The Pentagon’s “Golden Dome”: What We Know about America’s Proposed Missile Shield

Even before his first week in the Oval Office was finished, the newly elected U.S. President, Donald Trump, had announced the need to create a new continental missile defense system for the United States, modeled after Israel’s Iron Dome. The President signed an executive order on January 27, 2025. However, Israel’s territory is 445 times smaller than that of the U.S., which suggests that the new missile defense system will encounter significant technological challenges for the country’s industrial sector and economy.  

While newly appointed Secretary of Defense Pete Hegseth is still working out the details of this ambitious megaproject (the reference architecture for the new missile defense system must be presented within 60 days of the order’s signing), we decided to analyze what the American version of the Iron Dome—the so-called “Golden Dome,” as the project has already been dubbed—might look like.

SDI: early missile defense concepts during the Cold War 

The Strategic Defense Initiative (SDI) was a program introduced during President Ronald Reagan’s administration in 1983. Its ultimate goal was to establish a comprehensive missile defense system, including space-based interception systems. This missile defense shield was intended to cover the entire territory of the United States. Initially, the program was managed by the Ballistic Missile Defense Organization (BMDO).

Research efforts began immediately after the SDI budget was approved in 1983. Space-based missile defense systems were not limited to the deployment of interceptor satellites in orbit. Instead, the program explored multiple alternative methods for countering ballistic missiles during flight.

At the inception of SDI, the U.S. considered deploying a constellation of interceptor satellites in Earth’s orbit, armed with conventional anti-aircraft missiles. This concept was a continuation of the BAMBI (Ballistic Missile Boost Intercept) system, proposed in the U.S. in the 1960s. The project envisioned the deployment of space-based interceptors (SBI)—essentially missile-equipped satellites designed to destroy ballistic missiles in space. However, BAMBI was never implemented due to the signing of several international treaties in the 1960s that restricted the deployment of weapons in space. Despite this, the concept was revisited at the start of SDI development.

However, early feasibility studies revealed several weaknesses that led to the abandonment of the new space-based interceptor program, which was known as “Brilliant Pebbles.” First, the satellites were technologically complex, making their development and deployment prohibitively expensive. Second, missile-equipped satellites directly contradicted key provisions of the 1967 Outer Space Treaty (OST), which the U.S. had played a major role in establishing. These factors prompted BMDO to focus on developing other space-based missile defense systems.

Among the primary alternatives considered were laser, electromagnetic, ultra-high-frequency, and kinetic countermeasures. Missile interceptors were also regarded as a reliable and relatively cost-effective technology. However, in the later stages of the initiative, they were proposed for deployment not in space but as new types of ground-to-space and air-to-space anti-missile systems launched from fighter jets. This meant that, in the later phases of SDI, missile interceptors were seen as the last line of defense, while earlier stages focused primarily on laser satellites and similar technologies.

For SDI satellites, several types of lasers were proposed at different stages of the program’s development:  

• X-ray laser: This concept involved triggering a nuclear explosion to generate a large amount of ionized plasma within special nuclear rods inside a launch vehicle. The resulting high-intensity X-ray radiation in the first seconds after detonation would create a directed laser beam aimed at disabling ballistic missiles. These nuclear-laser missiles were called “Excalibur.” To circumvent OST provisions prohibiting nuclear weapons in orbit, these missiles were to be launched from submarines in the first seconds of detecting Soviet ballistic missile launches. However, the extreme technical complexity of the system and the need for a nuclear detonation in space led to the cancellation of the directed X-ray laser concept.
• MIRACL (Mid-Infrared Advanced Chemical Laser): This chemical laser was intended to be deployed in orbit on specially equipped satellites (or, according to some proposals, orbital stations) codenamed “Battlestar.” The laser pulse was generated through a chemical reaction and was aimed at the thin metal walls of an ascending missile’s fuselage. Ground tests showed that a 2.2 MW laser could destroy a missile mockup at a distance of one kilometer. However, this range was insufficient for space-based applications, leading to continued upgrades to increase MIRACL’s power until SDI was canceled in 1993. 
• Orbital mirrors: Another laser-based SDI concept involved a system of orbital mirrors that would reflect laser beams directed at them from ground-based stations. This was the easiest and most economically viable orbital laser setup. However, it faced significant technical challenges: due to vast distances and the high absorption rate of Earth’s atmosphere, the ground-based laser stations would have needed to generate an initial beam of at least 1,000 GW. This required constructing dedicated power plants (including nuclear) to sustain the laser during a missile attack; otherwise, there was a risk of overloading the entire U.S. power grid.

