3.2 Attitude and orbit control
We then focussed on the control system for keeping the satellite in a particular orientation (attitude).

19 October  2011
First we talked about assignment #2. Then we talked about the sources of rotational torque. We leaned about earth, sun and star sensors and how an eroneous attitude is corrected. We then focused on the three-axis stabilization.
We looked at the engineering model of the RadioAstron spacecraft. We also saw the focus cabin, the flywheels,
the gas tanks and the gas jets.

21 October  2011
We discussed homework assignment #2. We then  covered issues related to the orbit control and compared
the fuel allocations for various maneuvers.

3.3 Telemetry, tracking and command (TT&C)
We talked about the measurement of the orientation,  the environment  and the health of a satellite
and how these measurements are transmitted.  Then we covered issues related to the tracking
of a satellite. We talked about how commands are executed.

24 October  2011
We talked about assignment #2.

3.4 Transponder
We learned about uplink and downlink and talked about
radio bands and the corresponding frequencies.


26 October  2011
We talked about assignment #3. We interpreted the block diagram of a transponder.

28 October  2011
We had our midterm exam.

31 October  2011
We discussed the TWTA . Then we learned about solid state amplifiers and about amplification in the
non-linear regime and intermodulation noise. Click here for a different perspective.

2 November  2011
We learned about wire, horn and reflector antennas, the radiation pattern, the 3dB-beamwidth, and the gain
of an antenna. We talked about the degradation of the gain as a function of the roughness of the antenna surface. Then we turned to Chapter 4.