From tracking Santa to Chinese spy balloons, here's what we know about NORAD

For years, North American Aerospace Command — or NORAD — had its headquarters inside Cheyenne Mountain, at the foot of the Rocky Mountains in Colorado. In this archival photo, a bus enters a tunnel for a half-mile trip to a command center inside the Cheyenne complex. The headquarters is now in nearby Colorado Springs. (Kevin Moloney/Getty Images)

It was created as a counter to a rival superpower. So in a way, it's fitting that a tiff with another superpower has once again thrust North American Aerospace Command — or NORAD — into conversations about national security and spying, as the U.S. spots suspicious balloons and objects in the sky.

For the public, the most frequent mentions of NORAD likely come in Cold War-era stories and its famed Santa Tracker, which makes the news every Christmas. But over its nearly 65-year history, NORAD has had to adjust to new threats, and its leader says it needs to modernize, citing a "domain awareness gap" and equipment that was installed in the 1970s and '80s.