Wide Angle Earth Sensor

Servo, under contract to NASA, Goddard Space Flight Center has developed a 120 x 5 degree instantaneous field-of-view (FOV) Wide Angle Earth Sensor (WAES) for use on missions that require a "safe hold" with some level of pointing accuracy to protect payloads from viewing the Earth. Developed especially for NASA’s WIRE (Wide-Field Infrared Explorer) mission, the WAES consists of two Sensor Heads and an Electronics Control Unit. On the WIRE mission the sensor heads are arranged back to back 180 degrees apart such that they can monitor one axis of rotation, while a sun sensor is used for the other axis. The predicted accuracy is 1.5 degrees exclusive of radiance errors and 3.5 degrees inclusive of radiance errors.