Japan's first Ionosphere sounding satellite was named Ume. It was used to monitor radio waves in the ionosphere and forecast conditions for optimal use of shortwave communications.
Ume-2 was put into orbit two years later - a power supply system failure caused Ume to malfunction one month after launching.
Ume-2 kept gathering obserration data even after its 1.5 year mission term. And it finished its operation on February 23,1983,because of deterioration of power generation.