A novel design and thermal analysis of micro solar sails for solar sailing with chip scale spacecraft

The past few decades have seen many meaningful trials on development of solar sail spacecraft with high area-to-mass ratios and thus allowing efficient, propellant-free photon propulsion. However, the restriction to bending stiffness of thin solar films has proven to be an obstacle for building solar sails with high area-to-mass ratios. This paper presents a novel design of micro solar sails for emerging lightweight chip scale spacecraft based on flexible electronics. A representative concept design of the chip scale solar sail spacecraft with area-to-mass ratios over 100 m²/kg is proposed, which enables efficient orbital transfer and attitude adjustment. To acquire large deformation for adjustment of forces, the micro solar sails consisting of bilayer beams are actuated by Joule heating. Electro-thermal analysis on the sails after deployed into space should be the prioritized and fundamental problem for following evaluation of deflection and thus change of solar radiation pressure on the reflective sails. Solar radiation, thermal reemission, and Joule heating are incorporated into the electro-thermal model for such solar sails deployed in geospace. A nonlinear second order differential equation is derived, which is solved numerically for temperature distribution across the sail. The proposed electro-thermal model is validated by finite element analysis and lays a solid foundation for the thermo-mechanical modelling, as well as flight modelling, of the chip scale spacecraft with such micro solar sails.