国会预算办公室-发射成本降低对先前天基助推段导弹防御估计的影响（英）-2025.5_7页_958kb

CONGRESSIONAL BUDGET OFFICE
Phillip L. Swagel, Director
U.S. Congress
Washington, DC 20515

Re: Effects of Lower Launch Costs on Previous Estimates for Space-Based, Boost-Phase Missile Defense

Summary

This report by the Congressional Budget Office (CBO) assesses the impact of reduced launch costs on the estimated deployment and operating costs for space-based interceptor (SBI) constellations, previously analyzed by CBO (2004) and National Research Council (NRC, 2012). The report provides updated cost estimates based on significantly lower launch costs (approximately $1,200 per pound) compared to earlier assumptions ($9,800 - $10,600 per pound).

Key Findings

1. Cost Reduction from Launch Costs: Decreases in launch costs alone could reduce the 20-year cost estimates for SBI constellations by 30% to 40%. For the lowest-cost alternative examined, the total estimated cost over 20 years would decrease from $264 billion to $161 billion (in 2025 dollars). For the highest-cost alternative, it would fall from $831 billion to $542 billion.
2. Reduced Impact with Even Lower Costs: A launch cost as low as $1,200 per pound would reduce the launch-related portion of total costs to less than 10% of the total constellation cost, down from around 40% in previous estimates. Further reductions in launch costs would have limited overall impact due to weight savings and other major cost drivers.
3. Recent Threat Changes: Lower launch costs do not negate significant increases in required constellation size and cost driven by recent changes:
   • North Korea's Missiles: North Korea has significantly increased the number and sophistication of its ICBMs, potentially exceeding the threat sizes previously considered, which increased the required interceptor count and cost proportionally.
   • Expanded Defense Mandate: President Biden's "Iron Dome for America" executive order (EO 14186) expands the SBI mission to counter threats from peer/near-peer adversaries (e.g., China, Russia) in addition to regional adversaries. This would require vastly larger SBI constellations to cover greater geographical areas and counter stronger, more sophisticated threats, significantly increasing costs.
   • Countermeasures: Peer adversaries like China and Russia have capabilities to evade SBI defences (e.g., countermeasures, ASATs), potentially necessitating larger constellations for effective defence.
4. Competing Factors: While launch costs are a major factor, design choices (weight vs. countermeasure survivability), required performance, threat sophistication, and operational requirements are also dominant cost drivers.

Conclusions

Lower launch costs significantly reduce the cost of deploying and operating SBI constellations. However, recent operational requirements, driven by advances in adversary missiles and a broader national security strategy as defined in the "Iron Dome for America" executive order, likely necessitate larger and more capable systems, offsetting the savings from lower launch costs. Therefore, while lower launch costs make SBIs more economically viable, the decision to deploy them remains intertwined with evolving strategic threats and policy objectives.