Thank you very much! With the files at celestrak.com it works very well. However, I'm not able to process the gz files from Space Track. Does anyone have any experience about how precise the Iridium flare predictions are? I've tried some of them, but compared to heavens-above.com they seem to be off by half a minute(possibly they've got more recent elements). Maybe I'll observe some of them the next couple of weeks to see which one works best (usually heavens-above is very precise). @Gennady: I found the quicksat program at http://www.io.com/~mmccants/programs/index.html
Clear skies, Robin
