Slow Scan TV Transmission from the International Space Station

Saturday at 10:05 UTC we successfully received a Slow Scan Television transmission from the International Space Station. The receiver chain consisted of the USRP+TVRX, GNU Radio software for demodulating the FM signal into audio, and the freely available Digital Master 780 for decoding the SSTV data.

The transmitted picture was taken with a camera onboard the space station looking out through one of the windows. NA1SS is the amateur radio callsign used by US astronauts while they are on the space station.






Richard Garriott has been very active on amateur radio ever since he arrived at the space station. Besides the SSTV activities he has been having voice contacts with schools and radio amateurs around the world. You can listen to Richard making voice contacts with radio amateurs in Europe in this recording.

Expedition 18 lift off

Early this morning, Expedition 18 successfully lifted off from the Baikonur Cosmodrome in Kazakhstan. The Soyuz TMA-13 spacecraft, carrying U.S. astronaut E. Michael Fincke, Russian cosmonaut Yury Lonchakov and spaceflight participant Richard Garriott towards the International Space Station, is scheduled for docking to the Zarya module on 14 Oct 2008 around 9:30 UTC. NASA TV will provide live coverage of the docking event.


Image Credit: NASA/Bill Ingalls

Richard Garriott - son of former NASA astronaut Owen Garriott - has a tight schedule carrying out scientifc research and educational projects. Amongst his plans is to have live amateur radio contacts with various schools around the world using his amateur radio callsign W5KWQ. His stay on the space station also coincides with the annual Jamboree on the Air (JOTA) event giving scouts around the world an opportunity to talk with astronauts onboard the station. Something that makes Garriott's trip particularly interesting for us is his plan to turn on the on-board slow scan television equipment that will perform automatic image transmissions in Robot-36 mode.

While slow scan television is not a technically feasible option for a Lunar mission nowadays (despite the fact that it was used by many of the early Lunar missions) this event will provide an excellent opportunity to test some of our early prototypes for ground equipment using real signals from space. The International Space Station is a very fast moving object and successful reception of the images will require proper tracking with directional antennas and active compensation for the Doppler shift, caused by the high relative velocity between the space station and the receiver on Earth.

There are many external factors that might prevent this experiment from being successful. The most significant is whether the slow scan television equipment will be turned on while the space station passes over our ground station and this is, of course, out of our control. In either case, we are very excited and are looking forward to this event.