On October 24, 2024, former NASA Administrator Daniel S. Goldin joined us to applaud Elon Musk's SpaceX returning its 233-foot-tall booster to its launch tower, extending Ronald Reagan's Strategic Defense Initiative (SDI) Single Stage-Rocket-Technology (SSRT), demonstrated with NASA support.
We urge that President Trump's "Golden Dome" Initiative leverage commercial space technology and realize another SDI vision, a global space-based defense for Americans, our friends and allies. Elon's DOGE efforts should assess current DoD efforts and consider how current commercially available technology can provide significant cost savings.
Recent debates on space-based missile defense have alleged unfavorable technical feasibility and cost, but these factors were favorably demonstrated three decades ag0. And ignored continuing trends in aerospace economics for commercially based designs promise more favorable shifts in that calculus.
A modern "Brilliant Pebbles" — small, autonomous interceptors — could destroy ballistic missiles, beginning in their boost phase. Such a "Golden Dome" would be much cheaper and more cost-effective than proliferating traditional ground-based interceptors to protect us and our allies.
Three factors drive near-term advantages: Dramatically reduced launch costs, commercial manufacturing breakthroughs, and lightweight space hardware innovation—all illustrated by the well reported SmallSat and CubeSat revolution.
Weight Drives Cost: The Physics of Efficiency: Ground-based interceptors like the $111 million massive Next Generation Interceptor (NGI) or $70 million Ground-Based Interceptor (GBI) weigh thousands of pounds and require complex infrastructure. Space-Based Brilliant Pebbles would weigh about 100 pounds each, including self-contained propulsion, sensors, and guidance systems. This weight disparity directly impacts cost because of:
1. Launch economics: SpaceX's Falcon 9 has reduced launch costs by an order-of-magnitude, with internal costs as low as $17 million per flight. The impending Starship system aims for under $100/lbs. and another order-of-magnitude reduction, while achieving full reusability and unprecedented payload capacity.
Deployment and maintenance of such space-based systems will be far cheaper than the 1990's Brilliant Pebbles, for which there were then no developmental "showstoppers" as validated by numerous reviews, including by the 1989 JASON, a vaunted group of the nation's physicists and technologists.
2. Manufacturing and basing complexity: Large ground-based interceptors have dry weights up to 100 times greater and require expensive materials and precision engineering to survive atmospheric stresses. Many ground- and sea-based assets would be needed to protect the entire United States, its territories and allies.
Even given greater space-based system complexity, deploying and maintaining ground-based interceptors will be much more expensive for protecting a major Earth-surface area. Just a 100:1 mass advantage of space-based systems creates an insurmountable advantage, and a much greater advantage is possible.
The Starlink Playbook — Scaling Hardware Innovation: Amazon's upcoming Kuiper constellation and SpaceX's deployed Starlink demonstrate how commercial practices slash costs:
• SmallSat and CubeSat leverage: Both these and other low-cost constellations benefit from decades of corporate and university investment in small low-cost satellites.
• Mass production: Automated manufacturing of standardized components.
• Radiation-hardened commercial parts: Replacing custom aerospace-grade hardware with high-volume commercially available alternatives.
• Rapid iteration: Frequent design updates informed by real-world performance.
Similar emerging advances in low-cost orbit transfer vehicles with intrinsic rapid maneuver capabilities (e.g., Impulse Space, New Frontier Aerospace, etc.) further reduce costs by enabling precise orbital placement of space-based interceptors, ongoing constellation maintenance, and safe end-of-life deorbit. Very low unit manufacturing costs, routine maintenance, and ultra low-cost launch can enable deployment of larger rapid-maneuver spacecraft than were Brilliant Pebbles, and cost far less than ground- and sea-based interceptor systems, while offering a path to augmenting directed energy systems as that technology matures.
Countering Myths About Space-Based Systems: Critics argue space systems are inherently fragile or prohibitively complex, but studies three decades ago suggested otherwise and modern innovations and demonstrations also rebut these claims:
• Proven hardware: In the early 1990s, interceptor technology was still in development. Today, U.S. and foreign missile and space systems can produce over 30,000 mph closing speeds.
• Survivability: Distributed constellations of thousands of interceptors are far harder to disable than easily targeted fixed ground- or sea-based assets.
• Autonomy: Onboard sensors and AI-enabled tracking (pioneered by Starlink's collision-avoidance systems) minimize reliance on vulnerable ground stations.
• Maintenance: Emerging orbit transfer vehicles and advances in in-orbit servicing and modular design enable lifetime extensions and ongoing maintenance without costly human intervention, and offer a bridge to develop, deploy and maintain larger "speed-of-light" laser defenses.
The Speed Advantage: Any fighter pilot will tell you that speed confers a significant advantage in a dog fight. Space-Based Interceptors start with orbital velocities of approximately Mach 25.
As SDI demonstrated in the early 1990s, such interceptors can reach into the upper atmosphere, enabling boost, terminal and mid-course missile interceptions . . . and interception of hypersonic weapons in the upper atmosphere. Shaping and protecting the kinetic kill weapon can provide greater atmospheric reach.
Such defenses based in space are more effective than other basing modes at stopping incoming missiles, launched by a terrorist organization or a peer or near-peer nation.
The Strategic Dividend: Transitioning to space-basing is actually an economic imperative. Ground systems like the $18 billion NGI program hemorrhage funds for limited capability.
At a fraction of that cost, a space-based system leveraging commercial launch systems and spacecraft could involve thousands of interceptors—to neutralize conventional missiles and emerging threats, e.g., hypersonic weapons, that evade traditional ground-based systems.
The path forward is clear: Leverage the cost revolution in commercial space to build defenses that are lighter, smarter, and exponentially more affordable. Done right, space-based defenses will cost less than the patchwork of missile defenses employed today.
As launch costs trend toward $100/lb and manufacturing mimics consumer electronics, clinging to ground-based interceptors is a disservice to our national security. Elon, please help!
Ambassador Henry F. Cooper was the third SDI Director and Jess Sponable was the SDI DC-X Clipper Graham Program Manager and subsequently served at the Air Force Research Laboratory and Defense Advanced Research Projects Agency. Read Ambassador Cooper's Reports — Here.