[amsat-bb] Being prepared for satellite SSTV is better than not.
ka1rrw at yahoo.com
Mon Sep 8 11:25:40 PDT 2008
It’s better to be prepared (SSTV on ISS)
It is better to be prepared for the arrival of new projects on ISS, rather than being caught off guard for a project. In July 2006 the ARISS team was caught off guard by Commander Pavel Vinogradov on board ISS when he called Russian Mission control and informed them he was going to test Slow Scan TV from ISS, via a borrowed laptop computer. Pavel wanted to use SSTV to communicate with families and friends around the world during his ISS mission during the summer of 2006
At ARISS we were not expecting SSTV for another year at least since we still did not have an allocated laptop for Amateur Radio operations. We were also missing one chapter in the SSTV manual, and that was the chapter explaining which buttons to push on the D700 to take it out of cross-radio packet mode and put it on a pair of channels for SSTV. After a few tries, Commander Pavel Vinogradov was able to get the D700 into Simplex mode and we began to see a hand full of SSTV images coming down from ISS for the first time.
Since Pavel had set the radio to the wrong frequency we did not push this information out to the Amateur Radio public for political reasons. The down link frequency was perfectly legal under ITU Laws, however it was not one of the gentlemen’s agreement frequencies (ITU Laws, Satellite band 2-meters uplink and downlink, 144.000 – 146.000 MHz).
As a result of being unprepared, we missed a great opportunity to show the world what we can do with Amateur Radio SSTV in space. To date we are only aware of 8 unique images sent to Earth from ISS via Marex SpaceCam.
Two years later, we are still not prepared.
Astronaut tourist Richard Garriott’s is interested in using SSTV as part of his mission. Assuming the big huge stack of papers is signed by a bazillion people we may see some SSTV.
We still do not have a dedicated laptop.
We still do not have chapters for setting up the D700 (see side notes #1 on the D700).
So while ARISS and the space agencies are busy shuffling papers, we should not sit idly by and wait. We should be ready for the possibility of SSTV from ISS during short Garriott’s mission in October 12-20th, 2008.
After all, for a 30 million US dollar space ride ticket, you do have some say in what project you want to run while on board ISS.
So, Dust off your 2-meter station.
Download your favorite SSTV application.
Plug your computer into your 2-meter station and start experimenting terrestrially with other friends on 2-meter FM SSTV.
As for Future Amateur Radio projects on ISS, you need to Tell ARISS/NASA what types of projects you think would be beneficial to the Amateur Radio space program.
Do you still want Packet?
Do you want a cross band repeater?
Do you want Streaming SSTV?
Do you want Streaming Web quality video?
Note: Fast scan TV will not fit in the satellite ITU band segments.
Data speeds over 1 megabit are not practical because of Doppler issues and the cost of your radio station will be out of the reach of most of us.
ISS Available Resources:
We currently have 7 coax cables on ISS that are connected to real antennas on the outside hull of ISS, which can be used for Amateur Radio projects.
Only one of these cables is currently connected to an amateur radio project (Kenwood TM-D700) the rest of the cables are not currently being used and are available for Amateur radio projects.
Cables 1-3 Multi-band antennas, 2-meters, 70cm and a patch 1.2-2.4 GHz (high coax loss above 1.2 GHz)
Cable #4 10 meters receive only antenna (will need a spacewalk to attached ground radial if you need to transmit on 10 meters)
Cable #5 2-meter antenna in FGB module (co-phased antennas tuned for 147 MHz)
Cables #6 1.2 GHz patch Columbus module (Note #2)
Cables #7 2.4 GHz patch Columbus module
D700 Sidebar #1:
The D700 on ISS is programmed with a unique and very complex configuration that uses both receivers and transmitters in a cross radio configuration (not cross band, cross radio). Both voice and packet modes are running for most modes at the same time. The cross radio setup made it very difficult for the crew to change channels manually, because you had to set transmit and receive channels on each radio separately. This is way Commander Pavel had such difficulty in finding a channel that would work with SSTV.
The cross-radio setup caused numerous problems and ARISS finally agreed to develop a simpler software setup. The new settings have been tested on earth and a subset of the changes was manually installed on the ISS D700. Once we turned off cross-radio operations we noticed a significant improvement in ISS packet performance.
As of this writing the full new software load for the ISS D700 has not been scheduled.
Side Bar #2 Columbus module:
At the present time the two antennas on the Columbus module are earmarked for Amateur Radio digital TV. Just need working hardware.
Miles Mann WF1F, former ARISS technical consultant.
Mir SSTV images
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