[AMSAT-BB] Two grid squares - is it possible ?

I remember seeing a web site that calculated if two grid squares were in the same footprint of a satellite.

I can not find it and would like to know if Hawaii is ever possible from FN30. I don't believe it is but hope springs eternal. It will also be useful for the EU passes on RS-44 from the East Coast USA.

Anyone have a link for this calculation ?

Thanks and 73 Frank WA2NDV FN30