Japan's only working radar satellite has malfunctioned and officials say they may not be able to save it.

The intelligence-gathering satellite aimed at North Korea and China started acting up Monday, The Yomiuri Shimbun said Sunday.

Officials at Japan's Cabinet Satellite Intelligence Center said the likelihood of the orbiter being saved is "extremely grim." A replacement satellite can't be launched until 2011.

Its loss will hamper Japan's intelligence-gathering activities over North Korea and China at a time when both countries are expanding military capabilities, the report said.

Japan has three optical intelligence-gathering satellites, one of which has already passed its life expectancy; its other radar satellite quit working in 2007.

Officials said the radar satellite's batteries could be causing the problem. It was launched in 2007 and should have operated until 2012, the report said.

Japan plans to launch four intelligence-gathering satellites in fiscal year 2012, two for photo-reconnaissance, and two cloud-penetrating radar satellites.