Horizon Sensor, Earth/Lunar

This is an unflown specimen of a sensor that located the horizon of the Earth or Moon by sensing the change in infrared radiation as the device scanned the horizon. After locating the horizon, it was able to determine the local vertical at that point. The sensor was probabaly used during the Gemini program, during missions where a Gemini spacecraft rendezvoused and docked with an Agena target vehicle.

NASA transferred it to the Museum in 1973.