US budget watchdog estimates Golden Dome will cost $1.2 trillion, dwarfing Pentagon's $185 billion estimate

The project aims to add space-based elements to shoot down incoming threats using satellite networks and orbiting weapons

The nonpartisan Congressional Budget Office estimated on Tuesday that US President Donald Trump's Golden Dome missile defense shield could cost about $1.2 trillion to develop, deploy and operate over 20 years, a figure that dwarfs a $185 billion price tag offered by the program's Pentagon director.

Golden Dome envisions expanding ground‑based defenses such as interceptor missiles, sensors and command‑and‑control systems while adding space‑based elements meant to detect, track and potentially shoot down incoming threats from orbit. These would include advanced satellite networks and orbiting weapons.

The CBO estimated acquisition costs alone for the system would total just over $1 trillion, with the space-based interceptor layer — a constellation of 7,800 satellites — accounting for about 70 percent of acquisition costs.

The system would cover the entire United States, including Alaska and Hawaii, and would have the capacity to fully engage an attack from a regional adversary such as North Korea.

However, the CBO warned the system could be overwhelmed by a full-scale attack from Russia or China.

"The President's so-called 'Golden Dome' is nothing more than a massive giveaway to defense contractors paid for entirely by working Americans," said US Senator Jeff Merkley (D-OR), Ranking Member of the Senate Budget Committee.

The Pentagon's Golden Dome office did not respond to a request for comment.

The US Space Force has awarded contracts worth up to $3.2 billion to 12 companies to develop space-based missile defense interceptor systems. Unlike existing ground-based systems, the Space-Based Interceptor (SBI) program deploys weapons in orbit, enabling the US military to engage and destroy threats earlier in their flight path.

Ultimately companies could win lucrative SBI production contracts worth $1.8 billion to $3.4 billion annually, the Pentagon said in a presentation. But up front SBI development costs are high with industry players expected to self-fund what executives have estimated to be at least a $200 million to $2 billion effort.

Major defense contractors including Lockheed Martin, Northrop Grumman, RTX and Boeing are expected to compete for various components of Golden Dome.

An executive order to establish Golden Dome was signed on Jan 27, 2025, and set an aggressive timetable to field a comprehensive homeland missile-defense system by 2028.