The CubeSat sun sensor determines the spacecraft body angles with respect to the sun. The sensor is extremely small and light to minimise the demands on nano-spacecraft. The sensor achieves much higher measurement accuracy than traditional photodiode cosine sensors.

The sensor consists of a CMOS PSD detector sitting behind a small pin-hole with a field of view of +/- 57 degrees. The device produces four analogue voltages that are dependant on the incident angle of sunlight in the horizontal and vertical directions. Each sensor is supplied with a calibration algorithm that calculates the sun vector from these four voltages to an accuracy of +/-0.5 degrees.