Trump estimated the Golden Dome project to cost $175 billion, with a $25 billion down payment. A recent Congressional Budget Office estimate put the total cost of deploying and operating a constellation of space-based interceptors for 20 years at anywhere from $161 billion to $831 billion.

Donald Trump unveiled concepts for his £400 billion Golden Dome missile defence program at the White House, which he hopes will be "fully operational" before the end of his term in 2029