Pentagon looking at 'monster' challenges in creating Golden Dome missile defense system

President Donald Trump's executive order outlining plans for a Golden Dome missile defense system to protect the U.S. from attacks pose "monster challenges" for the Pentagon.

The Office of the Undersecretary of Defense for Acquisition and Sustainment is working with the Missile Defense Agency and the military services on the project, said Steven Morani, who is performing the duties of undersecretary of defense for acquisition and sustainment at the McAleese Defense Programs Conference in Washington.

"Consistent with protecting the homeland and per President Trump's [executive order], we're working with the industrial base and [through] supply chain challenges associated with standing up the Golden Dome," Morani said.

In the 1980s, President Ronald Reagan wanted to build an air defense system, but technology wasn't available. Morani said the challenge would be formidable and require a lot of teamwork.

"This is like the monster systems engineering problem. This is the monster integration problem," he said. "This is going to be layers of architecture working together at all group level elevations … to protect the United States … so we're going to need all the services and agencies that do this kind of work to step up."

Some skeptics say the technology needed to protect a land mass the size of the U.S. still isn't ready. Israel's Iron Dome system works only against short-range rockets fired at a country the size of New Jersey. The system Trump envisions would protect the much larger U.S. using multiple layers of defense against a range of potential attacks.

Joe Cirincione, a national security analyst with Defense One, estimated that creating an Iron Dome for America would cost $2.5 trillion.

"Because Iron Dome is designed to intercept short-range rockets, not intercontinental ballistic missiles," he wrote. "Each Iron Dome system can defend an area of roughly 150 square miles. We would need to deploy more than 24,700 Iron Dome batteries to defend the 3.7 million square miles of the continental United States. At $100 million per battery, that would be approximately $2,470,000,000,000."

Cirincione noted that "it is technically impossible to build a system that can protect the United States from ballistic missile attack."

Two experts on security issues, Stephen J. Cimbala and Lawrence J. Korb, wrote in the nonprofit "Bulletin of the Atomic Scientists" that Trump's plan has "serious technology" flaws.

"The Trump administration's ambitious plans for nationwide defenses deserve serious scrutiny about whether they are feasible – from the standpoint of available and foreseeable technology and cost – and desirable, from the standpoint of deterrence stability," they wrote.

Nearly every president since Ronald Reagan has discussed some sort of missile defense system for the U.S. Reagan proposed the "Star Wars" system. In 1992, the U.S. Government Accountability Office concluded a proposed space-based interceptor system known as "Brilliant Pebbles" was based on immature simulations that "use many unproven assumptions." Some such projects cost billions and were eventually scrapped.