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.

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

President Donald Trump’s executive order to create a “next-generation missile defense shield” that can “defend its citizens and critical infrastructure against—any foreign aerial attack on the Homeland” is technically and budgetarily difficult at best,