Y'all….Buckley AFB near Denver IAP

"Buckley is home to the only spaced-based missile warning system in the nation."

https://kdvr.com/2017/08/15/buckley-afb-at-the-forefront-of-alerting-to-missile-launches-worldwide/

https://www.youtube.com/watch?v=be6Y2i5ZdgE