Would you like to receive pictures directly from the International Space Station (ISS) and become a radio communication pro? Then watch this instructional video, prepared for you by the ESA Education team with several of its ESERO Offices and other international partners, such as ARISS and the Goonhilly Earth Station.
You’ll find out how to use a software-defined radio receiver accessible from a web browser to collect the ISS pictures. A range of step-by-step tutorials will show you how to set up the required software, test it and then obtain the pictures the ISS is sending on your computer or smartphone. There are seven tutorials in total covering Windows 7, Windows 10, Mac OS, Raspberry Pi, Ubuntu, iOS/iPhone and Android.
Please note that we are expecting the ISS to transmit pictures in the next weeks for the 45th anniversary of the Apollo-Soyuz test project*. A perfect opportunity to try this activity for real yourself!
*Correction: We posted about the Apollo Soyuz commemoration event in error, this was due to a misunderstanding on our part. However on August 4 and 5 the ISS did transmit SSTV for several hours on both days (details here). Please see below for the results.
Note for the teachers
This activity is focused on strengthening the learning of curricular topics, such as the electromagnetic spectrum and radio waves behaviour and propagation, through amateur radio communication techniques.
The practical activity presented here will be in future complemented by additional classroom resources that include simple additional experiments.
Watch here the tutorial for your chosen OS.
Results: SSTV transmission from ISS on 4/5 August 2020
The ISS transmitted Slow Scan Television pictures on 4 and 5 August. This was a Russian-led activity from the Moscow Aviation Institute and so the transmission times were set to coincide with orbits that overflew Moscow. This meant the transmissions started before the ISS passed over Europe, therefore Europeans had good opportunities to receive the pictures.
Typically, a picture is transmitted for 2 minutes, followed by 2 minutes of off-time to allow the radio transmitter on the ISS to cool down. On 4 August the off-time between pictures was around 5 minutes, possibly due to an accidental setup error. However on 5 August it was back down to the normal 2 minutes, allowing more pictures to be received per ISS pass.
The 12 different images were transmitted in a linear sequence with no randomisation. As a result, the same 4 or 5 images kept coming up on the Goonhilly Web SDR. The collage shows the pictures received by the ESA Education team.
Unluckily, image 5 and 6 were never received at Goonhilly. Due to the way the Earth’s horizon blocks the signal from the ISS, and to the fact that the 2 min on / 2 min off transmission does not respect the horizon of any radio receiver on ground – it is possible for the ISS to be in the middle of sending a picture when it rises over the horizon (see pictures 7 and 9) or in the middle of sending a picture when it sets below the horizon (see picture 4).