Voices of a Distant Star/Headscratchers


 * From the manga: after the battle at Agharta, Mikako sees Hisa and Noboru's names on the crew roster for the relief fleet. Since the FTL drive circumvents relativistic time dilation, this means that she's seeing the roster during the earth year 2048 (or somewhere around there).  Noboru was on earth when he received Mikako's message, meaning that the his fleet doesn't launch until at least around 2056.  Further, since the Lysithea is limited to speed-of-light communications, it means that the message would have had to have been sent around the earth year 2040, 7 years before the Lysithea launched.  (Dates are rough approximations)
 * As manga wasn't done by Shinkai himself, IIRC, the most probable explanation would be that mangaka simply screwed up with the dates. It's highly doubtful that Shinkai, who's known for his painstaking attention to the details (and scientific accuracy of his SF works), would do that major a mistake.