ARISS SSTV - Expedition 72 - Humans in Space

Receiving SSTV images from the International Space Station is fairly easy and the reward is somewhat significant (in my opinion). The tools you need to receive and decode the images are probably already in your possession if you're a licensed ham. Of course, you can always improve and "complicate" things, but both the minimum equipment and effort requirements are cheap.

The quick and hassle-free way is to use a smartphone app like Robot36 together with a handheld radio to decode the images in real time. No need to record anything, you get the results right away.

The slow and dirty way - record the audio and later decode it using a variety of programs on the computer.

My setup

Receiver: Yaesu FT-65 handheld radio with stock antenna (any receiver capable of getting 145.800 FM should work).
Audio recorder: Smartphone (any audio recorder should work).

That is all you need to acquire and record the signal. Once you have the audio recorded, you can always decode it later on the computer.

The software I use

All the listed programs are freeware.

• Skipping Silence Recorder for Android - used on the phone to record audio. Alternatively you can install Robot36 and directly decode the image, without recording the audio.
• Audacity for Windows - used to playback the recorded track.
• VB Cable for Windows - a virtual audio device working as a virtual audio cable which allows you to playback and input the recording into the SSTV image decoding program.
• RX-SSTV for Windows - a SSTV decoder that will allow you to convert the ISS recorded audio to images.
• Gpredict for Windows - a satellite tracking and orbit prediction app that will help you plan your receptions (will basically tell you when the ISS passes over your location so you can record it). I also used Orbitron for sat tracking. Make sure your telemetry data is up to date (otherwise the ISS visualizations and predictions will be incorrect and your efforts useless).
  

The process

Once I know there's gonna be an ISS SSTV transmission, I use Gpredict or Orbitron to get the ISS pass predictions - a schedule with the times, elevation and direction of the ISS in respect to my location.
Then I prepare my handheld radio and make sure my radio/phone battery and phone memory are all up to the task. The equipment is portable so I can carry it around in my pocket or backpack.
So when the time comes I move into position, trying to find a spot where the horizon line toward the ISS is the most open. Even when inside the city, between buildings, you can still get some results (my first two images were recorded in such conditions).
I open the radio, check that I'm on the right frequency (145.800 FM) and remove the squelch so I can hear everything. I also press record on my phone. I have no cable to connect the radio to the phone, so the recording will pick up any external noise as well, but the whole SSTV business is far less susceptible to external noise than I imagined.
After I record the track, I go to my computer and I play it back through the Virtual Cable to the RX-SSTV app, which converts the audio to an image (if the settings are right and the audio quality is decent).

Results

I've heard about this scheduled SSTV transmission thanks to YO8AZQ and other ham ops in the area. From the official ARISS announcement:
"Expedition 72 - ARISS Series 26 Humans in Space" mission
April 11-16, 2025 – Humans in Space
April 12 is the International Day of Human Spaceflight so, what better theme for the April 11-16 Slow Scan TV transmissions.
Start: Friday, April 11 1700 GMT
End: Wed, April 16 1430 GMT
Frequency: 145.800 MHz FM (+/-3.5 kHz Doppler Shift)
The callsign is RSØISS, frequency is 145.800 MHz, and the mode is PD120. (Transmission cycle 2 minutes on, 2 minutes off)."

I've uploaded the received images to the https://ariss-usa.org/ARISS_SSTV/ gallery and applied for a certificate of participation which came via email in a couple of days.

Here's an audio file sample recorded on 16 Apr 2025, if you're curious:

2025_04_16__11_58_26.wav
File Size:	5428 kb
File Type:	wav

Download File

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Notes

Image quality, in general, depends on your equipment (quality of antenna, receiver), on your position (buildings, wires and urban/industrial noise could affect the reception), on the elevation of ISS over your location (how good the pass is) and on the attitude of ISS (how the Intl Space Station and its antenna is turned in respect to your location). In addition to this, the ISS transmission has 2 minute pauses between each emission, so even if you get a good ISS pass, the 2 minute pause might fall at the worst time possible. Still, there should be plenty of chances to get decent reception during a 5 day SSTV transmission such as this one that just ended yesterday.

- Alex, YO8SBR