Operation and experimental results of Ionosphere Sounding Satellite-b (ISS-b, UME-2). I - Outline of ISS-b project

Design and operational features of the Japanese Ionosphere Sounding Satellite (ISS-b) are described. The ISS-b, second in a series and replacing ISS-a, which failed after a month in orbit, was launched on an N-type rocket in February 1978. Its 1100 km circular orbit inclines at a 70 deg angle and has a 107 min period. The spacecraft carries a digital swept frequency sounder for ionospheric topside measurements, narrow band HF receivers for noise measurement, a retarding potential trap for plasma measurement, and ion-mass spectrometers for analyzing positive ion composition. Instrument readings are recorded sequentially on tape every 64 sec.