The HSNS from Solar MEMS is a Quad Thermopile Horizon Sensor that has an accuracy of less than 1 deg (EOL). It has an output data rate of 10 Hz and a field of view of ±2.5 Degrees of reach IR eye. This sensor can be used in nano and micro-satellites and is suited to LEO orbits with customization for different altitudes. This sensor has a mass of 0.12 Kg and it can measure infrared radiation from space and earth with 4 IR eyes, providing accurate and reliable detection and attitude determination. It requires a supply voltage of up to 5V and supports UART and I2C interfaces. The sensor measures 90 x 92 x 50 mm and is ideal for applications such as earth detection and nadir vector determination.