first Japanese scientific satellite, launched on Sept. 28, 1971. Shinsei observed solar radio emissions, cosmic rays (cosmic ray), and plasmas (plasma) in Earth's ionosphere (ionosphere and magnetosphere). The 66-kg (145-pound) satellite was launched under the auspices of the Institute of Space and Astronautical Science, which was then part of the University of Tokyo. The launch vehicle was a solid-fueled M-4S rocket. Shinsei is the Japanese word for “new star.” The satellite ceased operations in 1973, but it still remained in orbit.