This is just a brief update to yesterday's post to add a few sentences that Lou wanted to hold until JAXA had had a chance to issue an official statement. According to the official statement, (posted here in Japanese), it seems that the first stage of sail deployment, in which the tip masses drag the accordion-folded sails out to their greatest possible extent, has been successfully completed. All that remains is to release the four retaining bars which will allow the sails to unfold and assume the final square shape. But, the update goes on to say, they had some concerns that caused them to decide to delay deployment until at least Tuesday night Japan time.
Lou explained in the coda to yesterday's update: "Most, but not all, of the data from the first stage appears to indicate that the deployment is going as planned. About 4-5 meters of the edges have been deployed. But there is some uncertainty and ambiguity in some of the deployment measurements. The team wants to run more simulations and analysis before initiating the final stage. The uncertainty relates to whether the whole configuration is deploying symmetrically and stably. They will run some more simulations and expect to schedule their final stage of deployment for Tuesday night Japanese time."
Apart from these concerns, however, the spacecraft's health remains excellent.