Mu-3S-II | Yohkoh

The objective of Solar A or Yohkoh (Japanese for sunbeam) is to study the high-energy radiations from solar flares (hard and soft X-rays and energetic neutrons) as well as quiet structures and pre-flare conditions. The mission is a successor to Hinotori, a previous Japanese spacecraft flown at the previous solar activity maximum in 1981.

The Mu, also known as M, was a series of Japanese solid-fuelled carrier rockets, which were launched from Uchinoura between 1966 and 2006. Originally developed by Japan's Institute of Space and Astronautical Science, Mu rockets were later operated by Japan Aerospace Exploration Agency following ISAS becoming part of it.

ISAS is a Japanese national research organization of astrophysics using rockets, astronomical satellites and interplanetary probes which played a major role in Japan's space development.