What is Musk-led SpaceX's plan for US 'Golden Dome' missile shield?

Elon Musk's SpaceX, with startups Anduril and Palantir, are frontrunners to build a 'Golden Dome' missile shield for the US. The companies would launch 400 to more than 1,000 satellites circling the globe to sense missiles and track their movement, Reuters reported. A separate fleet of 200 attack satellites armed with missiles or lasers would bring enemy missiles down.