The U.S. territorial missile shield now being deployed in Alaska and California continues to consume the most funds by far of any program within the portfolio of the U.S. Missile Defense Agency (MDA), accounting for some $2.8 billion of the agency’s $9.3 billion budget request for 2007.

Overall, the request represents a significant increase — $1.6 billion — over the MDA’s 2006 funding level. Budget charts provided by the agency show funding going up next year for most of the major interceptor programs. Also included are funds to begin work on a new missile tracking satellite and for hardening the overall U.S. missile defense architecture against a nuclear attack, according to MDA briefing documents and a Defense Department official.

The budget for the main U.S. shield, known as the Ground Based Midcourse Defense System, would rise by about $400 million, or 16 percent, under the MDA’s 2007 spending plan. The Aegis sea-based interceptor program would see its budget rise by just under 10 percent, from $867 million this year to $947 million next year, budget documents show.

Speaking to reporters at a budget briefing Feb. 6, the Defense Department official said the MDA has scaled back its interceptor procurement plans in favor of developing new and improved versions and upgrading existing missile defense sites including Fort Greely, Alaska, and Vandenberg Air Force Base, Calif.

Among the interceptor-improvement programs under way is the Multiple Kill Vehicle, which would address the problem of decoys and other countermeasures by enabling a single Ground Based Midcourse interceptor to engage several targets in the same area. The MDA is requesting $165 million for that program next year, compared to an approved budget of $50 million in 2006.

Rick Lehner, an MDA spokesman, said in a written response to questions that the agency is still discussing the total number of interceptors it will buy for programs like the Ground Based Midcourse Defense System and the Aegis Ballistic Missile Defense System. Those numbers likely will be finalized by the time the agency submits detailed budget justification materials to Congress later in February, he said.

The 2007 budget includes funds for one intercept test of the Ground Based Midcourse Defense System and two of the Aegis system. Plans call for bringing more realism into the midcourse defense system test by giving system operators only a rough sense of when the target missile might launch, as opposed to a precise time, the Defense Department official said.

The MDA’s two main boost phase programs — so called because they are designed to shoot down missiles as they take off from the ground — are slated for some of the biggest funding increases next year, percentage wise.

Funding for the Airborne Laser, a modified Boeing 747 aircraft equipped with a high-power laser, would increase by 31 percent, from $455 million this year to $598 million in 2007, according to the budget briefing charts. MDA plans call for a demonstration in 2008 in which the Airborne Laser will attempt to shoot down a target missile.

The results of that test will help determine whether the MDA continues with the Airborne Laser or terminates it in favor of the Kinetic Energy Interceptor, the agency’s other main boost-phase program. The Kinetic Energy Interceptor, a ground-based high-speed rocket, would receive $386 million in 2007, some 91 percent more than the $202 million allocated this year, according to the MDA budget documents.

The MDA restructured the high-speed interceptor program last year to focus almost exclusively on an initial flight test in 2008 that will help determine its future, and the 2007 spending plan moves the system’s notional fielding date from 2012 to 2014, according to budget documents. The charts show program funding remaining relatively flat in 2008 but more than doubling in 2009.

Bucking the overall trend of funding increases is the Terminal High-Altitude Area Defense program, which would see its budget dip slightly in 2007, from $991 million to $942 million, the briefing charts show.

The MDA’s biggest unclassified space program remains the Space Tracking and Surveillance System, a series of experimental satellites that would track missiles during the midcourse phase of flight. Two experimental satellites are well along in development and scheduled for a flight demonstration around 2007. The budget for the program would increase from $228 million this year to $380 million in 2007, the budget charts show. Driving the proposed increase is $97 million to begin development of additional satellites that would launch around 2012 .

As was the case last year, the budget request contains no funding for space-based missile defenses, although the MDA’s briefing charts show $570 million being spent for that purpose from 2008 through 2011. The Defense Department official said that the notional plan presumes approval for deploying such systems following the appropriate policy debate.