This coin commemorates the first launch of the Zenit-3SL carrier rocket from the Ocean Odyssey platform, which took place on 28 March 1999 and marked an important stage in the history of domestic and international rocket engineering. The rocket, which was developed by the Pivdenne Design Office and produced by the Pivdenmash Plant, successfully demonstrated the launch capabilities of Sea Launch, a multinational spacecraft launch service. The Sea Launch Project was one of the most interesting and revolutionary international space projects introduced in the late 20th century. It used a mobile maritime launch platform for equatorial launches for the first time. The platform took full advantages of the Earth’s rotational effect, launching into orbit increased payloads, while reducing fuel consumption. The environmental friendliness of the Zenit-3SL carrier rocket is of great importance today, and makes it unique.