“They’re not estimating what we’re building,” Guetlein said during an event hosted by defense technology and space publications Tectonic and Payload. “It’s as simple as that.”
The CBO released its estimate on May 12, basing its analysis on a January 2025 executive order by President Donald Trump that directed the Pentagon to develop an advanced, layered missile defense shield for the United States. The report described the proposed systems as a “notional national missile defense” architecture, citing limited public information about the program.
Guetlein said the CBO assumptions were based on concepts from the early 2000s that were designed for “a different fight.” He said those earlier concepts focused on point defense of limited areas rather than the broader regional and homeland defense mission intended for Golden Dome.
“That is not what we need for the homeland,” Guetlein said. “In a regional defense, there’s a different architecture.”
“And you can’t just take what we’ve done in the past and multiply it forward or you’re going to get large numbers like CBO got,” he added.
The CBO estimate is about seven times higher than the Defense Department’s own projection of $185 billion over 10 years. Guetlein said the limited amount of public detail about Golden Dome is linked to security and classification concerns, but added that the CBO did not consult the program office before publishing its estimate.
The CBO’s notional architecture included four interceptor layers: a space-based constellation, two wide-area surface layers and a regional sector layer. The largest projected cost was the space-based interceptor constellation, which the CBO estimated at $743 billion over 20 years, or about 60 percent of the total cost.
The space-based element in the CBO model assumed 7,800 satellites designed to intercept near-simultaneous intercontinental ballistic missile launches and hypersonic glide vehicle threats. The report estimated each satellite carrying a space-based interceptor would cost $22 million and have a five-year service life.
Guetlein has told lawmakers that space-based interceptors are not guaranteed to be included in the final Golden Dome architecture. He said the Pentagon would not pursue the technology unless it is affordable and scalable.
During the event, Guetlein said the CBO’s assumed space-based interceptor costs did not meet the program’s affordability targets. He said the Defense Department is pressing industry to develop more innovative and lower-cost solutions.
“That’s a signal to industry that says you need to simplify the solution,” Guetlein said. “You need to think innovatively about the requirements.”
Guetlein said the space industry is responding to the challenge. The Space Force has awarded 20 contracts worth up to $3.2 billion to 12 companies since last year to develop space-based interceptor capabilities, with integration into Golden Dome expected to begin in 2028.
“I believe that our industrial base can scale this all,” Guetlein said. “And I believe the innovation that I’m seeing coming out of AI, advanced processing, advanced manufacturing, 3D manufacturing, etc.—I think they’re going to figure out how to do it.”
Source: Air & Space Forces Magazine.
