A U.S. Senate panel recommended adding $50 million to the Pentagon’s 2010 budget request for the nation’s primary strategic missile shield to keep interceptor missile production lines open through next year.

The Senate Appropriations Committee, in releasing its proposed 2010 Defense Appropriations bill Sept. 10, recommended funding the Ground-based Midcourse Defense (GMD) system at $1.03 billion next year and purchasing seven more interceptors than currently planned.

Until this year, the GMD system was to have 44 interceptors in silos in Alaska and California. The Missile Defense Agency (MDA) reduced that number to 30 with its 2010 budget request, citing a threat that was advancing more slowly than anticipated. The agency still planned to buy 44 interceptors, but 14 of them would be kept in storage to replace missiles fired in testing and those that needed refurbishment.

The Senate committee’s decision to add funding to begin buying seven additional interceptors, for a total of 51, was informed by a new Integrated Master Test Plan that MDA submitted to Congress well after its budget request was unveiled, according to the report accompanying the bill.

The lawmakers also added $57.6 million to the MDA’s budget request to purchase six more Raytheon-built Standard Missile-3 interceptors and an additional $35 million for research and development of future versions of the missile. The panel did not include any money for the Kinetic Energy Interceptor program, which the MDA elected to terminate but which was funded at $80 million in the House version of the 2010 Defense Appropriations bill.

The Senate panel trimmed the MDA’s request for tests and targets by $188.1 million, to $778.7 million. This included a $37 million cut that would eliminate the two dedicated targets the agency planned to buy to test its Space Tracking and Surveillance System demonstration satellites that will launch in October. The panel noted that the demonstration satellites are based on old hardware that will not resemble the new space-based missile tracking system the MDA hopes to develop, and said the spacecraft can be adequately tested in coordination with tests of other ballistic missile defense systems.