Messages from Space 2021

Every year between Christmas and New Years Day, the International Space Station reconfigures their amateur repeater to continuously send slow scan television images to Earth. Slow scan television is something like a facsimile image. The color and brightness of each horizontal line of the image is represented by audio tones transmitted over the radio. To receive these images you need a VHF FM radio receiver and software to record and decode the images. You also need software loaded with what are called the "Keplerian elements" -  numbers that predict the orbit of satellites such as the ISS. This enables you to tell when to tune in and where to point the radio antenna. Typically a satellite will be in range for ten or so minutes when it passes overhead. 

Last year I posted a slow scan television image that I received on from the International Space Station over the winter break. For that I used my FT-2980 transceiver wired to my PC and a ground plane antenna. The images I received were pretty clean.  This year I was visiting relatives and had only a laptop and an FT-60 handheld with a "rubber duck" antenna. With the assistance of my niece, we tuned in and held the radio up to the laptop and were able to capture some images. 

Quality wasn't perfect because the microphone in the laptop picked up sounds around us - such as this:

The software we used to decode the images was called QSSTV. This app not only converts the tones into an image, it provides some visualization of the incoming signal. If you are wondering what a rooster crow looks like in a waterfall plot, here it is:

A waterfall plot breaks up tones and displays the lower tones on the left and higher tones on the right. As new tones are captured and analyzed, they are added to the top, and the image scrolls down. Most of the fuzzy lines across the images, however, occurred when the signal from space randomly faded out. It wasn't because of the chickens!

The theme this year was lunar exploration, and there were twelve different images sent commemorating various moon missions. All amateur radio stations must identify themselves, so in the images you can see the U.S. callsign NA1SS and the Russian callsign RSOISS. The onboard station is operated by astronauts from both nations.

ARISS (Amateur Radio on the International Space Station) was offering a certificate for anyone sending a copy of their captured image along with information about how and when the image was received. We filled out the form, sent it in, and the next day received this certificate: