that was strange....it just faded away...
I'm in Michigan, and tonight's ISS fly-by was scheduled for 8:18:56 PM, and I was outside to see it. As it came into view, it got brighter and brighter. Soon enough it was directly overhead and very bright. Then, within a few seconds, it just faded to nothing...gone. I've never seen it do that before. Does anyone know why it does that? Did it do something to fade from view entirely? Plz advz. It's gonna fly over all this week thru Sunday.
rongermanjr – Wed, 2010 – 10 – 27 20:39
ISS visible
There are a couple of things for the ISS to be visible.
The observer has to be in darkness or near darkness and the ISS has to be in sunlight.
And the latter is why I believe it "faded" out. The ISS would have essentially been shadowed by the earth at just that time when it faded out.
ISS Visibility
You are most substantially correct.
If you are not using real-time orbital simulation software (STSPlus is old DOS stuff, but it is actually used by NASA and was used aboard the MIR) the sudden passage of a 'visible' spacecraft into eclipse will lead to some very puzzling "disappearances". Trying to imagine the three-dimensional dynamics of a spacecraft orbit, combined with the earths sun-shadow location, is difficult enough to make your head hurt.
I believe that STSPlus, though the author is deceased, is still available on the 'net, due to the commendable efforts of some individuals that understand the importance of the program, and wish to keep it viable. BTW, make sure that you find and download the higher-resolution map data files. The default map is substantially crude. I don't remember the details of the files--you will need to read through the substantual user document to get it right.
There are other share-ware programs available, even in glossy Windows versions: it's just that STSPlus is all I have ever felt a need for, including to providing realtime antenna azimuth and elevation data via serial data output. If you are good enough with hardware and software, you can automatically point a dual-rotor antenna array bang-on the target spacecraft. Even a Basic Stamp controller can handle a good part of the job.