Such defense systems are extremely costly” with “their effectiveness often being questionable,” one expert said.

For more than 60 years, the military has launched reconnaissance, communications, and missile warning satellites into orbit. Trump's executive order calls for the Pentagon to come up with a design architecture, requirements, and an implementation plan for the next-generation missile defense shield within 60 days.

President Donald Trump has ordered the development of an "Iron Dome" defense system to shield the United States from an intercontinental missile attack.