A new astrophotography challenge

Taken through the 20 inch scope, the ISS (space station) passed first 350 miles from the observatory, then went round the earth and passed 1000 miles from the observatory then faded into the earth's shadow (night). I had to chase it, but I got pics both times round with my Canon. I made them into this mosaic that puts the images much closer together The second time round (bottom), it was at a lower altitude in the sky. It moves at something like 20000 mph! I'm well chuffed just seeing some detail. I guessed an exposure of 1/800" at ISO 1600. Apparently the software we have can be programmed for tracking satellites. Next time the ISS shows its face in the evening, I'd like to give imaging it a proper go. The tracking accuracy involved in getting the ISS on our Imaging source camera's tiny chip with a barlow lens might well out stretch our capabilities.