AMSAT Oscar-40 responding to commands

kb3dxs writes "Amateur satellite operators around the world got a very special Christmas/Hanukka/Solstice gift this year: AO-40 is alive and once again responding to ground control station cammands.





Mission Director Peter Guezlow DB2OS reported to the AMSAT-BB mailing list that at 21:45z on 25 December, Ian ZL1AOX sent a RESET command on L-band and an initialization block to switch on the S2 S-Band (2 GHz) transmitter



Almost immediately the S2 beacon was heard on 2401.305 MHz, at a strength comparable to levels seen during previous testing, and consistant with the direction the antennas on the satellite were pointing. Previous attempts to reestablish downlink though the V-band (2m) transmitter had been unsuccessful. Around 0500z on the 26th, stations in Europe reported receiving the S2 beacon as the satellite rose in their skies.



Around 16:05z, on 26 December, ZL1AOX is expected to again acquire AO-40 with in a favorable orbital position and will attempt to reload the satellite's control program, written in IPS. Once that is accomplished, check out and comissioning activities of the most complex amateur radio satellite to date can resume. Still to be investigated are the failure of the U-band (70cm) beacon and telemetry at launch, difficulties operating the 400 N rocket motor intended to adjust AO-40 trajectory to the desired final orbit, and subsequent loss of V-band telemetry and beacon. The satellite's current orbit is reported to be stable, so there is ample time for these operations to be conducted.

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