Steve, There is a very nice scheduling program to be found at: http://www.cs.rit.edu/~cjh9783/programs/satsched.php I have not a user of AO-27, yet, so cannot confirm where it is accurate, as it depends on getting an update file from the AO-27 site. Perhaps someone who is knowledgeable can comment on whether it is current? Alan WA4SCA