On the Analysis of a Rotating Solar Sail

The problem of determining the transmission coefficient of thin-film materials of large-size convertible space structures depending on the value of their deformation is considered. A technique is presented for determining the transmission coefficient in the apparent and near infrared and ultraviolet ranges of lengths of electromagnetic waves depending on the value of the longitudinal strain in the uniaxial extension of the thin-film material specimen. The results of experiments with the polyethyleneterephthalate (PETPh) aluminum-backed film showed that the normal integral transmission coefficient can vary in broad limits and its significant growth begins as the longitudinal strain is greater than 10%. A numerical example shows that a decrease in the deflection of the end point of the nonideal solar sail results in a variation in the propulsive force. This, in turn, affects the ballistic parameters of the solar sail.