Building an Iron Dome for America: Hope, Hype, & Hard Truths
The seemingly irresistible allure of ballistic missile defense
Good morning,
Earlier this week, President Trump signed an executive order titled "The Iron Dome for America." The executive order directs--among other things--the development and deployment of space-based interceptors capable of boost-phase intercept, development and deployment of other capabilities to defeat missile attacks prior to launch and in boost-phase, deployment of terminal-phase interceptors, and the development of non-kinetic capabilities defense.
Ballistic Missiles 101
Ballistic missiles are a type of missile that uses projectile motion to deliver warhead on a target.
Throw a ball up into the air (at an angle) and it will follow a ballistic trajectory until it lands. Throwing the ball higher and faster means it will travel further. Throw it hard enough and it will cross the Karman line and enter space briefly before falling back down to earth (but be careful, if you throw it TOO hard it will enter an orbit around the earth).
The parabolic shape that the ball takes from the time it is thrown until it lands is known as its ballistic trajectory.
Ballistic missiles follow the same principles, but instead of being thrown, they're boosted by rockets before falling back down to their target. And with enough force a ballistic missile can travel anywhere around the globe striking targets with great speeds and energy. Throw a nuclear warhead on that ballistic missile and you can further compound the destructive force of it.
A ballistic missile (and particularly intercontinental ballistic missiles or ICBMs, which are our primary concern) has three phases of flight along its trajectory. The first is the 'boost phase'. This is when the rocket engine is powering the missile, increasing speed and pushing it out of the atmosphere. In our ball-throwing analogy, this is the part of the ball's flight where the ball has not yet left the boy's hand. He's physically accelerating the ball, pushing it through the air. With missiles, the boost phase is of moderate duration, generally lasting several minutes.
Once the missile's engine cuts off and the missile has entered space, we consider the missile to be in its midcourse phase. During this phase, the missile flies at speeds up to 4 miles per second. Per second. We'll say that one more time: four miles per second. Despite that incredible speed, the midcourse phase is the longest phase and can last up to 20 minutes for an ICBM. As such, many active efforts to intercept a ballistic missile focus on the midcourse phase.
Eventually the warhead of the missile will reenter the earth's atmosphere, after which its considered to be in its terminal phase. As the missile falls down towards its target, it actually slows down to a still impressively quick 0.5 miles per second. Nevertheless, this phase is usually the shortest lasting only around a minute or two, before slamming into its target.
Early in the Cold War, the threat of annihilation from ICBMs prompted the doctrine of Mutually Assured Destruction, as if an enemy's ICBM launch could be detected, the 20-30 minutes from launch to terminus, allowed sufficient time for us to respond in kind. This created a sort of stand-off.
Today, space is easier to reach than ever before. There are over 100 space launch companies and agencies today and, as we'll show in a minute, if you can launch a spaceship, you can launch an ICBM. The list of countries with space launch capabilities includes the four countries that comprise the Axis of Autocracy: China, Russia, Iran, and North Korea. It's also quite possible to see other states and non-state actors develop this sort of technology in the coming years. For example, Yemen's Houthis have demonstrated short-range ballistic missile technology, aided by Iran. In other words, ICBMs and other ballistic missiles represent an increasing threat.
A brief history of Ballistic Missile Defense (BMD) in the United States
Since the first ballistic missiles, Germany's V-2, rained on London in the Second World War, we have sought ways to counter the threat posed by vertical attack. The Soviet's first nuclear detonation in 1949, and their launching in 1957 of the world's first ICBM and the Sputnik-1 satellite accelerated fears of missile attacks. The technology to launch an orbital spacecraft, it turns out, is the same as to launch an ICBM.
Back during the war, the British created the world's first integrated air and missile defense (IAMD or IAD) system, linking a large radar system known as Chain Home to specific defensive capabilities. Chain Home was a bistatic radar able to detect German aircraft and V-1 rockets (unlike the V-2, the V-1 was not a ballistic missile but rather a cruise missile). Once Chain Home detected inbound missiles or aircraft, fighter-interceptors around London could be scrambled to intercept the threat.
Following World War 2, the United states began a series of efforts to create ballistic missile defense programs including Project Thumper and Project Wizard. Unfortunately, these programs largely faltered, determining that the state-of-the-art currently lacked the necessary abilities to provide sufficiently early detection to allow intercept. They were ultimately abandoned with some of the technology absorbed into other programs.
