Yuichi Tsuda

Generalized Attitude Model for Spinning Solar Sail Spacecraft

An attitude model for a general spinning solar sail spacecraft under the influence of solar radiation pressure is presented. This model, called “Generalized Spinning Sail Model”, can be applied to realistic sails with nonflat surfaces that have nonuniform optical properties. The unique behaviors predicted by the generalized spinning sail model are verified by actual operation of the Japanese spinning solar sail spacecraft IKAROS. It is shown how imperfections in the sail surface affect the attitude motion of spinning sails, and a compact mathematical model that can precisely reproduce the spin-averaged motion of the spinning sails is derived. The stability conditions and a reduced model that preserves the key characteristics of the generalized spinning sail model are also derived to reveal the unique properties of the attitude behavior of spinning sails.

How IKAROS Shape is Designed: Attitude Stability of Spinning Solar Sail

This paper discusses the attitude stability criteria for spinning spacecraft equipped with large flexible membrane, such as solar sail. One actual realization of such a configuration is IKAROS, which is the world-first interplanetary solar sail spacecraft launched by JAXA in 2010. The authors previously derived stability criteria for spinning sail craft. This paper revisits the stability criteria of spinning solar sail spacecraft, and shows how it has been applied to the practical design of the IKAROS spacecraft configuration. The validity of the stability criteria is then evaluated by some numerical simulations and flight data of IKAROS.

Design Criteria of Spinning Solar Sail Surface Based on Attitude Dynamics

This paper describes design criteria for sail surface quality derived from requirements about attitude dynamics of spinning solar sail spacecraft. The method has been developed by an experience of the Japanese interplanetary solar sail mission IKAROS. The authors derived, in their previous work, a combination of a generalized spinning attitude model and a finite element model-based sail deformation analysis method to directly relate the sail surface wrinkling and the attitude disturbance via solar radiation pressure effect. Based on this work, this paper attempts to derive design criteria for the sail surface quality, which is useful for the mission analysis and the quality control in sail production. Specifically, this paper provides an acceptable deformation level as a function of scale length for given attitude stability requirements against the solar radiation pressure disturbance, which is then compared and verified by the post-flight analysis of IKAROS.