The DASH from Servo Corporation of America is an Earth/Horizon sensor with an operational field of view of +/- 5°. It has an accuracy of less than 0.2° and a mass of 0.35 g. This dual array earth sensor has a data acquisition rate of 20 Hz and requires a DC supply of +/-12 V. It has an optical pass band of 14.6-15.8 µ and an output sensitivity of ~80 mV/° linear. This earth sensor assembly is used as a part of an ACS, to sense the angle of a spacecraft relative to the infrared horizon. It has a patented Sun-Moon rejection scheme and requires no temperature control, heater, or compensation. The sensor measures relative radiant intensity in the CO2 (15u) frequency band. It produces DC voltages from redundant IR detector arrays that view the Earth, the horizon, and Space. It measures 3.75 X 2.4 X 2.4 inches and is suitable for LEO constellations with a design life of 7 years.
