WASHINGTON — A senior U.S. Senate Democrat who will have a primary role in crafting next year’s Pentagon spending bill said March 19 that in the missile defense arena, deployment-ready systems will take priority over next-generation capabilities.

Sen. Daniel Inouye (Hawaii), chairman of the Senate Appropriations defense subcommittee, identified three programs as “pillars” of the emerging U.S. shield: The Ground-based Midcourse Defense, Aegis sea-based, and Terminal -High Altitude Area Defense systems. All three programs have had success in testing recently and now are being deployed.

In a keynote address to the 5th annual U.S. Missile Defense Conference, Inouye identified himself as a strong supporter of missile defense, but said sustaining the levels of spending this activity has seen in recent years will be challenging given other U.S. military priorities. Among these are the U.S.-led wars in Iraq and Afghanistan and overall military modernization.

The U.S. Missile Defense Agency (MDA), Inouye said, should focus on getting the near-term systems into the field before moving ahead with next-generation technologies.

U.S. Air Force Lt. Gen. Henry “Trey” Obering, the MDA director, said this same emphasis is reflected in the agency’s 2008 budget request, which at $8.9 billion is some $500 million less than the MDA anticipated at this time last year. Of that total, he said 75 percent is allocated to the near-term systems, with next-generation systems accounting for the rest.

The MDA’s futuristic programs include the Airborne Laser, a modified Boeing 747 aircraft designed to shoot down missiles as they lift off; the Kinetic Energy Interceptor, a high-speed rocket touted for its versatility but whose role in the architecture is unclear; and the Multiple Kill Vehicle, which would address the problem of discriminating between warheads and decoys by destroying both .

Speaking at the conference, Obering said there is bipartisan support in Congress for missile defense but that there still is potential for significant reductions to the MDA’s budget request. One of the agency’s biggest challenges is getting the word out to both the Congress and the public about why the United States is better off with a missile defense capability, he said.

Democrats, who swept into the majority of both houses of Congress in November, are widely perceived as less supportive of missile defense programs than their Republican counterparts.

“Anytime you have change there is concern,” acknowledged David Kier, vice president of advanced concepts/protection at Lockheed Martin Corp. of Bethesda, Md., which has major roles in both near- and longer-term missile defense programs. Kier, speaking with reporters during a luncheon hosted by Lockheed Martin, said there has to be research and development into next-generation systems because the missile threat “is not going to stand still — it’s going to evolve.”

Michael Trotsky, vice president of air and missile defense at Lockheed Martin Missiles and Fire Control of Dallas, said Democrats are focused on the performance of existing systems and that Lockheed Martin’s missile defense portfolio is weighted toward those that are being fielded. But Lockheed Martin is prime contractor on the Multiple Kill Vehicle and also has a significant role in the Airborne Laser program.

Trotsky acknowledged concerns about Multiple Kill Vehicle. Congress cut $21 million from the MDA’s $165 million request for the program in 2007. The MDA is requesting $271 million for the Multiple Kill Vehicle next year, and anticipates the program’s budget will climb steadily to $843 billion by 2013.

Obering said the MDA hopes to conduct the first integrated flight test of the Multiple Kill Vehicle in 2013, and begin fielding the system around 2017.

Hover tests of the mother ship that would carry the independently targetable kill vehicles into space could begin in 2008 or 2009 at the U.S. National Hover Test Facility at Edwards Air Force Base, Calif., said Douglas Graham, vice president of advanced programs in the Missile Defense Systems unit of Lockheed Martin Missiles and Space of Sunnyvale, Calif.