[amsat-bb] Request for assistance to revive AU02 and AU03 QB50 Cubesats

Joon Wayn Cheong cjwayn at unsw.edu.au
Fri Jun 2 10:45:47 UTC 2017

I'm part of the AU02 (UNSW-EC0) and AU03 (i-INSPIRE 2) Australian team of QB50 cubesats, and I'm writing here to request for assistance from the experienced and well-equipped foreign HAM amateurs experts here.

Our satellite was deployed last week and we have been unable to hear any beacons coming from it. We had several brainstorm sessions to identify possible configurations that could be changed to optimise the occurrence antenna redeployment sequence. Based on this, we devised a set of commands that reflect these changes in configurations that needs to be uplinked to the satellite. We have attempted to uplink these commands at 50W transmit power, but there's no response so far.

We strongly believe the satellite is still alive but has an undeployed antenna. As such, we require sufficient transmit gain in both transmit power and antenna gain to achieve positive uplink margin. Our problem is that we do not have the equipment to achieve the required transmit power to overcome the losses due to an unstowed configuration.

We have a recorded *.wav file that you can play through radio in FM mode to perform the uplink.

Relevant technical info:

-        The sat uses Nanocom ANT430 antenna that is still stowed. The stowed antenna is exposed on the outside of the spacecraft.

-        The sat uses Nanocom U482C transceiver.

-        The OBC might be trickling between on and off states and hence a daytime or dusk zenith pass is optimal for the uplink.

Our ground station:

-        21 el H and 21el V yagi configured in RHCP

-        Kenwood TS-2000 in FM mode with 50W transmit power.

Hope you have a good weekend, and do not hesitate to contact me at cjwayn at unsw.edu.au<mailto:cjwayn at unsw.edu.au> if you would be willing to help. Your attention has been much appreciated..

Joon Wayn

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