[amsat-bb] ARISSat-1 startup sequence

Gould Smith gouldsmi at bellsouth.net
Sun Apr 10 10:37:10 PDT 2011


The task for the cosmonauts to turn on ARISSat-1 is scheduled to begin at 1430 UTC on April 11. That means that they will begin the procedure of getting the satellite, moving the antenna coax, adjusting the antenna switches in the ISS, then flipping the three switches on the satellite control panel to ON. These switches and the circuitry are designed to keep the satellite from transmitting for 15 minutes after all three switches are in the On position. This was done so as not to pose any hazard to the cosmonauts during the EVA to deploy the satellite.

Given all these activities I suspect that there will be no transmissions until around 1500 UTC. According to my tracking software this puts the first coverage area in the southeastern Pacific. Other than ships, southern South America should be the first area to hear the 
ARISSat-1/RadioSkaf-V signals.

The satellite will be in Low Power mode, 40-60 seconds ON and 2 minutes OFF. An average 8 minute pass will only have about three transmission periods and two minutes can seem very long when waiting for a signal to appear. Be patient
The varying ON times occur because when the On timer expires the current FM transmission item (ID, telemetry, greeting, SSTV) will finish before the transmitter shuts off.

Enjoy the event in celebration of the 50th Anniversary of man's first trip into space. Yuri Gagarin make the historic trip on 12 April 1961.

Gould, WA4SXM

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