Design, modeling and experimental investigation of a novel solar sail with high area-to-mass ratios for efficient solar sailing

Solar sailing is a promising propellant-free approach to propelling spacecraft in space. However, the propelling efficiency of conventional solar sail spacecraft is limited by their area-to-mass ratios. This paper proposes a novel design of micro solar sails with area-to-mass ratios above 100 m2/kg for next-generation chip-scale spacecraft. Bilayer thin films developed by Microelectromechanical Systems (MEMS) technologies were patterned into grid microstructures, and theoretical analysis of a sail prototype was conducted. The electro-thermal and thermo-mechanical models of the solar sail in geospace were established by taking effects of Joule heating, solar radiation, and thermal re-emission into consideration, enabling rapid prediction of its three-dimensional (3-D) reconfiguration from the as-released two-dimensional (2-D) microstructure. Adjustment of the ChipSail’s acceleration arising from the sail’s morphing was also analytically modeled. Fabrication and characterization of the sail prototype made of multiple Al/Ni50Ti50 bilayer beams were accomplished. In-situ SEM imaging of the sail prototype in vacuum chamber witnessed an active and continuous 3-D reconfiguration under Joule heating, and over 90° deformation was detected by applying a DC voltage of 0.078 V. Theoretical and experimental work on the solar sail with at least 10 times higher area-to-mass ratios than conventional ones will lay a solid foundation for efficient solar sailing.