On 18 June 1962, a new era in astronomy started when a rocket experiment demonstrated the presence of X-ray radiation outside the solar system. Leading the project was Riccardo Giacconi, who later constructed Uhuru, the first X-ray satellite, and Einstein, the first space telescope with X-ray optics. In this way, Riccardo Giacconi has led the development of X-ray astronomy. This has increased our understanding of individual remarkable objects, as well as large-scale cosmic relationships.