One of those technologies actually helped solve the problem plaguing the two projects and would mature into the Ballistic Missile Early Warning System or BMEWS. BMEWS combined several radar capabilities and would stand guard along North America's northern front for more than 40 years. BMEWS and its complements and successors including PAVE PAWS, PARCS, and other ground based radars provided certain capabilities to detect and track ballistic missile threats at various stages of flight.
These ground-based radars have further been complemented by space-based detection and tracking capabilities. In the 1960s, the U.S. launched its Missile Defense Alarm System or MiDAS, although this constellation provided only a crude capability and would shortly be replaced by the Defense Support Program (DSP). While DSP satellites remain in orbit and continue operations, the Space-Based Infrared System (SBIRS) has replaced DSP as the primary space-based capability for early warning.
Once a missile has been identified and tracked, defensive systems must neutralize the missile. This can be accomplished either through a hit-to-kill or through a proximity hit with fragmentation. In a hit-to-kill system, one is literally shooting a bullet out of the sky. It uses the kinetic energy of the anti-ballistic missile (ABM) to destroy the ballistic missile. This is harder but for various reasons is preferred to fragmentation which can have unintended consequences including damaging other space craft.
Due to the difficulty involved in hit-to-kill systems, early ABM efforts focused on proximity kills. One of the earliest examples of this was the Nike-Zeus missile. Nike-Zeus was a nuclear tipped ABM that saw development beginning in the 1950s before President Kennedy canceled the program in 1963. The most recent attempt at creating an intercept missile is the Ground-based Midcourse Defense (GMD) missile, on which work continues today (more on the GMD in a few).
Of course, we cannot talk about the history of ballistic missile defense efforts without discussing President Reagan's Strategic Defense Initiative (SDI), also known as Star Wars, and President George W. Bush's National Missile Defense.
Star Wars
In his short tightly-written guidance in National Security Decision Directive 12 (NSDD 12), President Reagan directed a modernization of strategic defenses. This included a 'vigorous research and development program' on ballistic missile defense systems. Two years later, Reagan announced the Strategic Defense Initiative during a nationally televised broadcast. He immediately followed the announcement by signing NSDD 85, which helped explain Reagan's rationale for the program. By creating a ballistic missile defense program, he believed that we could reduce our reliance on retaliatory strike capabilities and mutually assured destruction--ultimately resulting in deescalating global tensions.
The Strategic Defense Initiative invested in a suite of research projects including a long-range interceptor missile (LRINT) also known as an extended-range interceptor missile (ERINT), employing a hit-to-kill capability. This missile eventually became the MIM-104 missile used in today's Patriot missile system. The Patriot saw its first operational success during the 1991 Operation Desert Storm when it intercepted an Iraqi Scud missile fired at Saudi Arabia. According to Army reports, the operational effectiveness of the Patriot then was around 80%. That number is unlikely, and an independent research effort concluded that 'the best evidence indicated that the Patriot hit between zero and four of the 44 Scuds it engaged.'
Regardless of the Patriot's performance more than 30 years ago, it has dramatically improved today and become an indispensable component of air and missile defense for the United States and many Allies and partners.
Star Wars included several theoretical space-based kinetic capabilities including Brilliant Pebbles, which amounted to a proliferated constellation of IR-seeking missiles. By having a constellation of these weapons, the Brilliant Pebbles concept would ensure sufficient numbers over the Soviet Union at any given time that they could destroy Soviet ballistic missiles during the boost phase.
In addition to the kinetic capabilities that have had long-term tangible benefits to our air and missile defense programs, the SDI also prioritized research into directed energy weapons (DEWs)--and particularly space-based DEWs. Perhaps the most controversial of these was the X-ray laser program called Project Excalibur that involved a nuclear detonation in space to create a large number of X-rays which the weapon theoretically would focus at multiple ballistic missiles at once as coherent beams by pushing the X-rays through tunnels of metal rods.
President George H.W. Bush proposed cutting SDI spending almost immediately upon succeeding Reagan. He would continue to scale back the program throughout his tenure, accelerating that scale-back after the end of the Cold War. Rather than seeking a defense against thousands of ballistic missiles, Bush wanted to reorient towards the defense against a limited strike capability of up to 200 missiles. In an era of exuberant optimism and euphoria following the nearly 50-year Cold War, defense funding was acceleratingly reduced. The symbolic end of SDI came in 1993 under President Clinton, when the Strategic Defense Initiative Organization--created under Reagan--reverted to its previous name of the Ballistic Missile Defense Organization.
