AO-51 magnet reversal

On Wednesday night an attempt was made to 'flip' the orientation of the Amateur Radio satellite AO-51, the first such maneuver since launch and reception reports are requested.

This operation should improve the signal in the Southern Hemisphere.

On the AMSAT Bulletin Board Drew KO4MA writes:

On the 2242UTC pass of AO-51 tonight [Wednesday, Dec 2], we will try for the first time to reverse the magnet and "flip" the orientation of the satellite. While we do this, the 435.300 transmitter will be shut off for about 10 minutes.
If the reversal is successful, we should see some changes in signal levels and patterns. This particular maneuver has not attempted since launch.

I'd appreciate any signal reports or observations from this evening and the next few days be emailed to
ao51-modes@amsat.org or ko4ma@amsat.org

In related news, as the spacecraft spin inexplicably continues to slow, we are seeing increasingly larger dips in the spacecraft voltage when the panels are poorly aligned to the sun. The immediate result of this is that we have had to decrease the power on both transmitters to prevent discharging the batteries too deeply.

We'll be working on mitigating strategies this coming month. This may include using existing software routines to automatically lower the downlink power during these dips in power production, or resolving to run one transmitter at a time instead of simultaneous digital and repeater downlinks.

73, Drew KO4MA
AMSAT-NA VP Operations

Additional note from Drew:
It will be a physical reorientation of the spacecraft. There is a large reversible bar magnet that causes the spacecraft to align it's self to the the magnetic field of the planet, and we are going to remagnetize it in the opposite sense.

Take a look at this paper, Microsat Motion, Stabilization and Telemetry, especially figure 2
http://www.coloradosatellite.com/Papers/Motion.html

AO-51 FM Repeater, V/U
Uplink: 145.920 MHz FM
Downlink: 435.300 MHz FM

AO-51 9k6 BBS, L/U
Uplink: 1268.700 MHz 9k6 FM
Downlink: 435.150 MHz 9k6 FM

The AO-51 schedule can be seen at
http://www.amsat.org/amsat-new/echo/CTNews.php

AO-51 page with real time tracking
http://www.amsat.org/amsat-new/echo/

Satellite Pass Predictions
http://www.amsat.org/amsat-new/tools/predict/

YouTube - How to work the AO-51 Amateur Radio satellite
http://www.southgatearc.org/news/october2007/
working_ao51_videos.htm