ISS Flyby – August 23, 2007

I have continually been amazed by webcam photos that amateur astronomers have shot of the International Space Station and the Shuttle. I didn’t figure it was something I was equipped to do, so I just admired from a distance. Well, yesterday I ran across a photo by an individual who photographed the ISS with a Canon DSLR and I was quickly inspired to try it myself. It just so happens that I received a Telrad finder this week to replace the horrible finder I’ve been using the last three years. It also just so happens that the ISS was due to pass almost directly overhead tonight. So I got home from work this evening, installed the Telrad, prepped the telescope and camera, and waited for the space station to crest Mt. Elden. After some preliminary test shots on Jupiter and the Moon, I settled on ISO 1600 with a shutter speed of 1/1000 second. My scope doesn’t let the camera come to focus when its placed at prime focus. So I loaded the camera and T-Ring in behind my 2X barlow. Because my Canon 300D makes for an extremely lop-sided eyepiece attachment, I asked Amanda to hold onto the camera strap just in case it popped loose and fell at an unfortunate moment. I’m happy to say that didn’t happen.

The Telrad made the entire process a breeze. As soon as the ISS became visible, I sighted the Telrad a bit ahead of its path, and then snapped the shutter the moment it entered the center of the innermost bullseye. Then I moved the scope a bit more to get ahead of it and shot again. Unfortunately, just as it passed overhead, I ran into one of the tripod legs and lost several of the best seconds of its closest passage. Such is the curse of this f/8 scope on a tripod mount. Despite missing those precious few seconds, out of about 60 shots, I got 31 where the ISS was in the frame. Of those 31 shots, 6 were reasonably sharp. The sequence below shows those six images. The change in perspective between the first and second images represents the break in shots when I hit the tripod leg. As it passes overhead, the ground-based view changes very quickly.

Click above image for larger version

I also prepared a video using the 31 images–good and bad–to show the station’s passage, especially as it receded into the southeast. I pause the video a bit where the gap in photos occurred during its overhead passage.
Quicktime ISS Video

Now that I know its possible to shoot the International Space Station with my scope and my Canon Digital Rebel, I’ll be looking for an opportunity to catch it the next time the Shuttle is docked to it. Hopefully, it will make an overhead pass in good weather during the next Shuttle mission in October.