The leaders of a Senate panel thanked the Defense Department on Friday for its response to their subpoena demanding documents linked to last month’s military base closing recommendations, saying it offers hope that the closure process will be transparent.

Sens. Susan Collins, R-Maine, and Joseph Lieberman, D-Conn., said the Committee on Homeland Security and Governmental Affairs has received thousands of pages of information from the Pentagon that met most of the targeted requests contained in the subpoena whose extended deadline passed at noon.

Collins, the committee chairwoman, and Lieberman, the ranking Democrat, represent states that were among the hardest-hit under the recommended closings. They say documents containing information used by defense officials in reaching those decisions are needed in order to counter them.

“Your assurances give us reason to hope that the process will in fact be accountable and open, and that DoD will embrace – not resist – attempts by communities and Congress to ensure that the right decisions have been reached,” the senators said in a letter to Acting Deputy Defense Secretary Gordon England.

Collins and Lieberman also expressed appreciation for England’s commitment to allow the committee to have access to Pentagon analysts who helped generate the documents being offered for review.

The committee issued its subpoena after members of Congress and state officials complained that the Pentagon was slow in releasing information and backup material that could be used to press their case at upcoming hearings on the proposed base closures.

Collins has challenged the department’s recommendation to close the Portsmouth Naval Shipyard in Kittery and a Defense Finance Accounting Service center in Limestone and remove all aircraft from Brunswick Naval Air Station. Lieberman is seeking to reverse the plan to close the Navy Submarine Base in New London, Conn.

Collins also advised community task forces working to preserve the three Maine bases that she was sharing with them the relevant information included in the documents provided by the Pentagon and on its Web page.

To overcome technical problems, Collins said her staff was working to create a searchable database of relevant documents and expects it to be operational by early next week.

The leader of the community-based campaign to save Brunswick Naval Air Station said his team expects to put in 10- and 12-hour days mining the data to bolster the case for retaining the surveillance aircraft now based there.

“It’s just a tremendous amount of reading,” said Rick Tetrev, a former Navy commander who maintains that the data will demonstrate the Navy failed to do a proper analysis before reaching its “foregone conclusion.”

Tetrev said the Brunswick task force will continue to go through the documents even after the July 6 BRAC hearing in Boston because whatever material it finds can be filed in writing with the commission into August.

Reversing a previous decision, the Base Realignment and Closure panel scheduled a visit by one commissioner to the northern Maine DFAS center on June 28.

The center, which provides more than 300 jobs, had been created as a way to soften the blow of the closing of Loring Air Force Base a decade ago.