Function of Component

Sun sensors detect the position of the sun and are used for attitude control. They are considered one of the “sensors & inputs” in the ADCS architecture. For more information, refer to Sun Sensors

Key Parameters

• Field of View (FOV)
  • FOV in this context refers to the extent of the observable surroundings that are seen by the sun sensor.
  • In order to achieve full coverage of the spacecraft’s surroundings, each sun sensor needs a FOV of over 45 degrees.
• Accuracy
  • Accuracy in this context refers to how correct the sun sensor’s measurement of the sun’s angle to the sensor’s normal is.
  • For the 2023 competition cycle, the primary payload required a pointing accuracy of 1-1.5 degrees while the secondary payload required a pointing accuracy of 0.1-0.2 degrees.
• Sampling Rate
  • Sampling rate in this context refers to the frequency at which the sensor makes readings.
  • For ADCS applications, the more information available, the more accurate a picture can be made regarding the satellite’s orientation. So, a higher frequency is generally more desirable.
• Size
  • Size in this context refers to the overall volume of the device as well as each individual major axis dimension.
  • Ideally, the device should be as compact as possible, on the order of 20-40 mm for its length and width and <10 mm for its height.
• Weight
  • Weight in this context refers to the overall weight of the device.
  • Since the entire spacecraft for the 2023 cycle needs to be within 4kg, the device should not take up a significant portion of that weight.
• Input Voltage
  • Input voltage in this context refers to the amount of supplied voltage that the device requires.
  • For the 2023 cycle spacecraft, the input voltage should be between 1 and 5 V, depending on its current draw.
• Input Power
  • Input power in this context refers to the amount of supplied power that the device requires.
  • For the 2023 cycle spacecraft, the input power must be less than 5W.

Selection Criteria

• Field of View (FOV)
  • Over 45 degrees
• Accuracy
  • Between 0.1 and 1.5 degrees
• Sampling Rate
  • Over 1 Hz
• Size
  • Length less than 90 mm
  • Width less than 90 mm
  • Diameter (if applicable) less than 90 mm
  • Height less than 10 mm
• Weight
  • Less than 100g
• Input Voltage
  • Between 1 and 5 V
• Input Power
  • Less than 5 W

Final Selection

The following part was selected: SS200 from AAC Clyde Space (see sources for datasheet).