M. Yu. Arkhipov – Ph.D. (Eng.), Senior Research Scientist,

P.N. Lebedev Physical Institute of the Russian Academy of Sciences

E-mail: markhipov@asc.rssi.ru

E. S. Golubev – Leading Engineer,

P.N. Lebedev Physical Institute of the Russian Academy of Sciences

S. A. Kozlov – Head of the Electronics Department,

JSC “Applied Mechanics”

A. O. Lyakhovec – Leading Software Engineer,

P.N. Lebedev Physical Institute of the Russian Academy of Sciences

E. K. Filina – Engineer,

P.N. Lebedev Physical Institute of the Russian Academy of Sciences

A. V. Yusov – Chief Designer, OOO “Applied Mechanics”

The interest of modern astrophysics to the space investigation in the millimeter and submillimeter wavelength ranges necessitates the development of large adaptive mirrors. The paper presents the results of the experimental research on adaptation of a large panel of a millimeter-wave space telescope. The adaptation system of the panel consists of three actuator nodes, each providing three degrees of freedom. The tolerance of the adaptation system must not exceed 1 µm. Specifics of the operation conditions such as cooling the panel down to ultra-low temperatures (below 10 K), high launch loads and restrictions on the weight of the panel increase the complexity of the adaptation problem. The aim of present research is to analyze the resolution (minimum stable step) of the actuator, repeatability at large displacements, kinematics of the panel and the effect of the elastic joints on the accuracy of the panel’s reflecting surface. For this purpose, the experimental setup was developed and panel displacements due to actuator performance were measured. The setup consists of a 1050x1450 mm parabolic panel mounted on a rigid frame with three actuator nodes. Each actuator node comprises one degree-of-freedom and two-degrees-of-freedom elastic flexures. One of the nodes includes an electromechanical cryogenic actuator, whereas the other two nodes use stiffness-dimensional imitators. The Zeiss Prismo Ultra coordinate measuring machine and four micrometers were used as measuring tools. The experiment demonstrated high resolution of panel displacement (less than 1 μm) and repeatability (the maximum error achieved is 1,2 μm). The analysis of the panel kinematics showed high correspondence between the mathematical model and measurement data with an accuracy of 3 μm. It was also shown that the elastic joints in the actuator nodes slightly affect the accuracy of the panel’s reflecting surface both during installation of the system and panel adaptation (less than 1 μm).

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