Measurement and Calculation of Light Pressure on Constructional Materials
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TICAL INSTRUMENTATION
Measurement and Calculation of Light Pressure on Constructional Materials A.V. Afonasenkoa, Yu. E. Geintsa, A. N. Gritsutaa, A. V. Klimkina, S. V. Latyntsevb, A. V. Ovchinnikovb, K. Yu. Osipova, I. V. Ptashnika, A. A. Solodova, *, A. M. Solodova, and E. N. Yakimovb aV.E.
Zuev Institute of Atmospheric Optics, Siberian Branch, Russian Academy of Sciences, Tomsk, 634055 Russia b JSC Information Satellite Systems, Zheleznogorsk, 662972 Russia *e-mail: [email protected] Received January 16, 2020; revised January 16, 2020; accepted February 6, 2020
Abstract—An experimental setup and experiments on measurements and calculation of light pressure on constructional materials at different light angles are presented. This calculation is necessary to determine the lighting properties of a material and the total solar pressure moment. Industrial metal-knitted textile was used as a constructional material. Metal-knitted textile is a material for large-diameter spacecraft antennas. More than 4000 experimental measurements of the transmittance and reflection coefficients of the metal-knitted textile were carried out for the calculation. Keywords: light pressure, metal-knitted textile, mesh antennas DOI: 10.1134/S1024856020040028
INTRODUCTION Flexible mesh antennas are often used to provide satellites with radio communications. They consist of parabolic reflectors with a diameter of tens of meters [1, 2] made from metal-knitted textile. The surface of such antennas may be more than 500 m2 [3]. A large satellite antenna can act as a solar sail, which gives a spacecraft an additional mechanical impulse, the magnitude of which vary depending on the spatial orientation of the spacecraft with respect to the Sun [4, 5]. The sunlight power which affects the reflector surface is comparable with the nominal thrust of satellite ion engines, which should be taken into account when designing spacecraft. The calculation of the light pressure impulse should be based on the optical characteristics of metal-knitted textile the antenna reflector is made from, including its albedo at different light angles. The characterization from direct measurements with standard spectroscopic equipment [6] is complicated by the cell structure of a metal mesh, since >80% of its surface is empty space. In addition, a cylindrical wire knitted textile is characterized by strongly anisotropic light scattering, which introduces additional difficulties in recording both transmitted and reflected radiation. The textile is “mesh in mesh” knitted, that is, a “thread” of the coarse mesh structure is a fine mesh. The material of the mesh is gold-plated molybdenum wire of a rib structure.
Two samples of the metal-knitted textile were taken for the study: eroded and noneroded. When operating in space, an antenna is eroded under the action of jets of ion engines, which correct the spacecraft trajectory; the gold coating layer of the mesh is destroyed and exfoliates from the surface. 1. EXPERIMENTAL The experimental setup (ES) includes a Bruker IFS 125HR F
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