Attitude Determination & Control System

Group 930 & 931

Requirements

• Inertial pointing satellite.

• Pointing Accuracy (10 deg off axis).

• Slew (25 deg off axis).

• Minimize power consumption

Control Modes

• Detumbling.

• Fail Safe.

• Power Save.

• Camera Control.

• (Communication Control).

Sensors

• Magnetometer.• Horizon Sensor.• Rate Gyros.• Sun Sensors.

Sensor combinations

1. Magnetometer & Sun Sensors.2. Magnetometer, Sun Sensors & Rate Gyros.3. Horizon Sensor, Sun Sensors & Rate Gyros.4. Horizon Sensor, Magnetometer & Rate Gyros.5. Horizon Sensor, Sun Sensors, Magnetometer & Rate Gyros.

Actuators

1. 3 x Magentorquers.

2. 3 x Magnetorquers + 3 x Momentum Wheels.

3. 2 x Magnetorquers + 1 x Momentum Wheel.

4. 3 x Magnetorquers + 1 x Momentum Wheel.

Control structureControl structure

Interface to CDHS

1. Receive NORAD lines

2. Receive Time synchronization

3. Receive Control mode

4. Receive Solar panel info

5. Send Housekeeping

6. Send Alarms

Interface to CDHS

Mass budget

Magnetorquer(x3) 20g

mounting 5g

Momentum wheel 20g

mounting 5g

PCB+components 50g

Total……………………100g

Mass budget

Power budget

nominel peak

Magnetourqer 150 mW 150 mW

Momentum wheel 50 mW 200 mW

Actuator 20 mW 20 mW

Sensor interfaces 20 mW 20 mW

Total…………………… 240 mW 390 mW

Power budget