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.

Trump's order establishing an Iron Dome for America includes a wider focus to defend the homeland from air and missile attacks from peer adversaries.