News from Vietnam

Inspired by our Open Source Communication Lab, our friends from Vietnam have started to play with software radios using the USRP and GNU Radio. After a few weeks of study they are now able to receive Automatic Picture Transmissions from the NOAA weather satellites as well as signals from current amateur radio satellites in low Earth orbit.

Inevitably, they have now formed a group of young engineers who are interested in ham radio, electronics, robots, astronomy and space exploration. At the moment, they work in the newly established FSpace lab of FPT Corp. where Thu (who is active on our forum) used to be a software engineer. He has now quit that job to pursuit his dream of space exploration.

Their current project is to design and manufacture a nanosatellite which will measure about 10x10x30cm and weight about 3kg. They expect to have it ready in 18 months (starting from 1/1/2009) and launch it to LEO (600-800km, sun-sync orbit) by the end of 2010. This is the first time they've ever worked in a real space mission. While they understand that there are many things to learn and many difficulties ahead, they are confident that they can do it if they try hard. Currently, they have 4 full-time people (Thu and the other 3 in the photo) and about 10 supporters/collaborators of the project.

From Communication Equipment

PS: Thu has recently passed his amateur radio exam and has now the callsign XV9AA.

Scheduled Radio Contact with the ISS

If you happen to live in Europe, you'll have the chance to listen to the astronauts from the International Space Station as they talk to students from Städtisches Gymnasium Herzogenrath in Germany. The event is scheduled for Saturday Feb 7 and it will begin at approximately 10:36 UTC.

You will need a radio receiver capable of receiving 145.800 MHz narrow FM. The signals from the ISS are usually rather strong and a handheld scanner should be able to receive audible signals.

I don't exactly know which astronaut will be speaking but they will use the ham radio call sign OR4ISS.






The students will ask as many of the following questions as time permits:
1. To what extent do we on earth profit from your experiments on the ISS?
2. What are the aims of your present mission?
3. How much energy do you need daily and what kind of energy is it?
4. What about radiation on the ISS? Does it harm your health?
5. Have you had any problems with oncoming meteorites or space debris?
6. Which qualifications do you need to be on such a mission?
7. What were your feelings and emotions during lift off?
8. Do you lose your sense of time on the ISS?
9. How do you spend your free time on the ISS?
10. Have you got any room for your personal belongings?
11. What happens if you are ill?
12. What happens to the human body if you stay in space too long?
13. How often do you see the sunrise on the ISS per day?
14. What happens in case of an emergency, for example if the ISS is on fire?
15. Can you sleep well in a state of zero gravity?
16. How do you wash your hair?
17. How many experiments do you do a day?
18. Have you and your colleagues become friends?
19. What would you say is your most important experience on the ISS?
20. When do you think will mankind be able to leave our solar system?

ARISS is an international educational outreach program partnering the participating space agencies, NASA, Russian Space Agency, ESA, CNES, JAXA, and CSA, with the AMSAT and IARU organizations from participating countries.

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.

VHF/UHF Receiver

The picture below show a VHF/UHF receiver assembly based on the Universal Software Radio Peripheral and a standard TV-tuner. The board on the left is the S-band transceiver module described earlier.



The TV-tuner based VHF/UHF receiver can receive a 6MHz wide RF spectrum anywhere in the range 50-800MHz. It has a noise figure around 8dB, which is not good enough for Lunar comms; however, it is a good cheap starting point for breadboarding and experimentation. Using a modest yagi antenna and a low noise preamplifier, we have been able to receive signals from low Earth orbiting satellites.

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.

Transceiver modules for the L and S bands

The RFX1200 and RFX2400 daughterboards provide complete radio frequency transceiver interfaces for the Universal Software Radio Peripheral in the L and S bands. The receivers have an AGC range of 70dB. The transmitter output is around 200mW for the RFX1200 and 50mW for the RFX2400. The transmitter and receiver frequencies can be controlled separately (split mode) and the boards are also capable of full duplex operation.