Hello Jim, N8OQ. Thanks for your very valuable reply.

Because it has the effect of the atmosphere density, I think that the re-entry into the earth's atmosphere of ARISSat-1 becomes really earlier than April 9, 2011.

I added your this reply under the following my URL,

http://www.ne.jp/asahi/hamradio/je9pel/arissat5.htm

Thank you.

JE9PEL, Mineo Wakita