrors , 2009, Optical Engineering + Applications.

[9]  Joseph R. Maly,et al.  CASPAR: Low-Cost, Dual-Manifest Payload Adapter for Minotaur IV , 2005 .

[10]  David W. Miller,et al.  Integrated modeling for determining launch survival and limitations of actuated lightweight mirrors , 2008, Astronomical Telescopes + Instrumentation.

[11]  Paul S. Wilke,et al.  Whole-spacecraft passive launch isolation , 1997 .

[12]  Nesbitt W. Hagood,et al.  Damping of structural vibrations with piezoelectric materials and passive electrical networks , 1991 .

[13]  James B. Breckinridge,et al.  UV/Optical/IR Space Telescopes: Innovative Technologies and Concepts III , 2004 .

[14]  A. Winsor.  Sampling techniques. , 2000, Nursing times.

[15]  Andrew J. Fleming,et al.  Synthetic impedance for implementation of piezoelectric shunt-damping circuits , 2000 .

[16]  K. Bathe.  Finite Element Procedures , 1995 .

[17]  T. K. Caughey,et al.  On the stability problem caused by finite actuator dynamics in the collocated control of large space structures , 1985 .

[18]  Richard A. Brown,et al.  Introduction to random signals and applied kalman filtering (3rd ed , 2012 .

[19]  J. L. Fanson,et al.  Positive position feedback control for large space structures , 1987 .

[20]  M. A. Ealcy.  Large optics in the 21st century: a transition from discrete manufacturing to highly integrated techniques , 2003, 2003 IEEE Aerospace Conference Proceedings (Cat. No.03TH8652).

[21]  Paul S. Wilke,et al.  Whole-Spacecraft Passive Launch Isolation , 1998 .

[22]  Mark A. Ealey.  Fully active telescope , 2004, SPIE Optics + Photonics.