|
Part 3 of 3: (see end of article for links to the other parts)
On August 3rd the ARISSSat-1 was put into orbit by the Russian crew on the International Space Station. This Bird has six modes of Amateur Radio operation operating under the call sign RS01S and has been eagerly anticipated by the Ham Radio Satellite community.
It appears that the 21st century Ham Radio Satellite curse is still going strong! The deployment was transmitted live as the Russian crew performed several tasks during their last EVA of 2011. As the Amateur Radio world watched, the EVA crew roughly brought the new Bird outside and tethered it to the ISS, allowing it to "drift in the wind". A collective gasp was heard around the world as the camera showed us that the UHF antenna was NOT present! Immediately conjecture filled the internet as to whether the UHF whip was broken off due to the manner in which the ISS crew was handling the Bird, or if the antenna was forgotten inside, or if it was never launched with it, or ...

The 2 meter whip is on the opposite side. The mount is seen here without the short UHF whip in place.
NASA got word to the crew and delayed the deployment. There apparently was much discussion behind the scenes and eventually the decision to deploy was made by the Russian Ground Control. If the Bird was not released on this EVA, it would have had to wait until 2012, when the next EVA is scheduled.
At this time the operation of the U/V Linear Transponder is in question. There are conflicting stories as to what happened up there on August 3rd; one version has the UHF antenna "coiled" inside for transport, and others have it broken off just above the mount, or completely missing. Only time will tell if the Bird will be just another "downlink" Bird to be used for target practice, or if we will be able to make contacts with it.
The designed mode list:
Mode V Digitalker (Voices Messages and Telemetry): Operational Downlink: 145.9500 MHz FM Mode V Imaging (Robot 36 SSTV onboard cameras): Operational Downlink: 145.9500 MHz FM Mode V Telemetry (1000 baud (400 baud backup)): Operational Downlink: 145.9200 MHz BPSK Mode V TLM Beacon (CW-2, active with BPSK-1000): Operational Downlink: 145.9190 MHz CW Mode V TLM Beacon (CW-1, active with BPSK-400): Unknown Downlink: 145.9390 MHz CW Mode U/V (B) Linear Transponder (Inverting): Unknown Uplink: 435.7580 - 435.7420 MHz SSB/CW Downlink: 145.9220 - 145.9380 MHz SSB/CW
Detailed Description
ARISSat-1 is a microsat developed as a follow-on to the SuitSat-1 project. The satellite was launched to the ISS on January 28th, 2011, with deployment on EVA 29 at 1843, August 3, 2011.
The satellite will downlink live SSTV images from four onboard cameras, live telemetry and messages on the CW, FM voice, and BPSK downlinks, as well as provide a 16kHz wide transponder for two-way contacts. All the uplinks and downlinks are based on software defined radio systems.
Telemetry will include spacecraft subsystem information, as well as data from the Kursk State University experiment. This experiment will sample the change in vacuum as the satellite slowly re-enters the atmosphere. Telemetry software is now available at http://www.arissattlm.org/download/ARISSatTLM_050_Setup.exe , with a user guide at http://www.amsat.org/amsat-new/images/fck_images/ARISSatTLM-QuickStart%281%29.pdf
UPDATE!
From Bob, WB4SON, on the FunCube message forum:
"Guys I keep reading false rumors here about big-guns or high power needed to access ARISSAT. That is NOT correct. I had no issue hearing my signal on the downlink. I'm using omnidirectional low gain antennas (egg beaters) and 5 Watts produced an S8 signal that was at least 5 S units above the noise. I have NO doubt 1 watt will produce a fine downlink signal …
"What did or did not happen during the launch makes no difference now as it is working fantastically well.
"Try it. Enjoy it. No worries!!!"
Ok, I swear this will be the last Satellite article I write for a while. I’ll make my next “Bird” update when I receive a “Worked 100 stations” award. :-)
Next month … The MARC Website in detail.
Stephen, N8BP
This is part 3 of a three part series originally published in "On Your MARC" the McKinney Amateur Radio Club's Newsletter.
Each part can be found here:
Part1: Satellite Hell
Part2: Satellite Heaven
Part3: Satellite, What Satellite?
|