The government is thinking of earmarking research funds in the fiscal 2010 budget to develop a satellite that can detect missile launches, sources said.

The project comes in the wake of North Korea's April 5 launch of a rocket over Japan that Tokyo, Washington and Seoul believe was a long-range ballistic missile test. The rocket flew over the Tohoku region.

Tokyo relied on a U.S. satellite to obtain information about the launch. Some government insiders think the time is ripe for Japan to seriously assess the feasibility of maintaining a satellite system of its own, despite the huge costs it may entail, the sources said.