Other non-laser SDI concepts developed over its 10-year existence included:  

• Neutral particle beam weapons, which could generate a directed stream of subatomic particles accelerated to near-light speed to bombard the guidance electronics of ballistic missiles. 
• Railguns, which would generate directed electromagnetic radiation. 
• Tungsten buckshot, released by detonating a nuclear warhead near an incoming missile.

A separate concept was that of kinetic energy weapons, represented by the Homing Overlay Experiment (HOE), developed by Lockheed in the 1970s. This project proposed a kinetic interception system that could disable nuclear warheads by colliding with them at speeds of 12–15 km/s. The kinetic projectile of HOE featured an umbrella-like mechanical extension with a 4-meter diameter, which deployed upon entering space. However, its major drawback was an extremely small kill zone, limited to the diameter of the umbrella itself. This required HOE to have an exceptionally advanced target-tracking system, which was difficult to achieve at the time.  

Four HOE tests were conducted. The first three failed, but during the fourth, the system reportedly intercepted a Minuteman ICBM at an altitude of 160 km. However, the success of this fourth test in 1993 was later questioned in a New York Times article, which alleged that test results were falsified to secure additional funding and extend the program. This led to a government investigation in which Pentagon officials admitted to Congress that they had indeed altered some test data. However, they claimed these alterations did not critically affect the overall success of the system.

The data falsification during the fourth HOE test serves as a fitting illustration of the entire 10-year journey of the SDI. Today, some researchers believe that the primary goal of the program was not the actual deployment of space-based missile defense systems but rather to provoke the USSR, America’s main strategic rival, into an economically draining technological competition. Whether this was indeed the strategic objective of SDI remains uncertain, but one fact is clear: during its development, the Soviet Union collapsed and ceased to exist. Two years later, in 1993, the program was shut down as unnecessary, since the U.S. no longer faced the threat that had prompted its creation.  

Estimates suggest that the U.S. spent between $100 billion and $200 billion on the initiative over its 10-year lifespan. While some SDI projects undeniably consumed vast amounts of funding without yielding results, others contributed to the development of space-based missile defense technologies that, in an evolved form, are still in use by the U.S. today. Several principles outlined in the SDI during the 1980s were revived in 2019 as part of the newly established Space Development Agency (SDA).

Missile Defense in Small Territories: The Case of Guam

The peculiarity of the Iron Dome missile defense system, which protects Israel, is that it covers a relatively small area. A single Iron Dome battery covers 388.5 km² (or 150 square miles). In the case of Israel, with a total area of just over 22,000 km², the strategic placement of a limited number of such missile defense batteries can fully shield the country from missile attacks.

The mainland territory of the United States simply cannot utilize systems like the Iron Dome, as their deployment would cost the U.S. budget hundreds of billions, or even several trillion, dollars. However, the “Dome” concept is well-suited for protecting American enclaves outside the U.S., such as the island of Guam, located 3,000 km from Taiwan. In the event of armed aggression from China, Guam would serve as a key stronghold for U.S. air and naval presence in the region.  

Missile defense for Guam became relevant in the early 1990s when the collapse of the Soviet Union shifted American focus to new challenges, primarily North Korea and Saddam Hussein’s Iraq.

