Planet-A mission to Halley

Looking at the chance of the next apparition of the Halley comet in 1986, ISAS decided to send a first Japasanese interplanetary spacecraft for the study of cometary hydrogen coma and solar wind. The Planet-A spacecraft which carries VUV imaging camera and solar wind plasma analyser will be launched in August 1985 and flyby the Halley comet in early March 1986 with the distance of several million kilometers from the comet nucleus. This mission is not only self-consistent but collaborative with other space mission as well as earth-bound observations. In the present paper, the Planet-A mission to Halley is described with brief explanation of the spacecraft.