Over on his YouTube channel Crazy Danish Hacker has posted a new video that shows how to pick up amateur radio voice signals from the International Space Station (ISS).
Often astronauts on the ISS will schedule times to chat with schools via amateur radio frequencies. This provides an opportunity to learn about radio whilst at the same time allowing kids to talk directly to an astronaut.
If you live in an area that can 'see' the ISS at the same time as the school then you can easily pick up the downlink (astronaut to ground) portion of the conversation while the ISS passes over. The downlink signal is fairly strong, so only a simple antenna is required. In his video Crazy Danish Hacker uses a telescopic whip attached directly to his RTL-SDR which is placed outside with a view of the sky.
International Space Station - Software Defined Radio Series #29
Earlier in the month the International Space Station (ISS) was transmitting SSTV images down to the earth for anyone to receive an decode. The ISS does this several times a year to commemorate special space related events, such as the day Yuri Gagarin (first man in space) was launched.
In the video Thomas explains why the ISS does this, how to track the ISS, and then he demonstrates actually receiving and decoding the signal. Thomas uses an Airspy HF+ to receive the signal on 145.8 MHz, however an RTL-SDR could do the same job. For decoding he uses the MMSSTV software.
For his first try he used a Baofeng (cheap Chinese handheld) and a DIY Carbon Yagi. For the second contact he used his RTL-SDR V3, an FM Trap and an LNA4ALL on a V-Dipole antenna placed on the roof of his car. With this set up he was able to receive the downlink transmissions from 1.6 degrees to 1.3 degrees elevation.
Paolo Nespoli ARISS Kontakt mit VCP-Bundeszeltplatz – 1. August 2017
Paolo Nespoli ARISS Kontakt mit FOFM / Moon Day – 5. August 2017
During July 20 – 24, 2017 the ISS (International Space Station) was transmitting SSTV (Slow Scan Television) images down to earth in celebration of the ARISS (Amateur Radio on the ISS) 20th Anniversary. The ISS transmits SSTV images on celebratory occasions several times a year. More information about upcoming ARISS events can be found on their website ariss.org.
The International Space Station periodically schedules radio events where they transmit Slow Scan Television (SSTV) images down to earth for listeners to receive and collect. This time they have scheduled SSTV images for Dec 8 1235 – 1800 UTC, and December 9 1240-1740 UTC. The ARRL announcement reads:
Slow-scan television (SSTV) transmissions from the International Space Station (ISS) are scheduled for December 8-9. The SSTV images will be transmitted from RS0ISS on 145.800 MHz FM as part of the Moscow Aviation Institute MAI-75 Experiment, using the Kenwood TM-D710 transceiver in the ISS Service Module.
MAI-75 activities have been scheduled on December 8, 1235-1800 UTC, and December 9, 1240-1740 UTC. These times correspond to passes over Moscow, Russia. ISS transmissions on 145.800 MHz FM use 5-kHz deviation, and SSTV transmissions have used the PD120 and PD180 formats.
The ISS Fan Club website can show when the space station is within range of your station. On Windows PCs the free application MMSSTV can decode the signal. On Apple iOS devices, use the SSTV app.
These SSTV broadcasts can usually be easily heard with an RTL-SDR and appropriate satellite antenna such as a QFH, Turnstile or a hand held Yagi. Many listeners have reported in the past as being able to receive them even with non-satellite antennas such as discones, ground plane, rubber duck and long wire antennas, so try your luck even if you don’t have the right antenna.
Over on YouTube user surfrockuk shows a fun and educational use of the RTL-SDR. Every now and then astronauts will arrange a ham radio session where they will communicate with a school. An RTL-SDR can be used to listen in on at least the downlink (astronaut talking) portion of these transmissions.
The following video shows astronaut Tim Peake transmitting from the international space station (ISS) on Feburary 19th 2016. He was speaking to Oasis Academy in the UK. To receive the signal surfrockuk used an RTL-SDR with a QFH antenna. Many people have reported that other simple antennas such as discones, quartwave ground planes and even long wire antennas have been good enough to receive transmissions from the ISS too.