National Missile Defense
America woke from its euphoria on September 11, 2001. We remembered that while the Cold War was over, the world was not entirely peaceful. Adversaries could still reach us in the Homeland whether through crude means such as hijacking airplanes or through technologically sophisticated means such as ballistic missiles.
President George W. Bush sought to reinvigorate homeland defense through a sophisticated, nation-wide antiballistic missile regime. To that end, he withdrew the country from the ABM Treaty, which put restrictions on the development of such a nation-wide system, and redesignated efforts as 'National Missile Defense.'
National Missile Defense was largely based on the Ground-Based Midcourse Defense (GMD) program, on which development continues. The GMD system includes numerous sub-systems including ground- and space-based radar to detect and track ballistic missiles and the ground-based interceptor (GBI), the actual ABM weapon. According to the Missile Defense agency, there are 44 interceptors across the United States at present. It's also important to highlight that the GBI has had questionable success in intercepting. Over the length of the GBI program, the Missile Defense Agency has conducted 21 intercept tests with 14 successful kills (57%). Over time, it appears, that success has come more often than not.
Those numbers statistically can increase by firing multiple interceptors per ballistic missile; roughly, firing four interceptors gives a 97% probability of successful intercept. Unfortunately, we're still limited to the 44 interceptors we have available. So, if a threat country were to launch 11 ballistic missiles at us, we'd have only a 26% chance of intercepting all 11 of them and we'd have exhausted all of our interceptors. Even a table at Vegas has better odds.
Next Generation Interceptor (NGI)
Let's bring it back to President Trump's efforts. In 2019, during his first administration, the Missile Defense Agency reportedly floated a classified draft RFP to industry for a next-generation interceptor. The following year, the MDA released the actual RFP. The FY25 NDAA authorized $1.7B for continued RDT&E of the NGI this year. It's yet to be seen how much Congress will actually appropriate, though. We expect procurement of the improved system to begin FY27-28 at a cost of roughly $0.5B per interceptor.
The Government Accountability Office (GAO) has already taken several critical looks at the program finding for example that in FY22, the Missile Defense Agency executed only 17 of 32 planned tests (flight, ground, and cyber tests).
Persistent Challenges with BMD
All of this is to say that ballistic missile defense is extremely hard. We do a pretty good job at this point of knowing if an adversary is launching a ballistic missile thanks to things like the SBIRS and DSP. We do a fairly good job of tracking it in flight. We do okay at discriminating specific threats in clutter clouds during flight. At best, we do a mediocre job of intercepting these missiles during their midcourse or terminal phases--and that's before our adversaries further complicate targeting through the use of hypersonic glide vehicles (HGVs), maneuverable reentry vehicles (MaRVs), multiple independent reentry vehicles (MIRVs), false warheads, midcourse maneuvers, et al. And we're failing at doing these things at reasonable costs.
And we're still faced with the challenge of having enough interceptors. We highlighted earlier that the MDA acknowledges 44 interceptors. We also explained that if we shot all of those at 11 missiles, it's quite probable that at least one ballistic missile would sneak through our defenses. The reality is that we have a pitiful number of interceptors compared to the size of our adversaries' arsenals. According to a 2023 DoD report, China likely had 350 ICBM missiles (and growing rapidly). At a 4:1 ratio of interceptors to missiles, we'd require 1,400 interceptors at a cost of about $700B--almost the entirety of our defense budget.
With this many interceptors, we'd have 0.000516% chance of stopping every ICBM launched. If we double our interceptors we increase our odds significantly to 66% chance of stopping them all. To get to those odds up over 90%, we'd need 10 interceptors per missile fired. Of course, that would cost $1.75T (yes TRILLION). Also, with that many things blowing up in space, we'd almost certainly create the Kessler Syndrome--a catastrophic cascade of space debris making LEO completely unusable for centuries.
Attacking ballistic missiles midcourse, then, is expensive and impractical. What if we could stop them before they got to space?
Intercepting missiles earlier--during the boost phase or prior to launch--seems a logical step for the new administration to attempt. However, this approach too is fraught with challenges and risks. Resurrecting a program similar to Brilliant Pebbles is technically feasible and would cost much less today than it would have in the 80s. The New Space Economy has lowered the cost of launch to a reasonable figure that would allow the creation of a constellation of Brilliant Pebble systems.
