A Japanese spy satellite launched in February 2007 to keep an eye on North Korea has shut down and prospects for reviving it are “extremely grim,” the Daily Yomiuiri and other Japanese media outlets reported over the weekend.

Japan’s Cabinet Satellite Intelligence Center said the nation’s lone radar-imaging satellite experienced a battery-related glitch Aug. 23 that took the spacecraft out of service.

Owing to a November 2003 launch failure that destroyed two spy satellites, Japan has just four spy satellites in orbit, including the balky radar craft.

      “Currently, there are three optical intelligence-gathering satellites, one of which has already passed its life expectancy, and one radar craft in orbit.

      “Since the only radar craft has stopped functioning, the government must wait until after fiscal 2012 before a complete set of reconnaissance satellites — two optical and two radar — are in operation.

      “The radar satellite is more expensive and technologically sophisticated than the optical orbiters. The radar No. 1 satellite, which was launched in 2003, stopped operating in 2007 because of a battery problem, one year short of its life expectancy.”