U.S. President Trump's long-awaited "Golden Dome" missile defense system finally revealed more technical details on the 13th. According to reports, it will consist of four layers of interception systems. However, how this system transitions from presentation slides to reality remains filled with many unknowns.

According to government presentations distributed to approximately 3,000 defense contractors, the "Golden Dome" missile defense system design is far more complex than previous similar defense systems, with Trump setting a completion deadline of 2028.

The space-based component of the "Golden Dome" missile defense system consists of numerous satellites designed for early warning, tracking, and intercepting incoming missiles. The Pentagon's Space Development Agency (SDA) has previously released similar overall architecture plans, integrating existing "Defense Support Program Systems" and "Space-Based Infrared Systems" with systems under development including the "Next Generation Overhead Persistent Infrared System," "Hypersonic and Ballistic Tracking Space Sensor System," "Proliferated Warfighter Space Architecture," and "Medium Earth Orbit Missile Warning and Tracking Satellite System." These would form satellite constellations distributed from geosynchronous orbit to low Earth orbit, respectively performing ground detection, target tracking, and rapid data transmission tasks.

However, development of related space-based systems has not proceeded smoothly, and the presentation materials did not mention whether SpaceX would participate. Previous reports indicated that SpaceX had competed for the "Golden Dome" system alongside other defense contractors. The consensus is that due to Trump's very tight timeline, currently only SpaceX has the capability to conduct high-density space launches to deploy so many satellites into orbit. However, after SpaceX founder Musk parted ways with Trump, the U.S. government began intentionally reducing dependence on SpaceX, though with limited success.

The ground-based component of the "Golden Dome" missile defense system includes missile interceptors, radar arrays, and possibly laser weapons. In the upper-tier defense system, Lockheed Martin's Next Generation Interceptor (NGI) under development will work alongside the active U.S. Army THAAD anti-missile system and U.S. Navy Aegis anti-missile system for exo-atmospheric interception. The NGI will replace Ground-Based Interceptors (GBI) deployed in Alaska and California, becoming the core of the U.S. homeland ground-based midcourse interception system. According to the presentation description, beyond the current two launch sites at Fort Greely, Alaska, and Vandenberg Space Force Base, California, a third launch site will be added in the U.S. Midwest.

The "Golden Dome" system includes multiple missile defense systems from different defense contractors, and coordinating communication between these systems represents a key bottleneck. Moreover, the project's basic architecture remains uncertain, with the required numbers of launchers, interceptors, ground stations, and missile launch sites still undetermined. The Pentagon claims it is gathering information from industry, academia, national laboratories, and other government agencies to support the "Golden Dome" program, but stated that revealing more information in the project's early stages would be "unwise."

Cost is also a major concern for the "Golden Dome" system. Trump estimates the system will cost $175 billion. Congress has already allocated $25 billion for the system in the presidential tax and spending bill passed in July. Trump's fiscal year 2026 presidential budget request specifically allocated $45.3 billion for the "Golden Dome" system. Trump previously even demanded that Canada, which would "benefit from it," pay $61 billion toward the project to help cover the funding gap. However, relevant experts predict the "Golden Dome" system's actual costs will far exceed $175 billion. For example, a Congressional analysis group estimates that just the space-based portion of the system will cost over $500 billion over the next 20 years.