Deorbit Analysis

This simulation used a PID ram-pointing controller to point the +x axis (body frame) in the anti-ram direction, to perform a deorbit maneuver. The thrust was considered to be 10 mN and constant. The total simulation time was 120 seconds, during which the thruster fires for 40 seconds starting at 40 seconds. This maneuver would total 4.1 cm/s of delta-V.

The initial pointing error is near 1 degree, about 56 arcminutes, and the maximum error during the maneuver is about 0.5 degrees, or 32 arcminutes. The thruster torque that needs negating is shown on the right, the torque is 0.16 mNm about the Z-axis and 0.1 mNm in the Y-axis. For reference, the reaction wheel's maximum torque is 3.2 mNm, so there is significant margin.

The total maneuver requires an acceleration of about 2000 RPM for the primary wheel (wheel 2), and about 300 RPM for the other two wheels.