Sushi
Sasei (No. 10 Scientific Satellite, PLANET-A) is the second space exploration aircraft launched by Japan Institute of Space and Astronautical Science (currently the Japan Aerospace Exploration Agency). It was launched from the Kagoshima Space Observatory on M - 3 SI I rocket No.2 on August 19, 1985. Sushi participates in Halley's International Cooperation Exploration Plan (known as the Halley Fleet) along with the predecessor ahead of time that has been launched earlier, observes the interaction between the solar wind and the atmosphere of Halley's comet, and images the comet's frame with ultraviolet light It was aimed at. On November 14, 1985, SUISEI photographed the image of Halley's comet's hydrogen Ly α bright line for the first time using a vacuum ultraviolet imaging device. From observation of this image, it became clear that the brightness of the frame was regularly changing, and the rotation cycle of the nucleus was changed from 2.2 ± 0.