The Supporting Of Thin-film Primary Mirror Based On Tape Springs And Design And Testing Of Self-deploying Structure

At present, the deployment mechanism in the aviation and aerospace fields has been widely used. Since the small launch size and the low launch costs of the deployable telescope, it has become an important area of research scholars. A self-deploying tape spring structure is designed in the thesis in which photon sieve membrane is used as the diffractive imaging component. The structure is assembled on the small satellite, and it takes up small volume. The structure is under compression and tape springs are under rollable state before the satellite launches. Tape springs deploy at the same time and the structure reaches the full deployment state when the satellite reaches its orbit. This self-deployable diffraction telescope system with the features of large caliber, high-resolution, lightweight structure, space deployable, low tolerance, easy replication, has good prospects.Firstly, the three-dimensional model based on tape springs has been established, and operating principle has been analyzed. Strain energy of tape springs have been calculate, and the subtended angle and the thickness of the tape springs have been chosen reasonably. Statics analysis is proceeded for thin-film primary mirror,and the optical path length can less than one-tenth wavelength, with the maximum out-of-plane deformation of the thin-film primary mirror 3.26 ?m, which satisfies the accuracy requirements. Modal analysis is conducted for the structure, and the fundamental frequency is 17.3Hz,which can estimate dynamic characteristics of the self-deploying structure. It is shown that the tape springs are the dynamical weakest part, and it might provide the basis for improvements.A method to measure the repositioning resolution of the self-deployable structure is raised, which can detect the six degrees of freedom of the primary mirror. The measuring system is based on position sensitive detector(PSD), which consists of three semiconductor lasers, three small mirrors, three PSD sensors using ray tracing method to derive the equations between the six degrees of freedom of the primary mirror and PSD output values.Finally, the compression and expansionexperiment were conducted to the mechanism, and the effect of its expansion is observed. Six degrees of freedom of the primary mirror is measured. It is verified that the size of the offset amount meets the requirements of diffraction imaging system.