The Pacific island of Guam, covering a total area of 543.9 km², hosts Andersen Air Force Base and the Naval Base in Apra Harbor. In late 2024, to protect these facilities, the U.S. Missile Defense Agency (MDA) successfully tested a new missile defense system for Guam, called Aegis. This system is designed to intercept missiles during their midcourse phase, while they are still in space. To track missile threats, the U.S. Navy deployed the Army’s AN/TPY-6 surveillance and control radar station.

During last year’s tests, the Terminal High Altitude Area Defense (THAAD) system was also demonstrated. THAAD is designed to intercept ballistic missiles in the final phase of their flight, after they have re-entered Earth’s atmosphere.  

The last, but equally crucial, component of missile defense is the Patriot system, which has been in service with the U.S. Army since 1982. Despite its long operational history, it continues to demonstrate effective missile interception capabilities. This has been proven in Ukraine, where Patriot systems have been used to counter Russian missile attacks, including intercepting new types of maneuverable hypersonic missiles.  

Together, THAAD, Aegis, and Patriot form what is known as the Enhanced Integrated Air and Missile Defense System (EIAMD) for the island, providing comprehensive protection against nearly all known types of missile threats, including maneuverable hypersonic missiles. Guam serves as a successful example of missile defense deployment similar to Israel’s Iron Dome, but this effectiveness is only possible due to the limited geographic area.  

Despite its relatively high level of protection and the ability to track incoming missiles from all directions—critical for island-based missile defense—EIAMD remains a ground-based system. Although the Missile Defense Agency (MDA) claims that some aspects rely on Tranche 0 satellite tracking data, space itself is not directly integrated into the architecture. Additionally, it may take up to 10 years to fully deploy all components of EIAMD on Guam alone.  

Senior Pentagon officials are already aware that to counter the modern missile capabilities of adversaries, the U.S. military will require a comprehensive, multi-layered system for tracking and intercepting ballistic missiles. Such a system must include a space-based component, not only for missile tracking but also for intercepting them in space.

The possibility of space-based interceptors 

The executive order that established the “Golden Dome” explicitly indicates that the United States is considering the deployment of “hypersonic and ballistic space sensor layers, distributed space interceptors, expanded space-based fighter architectures, capabilities for pre-launch missile volley defense, non-kinetic missile defense capabilities, as well as lower- and terminal-phase interception capabilities.” 

For now, let’s focus on the potential deployment of space interceptors.  

The text of Trump’s January executive order strongly suggests that the U.S. is beginning to reconsider its stance on the moratorium against deploying conventional weapons in space. It is also important to highlight that the technical limitations that previously hindered the deployment of such weapons in orbit have been significantly addressed. This progress has made the prospect of space-based interceptors not only realistic but also much more affordable, thanks to new reusable rockets and the use of methane fuel, which have drastically reduced the cost of delivering payloads to orbit.  

The main obstacle remains the legal commitments the U.S. has undertaken under various international treaties that explicitly prohibit the deployment of weapons in orbit—chief among them, the 1967 Outer Space Treaty. According to some analysts, if the U.S. begins deploying space-based interceptors, it will set a precedent that could prompt symmetrical responses from the Russian and Chinese governments, leading to the development of their own space-based missile defense systems. However, one recent report on missile defense notes that such moves may already be in the works. The report states that “Russia has preserved and modernized its own missile defense system, originally designed to protect Moscow from a U.S. strike.”  

In any case, the reality the United States faces is that its strategic adversaries already possess next-generation missiles. The current American missile defense system is simply not capable of responding adequately to these threats.

It is also worth mentioning an alternative to conventional weapons in orbit: laser strike systems and beam weapons using directed streams of neutrally charged particles, which could leverage electromagnetic pulses to counter missile threats.  

The latest concepts for developing and deploying such systems in orbit date back to Donald Trump’s first term in 2018. At that time, Under Secretary of Defense for Research and Engineering Michael Griffin stated that such next-generation non-conventional space-based weapons for countering ballistic missiles could enter service with the United States in a few decades.  

