What started as an accident in 1955 has become a Christmas tradition enjoyed by millions around the globe each year.

"Here in Colorado Springs, one of the local department stores ran an ad on a newspaper with a number to call Santa,” said Brigadier General Parker Wright, director of intelligence at NORAD. “Unfortunately, the ad misprinted the number. So, rather than calling Santa, the child called the predecessor of NORAD, Continental Air Defense."

Air Force Colonel Harry Shoup answered that first phone call, and from there, NORAD's tradition of tracking Santa was born.

"Colonel Shoup played along, knew what was going on and when he hung the phone up, he called his team together and said, 'We're probably going to get a lot of calls tonight,'" Wright said. 

For the past 66 years, NORAD has been tracking Santa on Christmas Eve using a combination of hi-tech. First, NORAD uses a ground-based radar that has 47 sites strung across Alaska and Canada.

"These ground-based radars will give us our first indication that Santa has taken off from the North Pole,” Wright said.

Once Santa hits the skies, NORAD switches over to overhead satellites. But on Christmas Eve, those satellites are used to sense the heat coming from Rudolf's nose. NORAD also tracks and protects Santa using U.S. Air Force fighter jets and Canadian Air Force CF-18's.

If you at home want to keep track of Santa, go to noradsanta.org or call 1-877-HI-NORAD.