Contact from the International Space Station!

To celebrate Cosmonautics Day on April 12th, the International Space Station began transmitting slow scan tv images related to the Interkosmos project from April 11th-14th, using a Kenwood TM-D710 transceiver located in the Russian ISS Service module which broadcasted on the frequency 145.800 MHz. I found out about this event from an amateur satellite radio organization called amsat; and with my new interest in radio image reception, I planned to attempt to make contact with the ISS and decode some of these images.

I purchased a Baofeng UV-5R handheld radio capable of receiving radio transmissions on the specified frequency (which my SDR / antenna combo from part 1 of “Selfies from Space” could also receive, but was more unwieldy to use), and used a Sony voice recorder to record the transmissions. I could then  play back and decode the transmissions with a program on my PC called mmstv, or an app on my phone called Robot36. While it is possible to decode the recorded transmissions in realtime, I preferred to record the transmission and then try different programs/settings to decode the recording. I also used a website called satview to look up times when the International Space Station would be overhead, as these intervals would be short in duration (around 6-8 minutes) and the transmission equipment on the ISS required a minute or two of rest time between sending images. This meant that I might have only captured part of one image and then the whole of another image, or the whole of one image then part of another one, depending on timing. Finally, I also struggled with radio interference, which resulted in some of the images I captured being fuzzy.

Below are some examples of images I decoded from the ISS during this radio event:

Finally, here is a video demonstrating decoding of one of these image transmissions using the App Robot36 on my phone (Note: you may want to turn your sound down if you are sensitive to certain noises).

I look forward to future events like this, and – if I set up a radio transmitter – maybe even getting the chance to talk to an astronaut!


Picture credits:

All photos provided and owned by Gary Dewey.