In 1989 the U.S. experimented with a neutral particle beam (NPB) emitter. It was then discovered that a directed stream of neutral particles could be made narrow and powerful enough to disable ballistic missiles just after launch from their silos, submarines, or other launch sites.  

The key advantage of space-based interceptors is their ability to counter missile threats in the early stages of launch, during the rocket’s boost phase, which typically lasts 3–4 minutes. Due to the nature of the boost phase, a missile cannot maneuver (in the case of hypersonic missiles) or deploy decoys and countermeasures, which some ballistic and cruise missiles are capable of doing in the final stages of their flight.  

However, this early response capability is also the Achilles heel of space-based interceptors, as it leaves very little time for detection, verification, and counteraction. Even if early warning satellites classify a ballistic missile launch within 30 seconds, a space-based missile defense system would have only 150 to 210 seconds to track the exact trajectory and neutralize the target.  

Considering these factors, space-based ballistic missile interception systems must meet two main requirements: they must be numerous and positioned in low Earth orbit (LEO) at no higher than 600 km to ensure the necessary reaction speed.  

In his analysis of these countermeasure weapons, Todd Harrison, a senior fellow at the American Enterprise Institute (AEI), concluded that deploying a constellation of 1,900 space-based interceptors could cost the U.S. between $11 billion and $27 billion. Additionally, space-based interceptors are just one component of a complex and multi-layered global missile defense architecture, which in its entirety would require significantly larger budgetary investments.

The “Golden Dome’s” main obstacles

Apart from the high costs, the concept of an American “Golden Dome” faces numerous challenges. The Trump administration’s push to create a U.S. version of the Iron Dome appears questionable, as Israel’s missile defense system is fundamentally different from what the U.S. requires.  

While the original Iron Dome is primarily designed to intercept short-range rockets and artillery shells, the primary threat to the U.S. mainland comes from intercontinental ballistic missiles (ICBMs). These are fundamentally different threats that the Israeli missile defense system is simply not designed to counter. Additionally, hypersonic missiles, another major concern for the U.S., are currently not a threat to Israel, as Iran, Hamas, and Hezbollah do not possess them.  

It is also important to note that any missile defense system, whether ground-based, airborne, or space-based, faces challenges in countering large-scale missile salvos. Even the Israeli Iron Dome, which is the primary inspiration for the new American missile defense system, was unable to intercept the entire barrage of over 180 Iranian ballistic and cruise missiles, as well as drones, allowing some to penetrate Israeli airspace. No missile defense system is flawless, and there will always be a margin of error, with some missiles slipping through. However, in a potential conflict with nuclear-armed adversaries, even a single nuclear warhead getting through could have catastrophic consequences.  

A key challenge for the new missile defense system may be Trump’s ambition to develop it entirely from American-made components within the U.S. This would require billions in investments into industrial infrastructure, with some components needing to be built from scratch. Another obstacle is the need to train a highly skilled workforce capable of developing the system’s advanced components and sensors. Consequently, relocating the full production cycle to the U.S. is expected to drive up the system’s final cost.  

The integration of artificial intelligence (AI) into the future missile defense architecture is another crucial factor. In August 2024, the research division of General Dynamics Information Technology introduced a new tool called the Defense Operations Grid-Mesh Accelerator (DOGMA). This system can collect and process massive amounts of data from satellite observation sensors and ground stations to determine the fastest route for alerting the Missile Defense Command Center about incoming ballistic missiles or drones. GDIT claims that their AI-powered tool can also utilize commercial communication channels such as Amazon Web Services and Starlink. However, for this level of interoperability to function reliably, the U.S. must first establish a unified software standard that both military and civilian satellites will follow. Needless to say, not all commercial satellite companies are enthusiastic about this prospect.  

As we can see, the U.S. faces a truly historic challenge in building its next-generation missile defense system. Despite the hurdles, Trump’s directive firmly asserts the new administration’s commitment to ensuring “peace through strength.” Given the growing number of countries embracing a force-based approach to foreign policy, the U.S. has little choice but to continue investing heavily in strengthening its national security.