AO-51 not responding to commands

AO-51 Echo LaunchNovember 29, 2011 – AO-51 not responding to commands

It is with a heavy heart I report that AO-51 has ceased transmission and is not responding to commands. The last telemetry data indicated that the third of six batteries was approaching failure to short, and observations indicate the voltage from three cells is insufficient to power the UHF transmitters. The IHU may continue to be operative. Initial tests with the S band transmitter were also not positive, although more attempts are in order. We have tried leaving the satellite in an expected state where if voltages climb high enough, the 435.150 transmitter may possibly be heard.

AO-51 AssembledThe command team will regularly attempt communications with the satellite over the coming months (and years). There is always the possibility that a cell will open and we could once again talk to our friend while illuminated. Thanks to all who helped fund, design, build, launch, command, and operate AO-51. It’s 7 year mission has been extraordinary. Please support AMSAT’s Fox-1 project, and other AMSAT projects worldwide with your time and money.

For the AO-51 Command Team,

73, Drew KO4MA
AMSAT-NA VP Operations

 

2 thoughts on “AO-51 not responding to commands

  1. Message send to amsat-bb [at] amsat.org:

    Is there an expected state when the voltage is high enough regarding AO-51.

    The reason I ask, is to listen and see if there is some life in the
    satellite when the voltage becomes high enough when there is full exposure
    after the coming eclipse periode.

    reply from KO4MA (command station member)

    It’s not so much a problem of not enough illumination, but more that we
    are running on 3 or 3.5 cells, and we need ~4 to make the transmitters
    work. There may be some points during the orbit when the V gets high
    enough for the transmitter to come on at low power, but that is
    conjecture only. We don’t know when or really even if that will happen.

    If a cell opens up in the future, the IHU will immediately crash upon
    eclipse, and the battery voltage -may- rise to whatever the panels can
    provide. If this happens we may be able to restart the IHU and get a
    transmitter running, but it will only last until the next eclipse.

    73, Drew KO4MA

  2. Special ANS bulletin

    AMSAT-NA VP Operations, Drew Glasbrenner, KO4MA reported today,
    “It is with a heavy heart I report that AO-51 has ceased trans-
    mission and is not responding to commands.”

    Drew wrote, “The last telemetry data indicated that the third of
    six batteries was approaching failure to short, and observations
    indicate the voltage from three cells is insufficient to power the
    UHF transmitters. The IHU may continue to be operative. Initial
    tests with the S-band transmitter were also not positive, although
    more attempts are in order. We have tried leaving the satellite in
    an expected state where if voltages climb high enough, the 435.150
    transmitter may possibly be heard.”

    The command team will regularly attempt communications with the
    satellite over the coming months (and years). There is always the
    possibility that a cell will open and we could once again talk to
    our friend while illuminated. Thanks to all who helped fund, des-
    ign, build, launch, command, and operate AO-51. It’s 7 year mission
    has been extraordinary.

    Please support AMSAT’s Fox-1 project, and other AMSAT projects world-
    wide with your time and money.