Defense and aerospace giant Lockheed Martin Corp. of Bethesda, Md., is trying to drum up U.S. government interest in a system that would defend American territory against missiles launched from ships lurking offshore.

The U.S. Department of Defense is deploying a rudimentary system to protect the nation against intercontinental ballistic missiles (ICBMs), but there is no program under way to guard against sea-based threats. With approximately 20,000 kilometers of coastline, the United States is highly vulnerable to such an attack, according to David Kier, Lockheed Martin vice president and managing director of protection systems.

Approximately 75 percent of the U.S. population and 75 percent of U.S. military bases are located within 322 kilometers of a coast, putting them within range of missiles fired from offshore, Kier told reporters at a July 28 luncheon at the National Press Club here.

Short- and medium-range ballistic missiles are widely available throughout the world and are easy to conceal and launch from an innocuous looking ship, said Kier, a former deputy director of the U.S. National Reconnaissance Office. Cruise missiles are even easier to hide, less expensive and are about 10 times more accurate than ballistic rockets, he said.

For about $10 billion to $12 billion, Kier said, the United States could deploy a shield against such threats drawing on missile defense systems that are either in use today or well under development — in several cases by Lockheed Martin. The hardware in use today or ready for deployment includes theater missile defense systems such as the Patriot Advanced Capability 3 interceptor and the Aegis-ship-based tracking radars and Standard Missile 3 interceptors, he said.

Ballistic missiles launched near U.S. shores could be detected by the Space Based Infrared System, a series of missile warning satellites under development by Lockheed Martin Space Systems of Sunnyvale, Calif. Those satellites are supposed to begin replacing the Defense Support Program missile warning satellites in 2008 or 2009.

Cruise missile launches cannot be detected with the infrared satellites, but Kier said Lockheed Martin is working on a system that could do the job by measuring disruptions in FM radio frequency waves.

Other hardware that could contribute to a coastal missile defense system include unmanned aerial vehicles and a high-altitude airship under development by Lockheed Martin that would be able to dwell over areas for extended periods of time, Kier said.

Thad Madden, a spokesman for Lockheed Martin, said the various components of the architecture would be integrated and managed using the command-and-control system for the Ground Based Midcourse Defense system, the U.S. territorial ICBM shield.

Lockheed Martin designed its proposed coastal defense architecture on its own accord — the Pentagon has no program under way to address the threat and no immediate plans for one. But that could change if a congressional proposal to provide funding in 2006 for such an effort becomes law, an official with the U.S. Missile Defense Agency (MDA) said.

The House of Representatives included about $20 million for work on a coastal missile defense system in its version of the 2006 Defense Appropriations Act, which was passed June 20.

In the report accompanying the bill, members of the House Appropriations Committee said they have become “increasingly concerned” about offshore missile attacks and asked the MDA to conduct a comprehensive analysis of the threat and how to counter it. The lawmakers directed the MDA to give periodic updates on its findings to the committee.

“This analysis should consider deployment options that would protect significant population centers, use mature technologies, and include progressions for spiral technology upgrades that would enhance missile defense capabilities over time,” the report said.

The Senate Appropriations Committee has yet to mark up its version of the 2006 defense budget, and will not do so before Congress returns from its August recess in September.

Victoria Samson, a research analyst at the Center for Defense Information, a think tank here, said cruise missiles potentially could pose a significant threat to the U.S. homeland, but added that a nationwide interceptor network likely is unaffordable.

Samson noted that the Pentagon has spent roughly $92 billion to date on the national ICBM shield, and said Lockheed Martin likely is underestimating the price tag of its proposed coastal defense system. She pointed out that the Pentagon deployed over 1,000 Patriot interceptors to defend U.S. troops in Iraq, a far smaller area than the United States.

The United States could only afford to protect a few key areas of its territory against missiles launched from offshore, Samson said. Measures to stop the spread of missile technology to U.S. enemies are a far more sensible way to address the problem, she said.