On July 13, 2016, ISAS/JAXA conducted an unfolding demonstration of an actual size solar power sail to evaluate its manufacturing accuracy and stick mounted devices. The demonstration was opened to the public, and more than 250 general public people visited to observe the demonstration. The demonstration completed successfully, and ISAS researchers will inspect the data in detail.

ISAS/JAXA is developing and testing components to realize a solar power sail for exploration of the Jupiter trojans. The solar power sail is one of the most important components. ISAS researchers had manufactured an actual size sail (1/4 of the whole sail, a side length of 50 meter) from 2014 to 2015.

Time lapse of the unfolding demonstration [You Tube]

Fig. 1: Ready to unfold the sail. On Matsumoto's mark "Three two one, GO!" (15:53 JST)

Fig.2: Gently and smoothly, all the project members unfolded the sail together. Prof. Kawaguchi, the previous project manger of HAYABUSA mission, also jointed. (15:57 JST)

Fig.3: Unfolding was completed. How huge the sail with the side length 50 meter! The sail of IKAROS (Small Solar Power Sail Demonstrator) was also unfolded for comparison. (18:03 JST)

Fig.4: Next, the work changed to attach harness transmitting electric power. The members kept doing delicate work. (19:57 JST)

Fig. 5: Almost the end of the demonstration. The members slowly and carefully folded the sail. (21:14 JST)