ARISSat-1 and the ISS over California

September 2, 2011 | Amateur Radio, Amateur Satellite, Amateur Science | By: Mark VandeWettering

I got a tweet from twisst, the ISS pass prediction robot yesterday indicating that I’d have a good pass around 8:25PM. While I am fighting off a cold, the weather was beautiful and nice, and so I ran some path predictions to see what the path looked like, and also checked on ARISSat-1’s path to see how it was doing. I hadn’t recorded ARISSat-1 since it’s first launch weeks ago, and hoped that in spite of it’s rapidly increasing battery problems, that it would still be in sunlight, and would therefore still have a strong signal. ARRISSat-1 would lead the ISS by about 23 minutes, rising around 8:02 or so, but since I have a tall horizon to the north where it would rise, I wouldn’t expect to pick up a good signal until it cleared the hills, about 8:06 or so.

It turned out to be a really good pass: I got three different SSTV images, and some really clear audio telemetry. The first SSTV image and the last were pretty marginal, but the middle one was really clear (sad, since it was the least interesting). When I first recorded ARISSat-1 shortly after launch, I had periodic fades which I hypothesized as tumbling of the satellite: those appear to be entirely gone. I’ll have to try again to see if I can get a better and more interesting SSTV image.

After ARISSAT-1 set, I waited until 8:25 to see if the ISS would come up. I tuned into 145.825 (the ISS packet radio frequency) and waited with my iPhone camera ready. By then, it was surprisingly dark, so my camera recorded mostly just blackness, but toward the end of the clip, you can see a faint dot in the recording (and very little else). Not too exciting, but I left the audio from the radio playing in the background, so you can hear the digital packet signals being echoed through the ISS. The ISS was predicted to peak at magnitude -3.1, which made it brighter than any star in the sky, and it was very easy to see.

Here’s the resulting video. WARNING, spoiler: I forgot to edit out the “secret word” in this recording. Blame it on the cold medicine I’m on.

I’ll probably try to record another pass soon. Stay tuned.