The Vigilant Eagle Airport Protection System is a proposed directed-energy weapon under development by the U.S. military under a Defense Department contract with Raytheon. It would create an invisible microwave dome around an airport that could block missiles heading toward incoming and outgoing aircraft. A successful attack of this kind would cause more than loss of life. The estimated cost of a four-hour operational shut down of an airport is $40 million. This would have an estimated $10 billion impact on the U.S. economy and an estimated $300 billion impact globally.