Solar and Thermal Radiation Models and Flight Evaluation for IKAROS Solar Sail

This paper gives a detailed evaluation of the solar and thermal radiation accelerations acting on the IKAROS spacecraft consisting of a solar sail and a central body during its operational mission from June to December2010. In particular, the predicted temperatures are compared with actual in-flight measurements on the sail membrane and on the body. The results show good correspondences in most cases, but a few appreciable deviations have been observed as well. The simulation results indicate that the magnitude of the thermal radiation perturbations on the solar sail trajectory is below 1% of those induced by the solar radiation. The accelerations caused by the thermal radiation turn out to be insignificant because their magnitudes are within the range of uncertainty of the accelerations induced by the solar radiation forces.