U-2 / Terminator Line

Beale Air Force Base, located in California, is home to the U-2. This aircraft was originally designed to fly high-altitude intelligence, surveillance and reconnaissance missions during the Cold War to gather intelligence on opposition forces. Today, the U-2S flies in support of a variety of missions from ground combat to disaster relief. A “mobile” follows behind the aircraft in a chase car to assist the pilot with altitude and position calls. Mobiles are U-2 pilots who assist during taxi, takeoff and landing. While on missions, U-2 pilots often see a natural occurrence called the terminator line. According to the National Oceanic and Atmospheric Administration (NOAA), it’s a line that separates day and night. It is also referred to as the "grey line" and the "twilight zone." It is a fuzzy line due to our atmosphere bending sunlight. This "ah ha" moment is a beautiful reminder of how small we are when skimming the edge of space.