26 September 2009
24 September 2009
After correcting the TLE information, our communication with the satellite is more consistent and reliable.
We intend to affect the improvements that we made to our ground station equipment, to the SAC ground station in the coming week.
22 September 2009
The two autonomous Attitude Determination and Control System (ADCS) controllers (Bdot and Y-Thompson; Bdot-Sun) running on a small micro processor on the magnetic subsystem (no floating point processing) are perfectly pitching the satellite at 2°/sec with the main body-mount solar panel facing the sun. The power system is therefore running optimally. We are satisfied with the thermal state of the satellite in the current basic attitude control mode.
As expected, the 500km orbit of the satellite causes incidences of short contact opportunities with the satellite due to the fact that our ground station is located at the Engineering Faculty (in Stellenbosch) where it is surrounded by various high mountains. We have identified certain aspects in our communication setup on the ground which can be improved to make the communications with the satellite more robust and reliable.
In addition, we are re-evaluating the possibility to extend the contact time with the satellite by also employing the Sumbandilasat TT&C ground station at SAC (Hartebeeshoek), by remotely controlling passes from Stellenbosch.
At the moment we are focusing on the commissioning of the main On-Board Computer that will allow us to collect whole-orbit telemetry data, calibrate the magnetometer and proceed to the more advanced ADCS control modes on the main Attitude Computer.
We are extremely pleased with our baby in space!! Our first pass last night at 20:48 local time was a very low elevation Eastern pass with some mountains obscuring the “view” as well, but the satellite responded beautifully almost immediately after sending the first command from the Stellenbosch ground station!
We received real-time telemetry which suggested that the satellite was already executing an autonomous attitude stabilization maneuver. This was confirmed during the second pass where we also had good communications. This morning the satellite was stable in a sun-Thompson mode.