The international space station (ISS) is currently testing transmission of a DVB-S digital video signal. At the moment only a blank test pattern is transmitted, but one day they hope to be able to transmit live video properly for the purposes of making live contact with astronauts, and possibly to stream video of scientific experiments, extravehicular activities, docking operations, or simply live views of the Earth from space.
I have been able to receive DVB-S broadcasts from the ISS (known as HamVideo or HamTV) with a high-gain 2.4 GHz WiFi antenna ($50), a custom downconverter ($65), a R820T2 dongle, and a software demodulator (Edmund Tse’s gr-dvb). I used to think this could only be done with much more expensive SDR hardware.
It is commonly known that rtl-sdr dongles do not have enough bandwidth to capture mainstream satellite TV broadcasts, but the ISS happens to transmit DVB-S at only 2Msymbols/s in QPSK with FEC=1/2, which translates to 2 MHz of RF bandwidth (2.7 MHz including roll-off).
Before anyone gets too excited I should mention that:
This was done during a favourable pass of the ISS (elevation 85°)
With a fixed antenna, only a few seconds worth of signal can be captured
Demodulation is not real-time (on my low-end PC)
Currently the ISS only transmits a blank test pattern.
I now believe the BoM will be less than $50 by the time the ISS begins broadcasting interesting stuff on that channel.
Pabr uses a 2.4 GHz parabolic WiFi antenna to receive the signal. He writes that ideally a motorized antenna tracker would be used with this antenna to track the ISS through the sky. Also since the DATV signal is transmitted at around 2.4 GHz, a downconverter is required to convert the received frequency into one that is receivable with the RTL-SDR. The DATV decoder is available on Linux and requires GNU Radio.
To commemorate the 40th Anniversary of the Apollo-Soyuz mission the International Space Station (ISS) is set to transmit 12 Slow Scan TV (SSTV) images this weekend. The images are set to transmit Saturday morning, July 18 10:30 UTC and will run through until Sunday, July 19 21:20 UTC, but they note that the dates are tentative and could be subject to change. The images will be transmitted at 145.80 MHz and will probably be sent in the PD180 SSTV mode with 3 minute breaks between each transmission.
SSTV is a type of radio protocol that is used to transmit low resolution images over radio. An RTL-SDR with appropriate antenna can be used to receive these images from the ISS. The signal is usually quite strong, so even a simple whip or long wire antenna may receive these images if placed in a good unobstructed view of the sky.
To know when the ISS is overhead you can track it online using heavens-above.com or isstracker.com. If using heavens-above to predict pass times remember to set it to show all passes, not just the visible ones. Received SSTV images can be submitted to the ARISS Gallery.
40 years ago this week, the historic joint Apollo-Soyuz mission was conducted. Apollo-Soyuz (or Soyuz-Apollo in Russia) represented the first joint USA-Soviet mission and set the stage for follow-on Russia-USA space collaboration on the Space Shuttle, Mir Space Station and the International Space Station. The Soyuz and Apollo vehicles were docked from July 17-19, 1975, during which time joint experiments and activities were accomplished with the 3 USA astronauts and 2 Soviet cosmonauts on-board. Apollo-Soyuz was the final mission of the Apollo program and the last USA human spaceflight mission until the first space shuttle mission in 1981.
To commemorate the 40th anniversary of this historic international event, the ARISS team has developed a series of 12 Slow Scan Television (SSTV) images that will be sent down for reception by schools, educational organizations and ham radio operators, worldwide.The SSTV images are planned to start sometime Saturday morning, July 18 and run through Sunday, July 19. These dates are tentative and are subject to change. The SSTV images can be received on 145.80 MHz and displayed using several different SSTV computer programs that are available on the Internet.
Also, as a special treat, on Saturday July 18 the ISS cosmonauts will take time out to conduct an ARISS contact with students attending the Moon Day/Frontiers of Flight Museum event in Dallas Texas. This Russian cosmonaut-USA student contact is planned to start around 16:55 UTC through the W6SRJ ground station located in Santa Rosa, California. ARISS will use the 145.80 MHz voice frequency downlink (same as the SSTV downlink) for the Moon Day contact. More details about these contacts are provided at Upcoming Contacts.
The ARISS international team would like to thank our ARISS-Russia colleague, Sergey Samburov, RV3DR, for his leadership on this historic commemoration.