BOSTON — Several large aerospace firms are responding to a U.S. Missile Defense Agency (MDA) solicitation that could lead to a new prime contract for the U.S. missile shield, and one, Northrop Grumman, has indicated it will challenge Boeing for the lead role.

Boeing Missile Defense Systems of Arlington, Va.,

has served as prime contractor for the Ground Based Midcourse Defense System (GMD) since 1998, but the MDA, in a request for information issued Nov. 20, said it is considering different options for the program. These include awarding a new prime contract structured similar to Boeing’s or, more likely, breaking the work in to separate components: one for advanced development and one for maintenance and logistics.

Marynoele Benson, a Northrop Grumman spokeswoman, said in a written response to questions Dec. 13 that the company has the systems integration and missile defense experience “to take on a leadership role in all follow-on GMD efforts.” Northrop Grumman Mission Systems of Reston, Va., will lead a corporate-wide response to the request for information, she said.

Scott Fancher, vice president and general manager of Boeing Missile Defense Systems, said in a written response to questions Nov. 30 that the company planned to respond to the request for information and has unique expertise gained through its work thus far as GMD prime contractor. The GMD system includes interceptors, ground- and sea-based sensors, and a complex command and control system.

noted that Boeing had recently received an “exceptional” rating from the MDA following an evaluation of its work on the GMD program.

In a news release Dec. 12,

Northrop Grumman

refers to its own

experience as a prime contractor on “numerous large, complex weapons systems for the U.S. government.

” In missile defense, Northrop Grumman is

prime contractor for the Space Tracking and Surveillance System satellites and Kinetic Energy Interceptor, the release noted, adding that the company also runs

the Missile Defense Integration and Operations Center in Colorado Springs, Colo., which handles tasks including research, analysis and war games for MDA.

“Our experience integrating large, sophisticated weapons systems ranges from missile defense to ICBMs to nuclear aircraft carriers,” Jerry Agee, corporate executive for missile defense and president of Northrop Grumman Mission Systems, said in the Dec. 12 news release. “Northrop Grumman intends to bring its strong portfolio to bear on this critical missile defense program and demonstrate that the seamless delivery of an integrated missile defense system – optimized for performance and ready when needed – is within MDA’s grasp.”

Raytheon Co. of Waltham, Mass., also plans to respond to the request for information with input from several sectors of the company, according to Guy Shields, a company spokesman. Shields declined to say whether Raytheon would seek the prime contractor role.

Shields noted in a written response to questions

Dec. 13 that Raytheon has a “great understanding of the GMD system,” having built

the kill vehicles for the

interceptors and most of the tracking sensors used by the system.

Lynn Fisher, a spokeswoman for Lockheed Martin Space Systems of Sunnyvale, Calif., said in a written response to questions Dec. 12 that the company does not announce competitive intentions as a matter of policy, but noted the “GMD follow-on effort would provide a natural application of our talents and capabilities.”

Responses to the MDA request for information are due Dec. 31.