WASHINGTON — The push in the U.S. House of Representatives for an early start on a third missile interceptor site on U.S. territory is meeting opposition in the Senate, which is recommending an alternative that features additional sensors to better discriminate between incoming warheads and decoys.

In marking up its version of the 2014 defense authorization bill June 14, the Senate Armed Services Committee recommended investing $30 million in additional X-band radars or other sensors to track incoming missiles, according to a press release issued by the committee. 

“This addresses the highest future investment priority identified by the Missile Defense Agency and the warfighter community for improving our homeland missile defense,” the committee said.

Overall, the Senate bill recommends $9.3 billion for missile defense programs, a $150 million increase over U.S. President Barack Obama’s request. The Senate bill directs the Pentagon to deliver to Congress a report on the merits of options for enhancing the U.S. territorial shield, including the third interceptor site, according to the press release, which makes no mention of funding for the so-called third site.

At a missile defense seminar here June 25, Robert Soofer, a staffer for the Senate Armed Services Committee, said the Obama administration and many in the Democrat-controlled Senate believe it may be more cost effective to invest in target discrimination capabilities than a third interceptor site, which he said would cost around $3 billion. But Soofer, who advises Republicans, noted that the administration did not seek funding for additional sensor capabilities in its 2014 budget request. 

Soofer said the Senate committee markup helps frame the upcoming debate over the third interceptor site, which likely would be located near the nation’s East Coast. The current U.S. territorial shield features interceptor fields in California and Alaska, and the Obama administration in March announced plans to beef up the latter site.

At the White House’s direction, the Missile Defense Agency (MDA) is studying options for the third site, but the Republican-led House would like to see it built sooner rather than later. Although U.S. Navy Vice Adm. James Syring, the MDA’s director, has said funding for the third site is not needed next year, the House armed services and appropriations committees have recommended providing $170 million and $70 million for that activity, respectively.

“They all recognize the value of an East Coast site,” Soofer said of Senate lawmakers on both sides of the aisle. “The question is do you want to spend an extra $3 billion over five or six years.” 

The Senate Appropriations Committee has yet to draft a spending bill for next year. House and Senate conferees are expected to meet late this summer or early in the fall to hash out differences in their respective defense authorization and appropriations bills.

Also at the discussion, titled “Defending the Homeland: The Role of Missile Defense,” panelists bemoaned the Obama’s administration’s apparent lack of interest in space-based missile defenses. Recent studies have dismissed space-based interceptors as impractical, but the panelists said the technology has significantly evolved since the 1990s and that the concept deserves stronger consideration.

In its budget request, the Obama administration asked for approximately $6.5 million for space activities, with much of that funding going toward operating experimental satellites such as the Space Tracking and Surveillance System.

Baker Spring, a research fellow at the Heritage Foundation, a think tank here, described the administration’s spending on the program as “a really, really pathetic thing in what should be a high priority.”

Jeff Kueter, president of the Marshall Institute, another think tank here, said technology has evolved and that the program should be pursued. “We’ve neglected it for way too long,” he said.

In 2012, a study from the National Research Council concluded that an effective space-based boost-phase interceptor program would require hundreds of satellites and cost at least 10 times as much as any other approach, potentially topping out at $500 billion.

Mike Gruss is a senior staff writer for SpaceNews. He joined the publication in January 2013 to cover military space. Previously, he worked as a reporter and columnist for The Virginian-Pilot in Norfolk, Va. and The Journal Gazette in Fort Wayne, Ind. He...