Investigation On Feasibility Of New Spin Control Method For Spinning Solar Sail

Paper number

IAC-07-C1.8.04

Author

Mr. Munetaka Kashiwa, University of Tokyo, Japan

Coauthor

Prof. Junjiro Onoda, Japan Aerospace Exploration Agency (JAXA)/ISAS, Japan

Year

2007

Abstract

A spinning solar sail has proposed as a type of various proposed solar sails. The spinning solar sail deploys a huge membrane to reflect the photon from the sun and maintains the deployed shape of the reflector membrane by utilizing centrifugal force. Thus, It can reduce its total weight much than solar sails using support structures by reducing weights of support structures. However, it is very difficult for the spinning solar sail to control the spin rate because very large angular momentum is required to change the spin rate because of the huge deployed membrane. Conventional spin control devices, for example gas thrusters or wheels, need very large and heavy device to change such large angular momentum.

The authors have proposed a new spin control method for the spinning solar sail. In the proposed method, many piezoelectric films are attached to the membrane. By giving electric voltage to the piezoelectric films, curved surfaces are created around the piezoelectric films. Two kinds of coatings with different reflectivity are introduced to each side of the curvature, and the unbalance of the solar pressure in circumferential direction is obtained. This unbalance of the solar pressure caused a spin torque for the spinning solar sail. Thus, by controlling the magnitude or polarity of the voltage for the piezoelectric films, the magnitude or direction of the spin torque can be controlled. The authors have investigated the feasibility of the proposed method utilizing the simple analytical model. However, in this simple model, the membrane was assumed to be elastica and the cross-sectional deformation was only considered. The deformation of the membrane in the radial direction and the effects of the wrinkling were neglected.

In this paper, the finite element analysis utilizing a detailed model for the membrane is performed. Since the analysis is conducted in the three-dimensional model, the membrane can deform in the radial direction. In addition, the effects of the wrinkling on the membrane are also taken into account by conducting the buckling analysis. Utilizing this detailed membrane model, the quantitative investigation of the effects of the radial deformation and the wrinkling on the spin torque is described. Moreover, the relation between the control torque and the circumferential stress of the membrane is also described. Through these investigations, the feasibility of the proposed method is discussed.

Abstract document

IAC-07-C1.8.04.pdf

Manuscript document

IAC-07-C1.8.04.pdf (🔒 authorized access only).

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