Abstract
Japanese spin-type solar power sail IKAROS was launched in May 21st 2010 by JAXA, and the 20m-sized sail membrane was successfully deployed in June 2010. The deployment was achieved through two stages. In the first stage, a part of the membrane is unwrapped quasi-statically from the cylindrical spacecraft. In the second stage, the whole membrane is deployed dynamically from the spacecraft. During the design and development process of the sail membrane structure in last three years, the numerical simulation of the deployment dynamics had been one of the most important issues. In this paper, the pre-flight prediction of the deployment behavior in the second stage is summarized, and the flight data is compared with the numerical simulation.