The biggest problem with boost-phase intercepts and pre-launch intercepts is discrimination of intent. SBIRS and DSP can detect a launch, easily enough. The image below is the only publicly released SBIRS image released to Aviation Week and shows a Delta IV rocket launch. The plume is readily visible (noted by yellow arrow in upper right side of photo) as it travels against the backdrop of Earth.
Deciding that the launch was a Delta IV was relatively easy as the launch was anticipated and the orbit of its payload was known in advance. But with a boost-phase intercept capability, avoiding false-positives becomes critical to not interfere with another country's space launch program or their own testing of weapons. In other words, boost-phase intercept really only makes sense if you're already in a conflict that hasn't moved into space.
Conclusion
We've said it many times before. Space is hard. Defense against space warfare is hard. Ballistic missile defense is hard AND costly.
We're not suggesting that it's not worth pursuing.
When budget fights come (and they will come), trying to justify hundreds of billions or trillions of dollars on an umbrella that may still not work will be difficult to justify.
The Department must prioritize its investments. For BMD, it should prioritize:
Hardening and building resilient critical infrastructure in the Homeland
Providing terminal-phase intercept capabilities over critical population centers
Exploration and RDT&E of non-kinetic capabilities and advancement of DEWs
Improved understanding of adversary decision making, and of course
Credible deterrence
The whole-of-government must prioritize:
International cooperation and continued efforts to limit proliferation of critical weapons technologies
Ensuring bilateral and multilateral communications channels with adversaries
Creating intelligence collection programs that better illuminate adversaries' intentions
Developing space debris mitigation plans and technologies to ensure future access
Now, without any more ado, let’s dig into the rest of the news around space this week.
News Headlines:
Hegseth highlights ‘Iron Dome for America’, other first priorities as new SecDef (DS)
Musk speaks at Germany’s AfD campaign launch as thousands protest far-right party (CNN)
Sweden seizes vessel suspected of ‘sabotage’ after undersea data cable rupture in Baltic Sea (AP)
US tech stocks steady after DeepSeek AI app shock (BBC)
Eric Schmidt says DeepSeek marks a ‘turning point’ for the global AI race (TC)
Satellites:
Launches:
Upcoming Launches:
Space News:
U.S. startup to establish first solar-powered data center on Moon in February (IE)
Space Force forecasts $2.3B in commercial satellite services contracts (SN)
NRO, Navy launch experimental Otter CubeSat (DS)
Space Force still mapping out strategy for in-orbit logistics and satellite services (SN)
Astronomers seek a global ban on space advertising (SN)
VC firm Space Capital predicts dramatic shakeup of industry (SN)
Intuitive Machines delivers second lunar mission lander to Cape Canaveral (GN)
Google Maps will rename Gulf of Mexico as Gulf of America in U.S. (AP)
Satellite images show China building huge secret fusion research facility: analysts (IND)
Firefly pressing ahead with Alpha launches from Wallops and Sweden (SN)
Array Labs, Raytheon, Umbra form partnership focused on 3D mapping from space (SN)
Sen unveils 4k video livestream feeds of Earth and ISS docking port (SN)
Foreign Space News
ESA enlists Thales Alenia Space for mission to Venus (SN)
China launches fourth batch of Thousand Sails megaconstellation satellites (SN)
Distant electromagnetic fluctuations known as ‘chorus waves’ found by China-led study sound alarms for space travel (SCMP)
China’s Chang’e-8 lunar mission to include first Chinese private sector tech firms’ robotics (SCMP)
China embraces commercial participation in moon mission for the first time (SN)
Astroscale secures Japanese contract for in-space refueling (VS)
Deal Flow:
VC
Chinese launch startup Nayuta Space secures early funding from Quanxin Investments for fully reusable rocket plan (SN)
PE / M&A / Exits / Other
AST SpaceMobile raises $400 million in convertible debt to accelerate direct-to-smartphone plans (SN)
Voyager Technologies aims for a multibillion valuation in its IPO filing (TC)
Karman Space & Defense also filed for an IPO (BBG)
Opportunities
The Air Force is conducting market research on potential vendors to assist with end-unit encryption for protected tactical satellite communications (SAM)
Editor’s Picks
Ilaria Cinelli explores AI’s impact on humans’ roles in space exploration.
Lighter Side:
Keep Building,
BOF