Japan plans to develop a new model of its M-5 solid-fuel rocket by 2007, officials of the Institute of Space and Aeronautical Science said Thursday.

The new rocket will be an improved version of the current M-5 but will cost about half as much per launch, they said.

The M-5 rocket, developed by ISAS, is about 30 meters long and weighs some 140 tons. It is designed to put satellites of up to 1.8 tons into an orbit of 250 km.