 The NORAD command center built for the movie was the most expensive  set ever constructed up to that time, built at the cost of one  million dollars. The producers were not allowed into the actual  NORAD command center, so they had to imagine what it was like. In  the DVD commentary, director John Badham (qv) notes that the  actual NORAD command center isnt nearly as elaborate as the one in  the movie; he refers to the movie set as "NORADs wet dream of  itself."