U.S. President Donald Trump has picked a design for his Golden Dome missile defense system and named a leader of the ambitious $175 billion defense program. Here are some key details about the project: HOW WILL IT WORK?

The administration’s hallmark defense project will be comprised of four layers — one space-based and responsible for sensing and tracking missile attacks, and three land-based, equipped with interceptors, radars and potentially lasers. The plans also include 11 short-range missile batteries across the continental United States, Hawaii and Alaska.