The first site for a U.S. Air Force next-generation space surveillance radar network will be located on Kwajalein Atoll in the Marshall Islands, a senior service official said.

The Air Force plans to award a contract for Space Fence in spring 2013 but the service may not provide funding for building a second site anytime soon because of shrinking budgets, Gen. William Shelton, commander of Air Force Space Command, said Sept. 18 during a media roundtable at a defense conference in National Harbor, Md. The full system will be a two-site system, he said. The first site will feature a larger radar than the second site, Shelton said.

Initial operational capability for the first Space Fence site is scheduled for fiscal year 2017, Shelton said.

The long-delayed radar system is expected to track a far greater number of low Earth orbiting objects than the current VHF-band Space Fence, a line of radars deployed across the southern United States during the 1960s. The new S-band system is expected to cost about $3.5 billion.

A final Air Force request for proposals to build the new Space Fence is due out this fall. Lockheed Martin Mission Systems & Sensors of Washington, and Raytheon Integrated Defense Systems of Tewksbury, Mass., each won $107 million contracts in January 2011 for design work on the Space Fence that concluded over the summer. Both companies built prototypes that successfully tracked objects in space.