X-ray astronomy was born in June 1962 with a totally unexpected discovery of a bright X-ray source (presently known as Sco X-1) in a historic rocket flight conducted by Riccardo Giacconi, Herb Gursky, Frank Paolini and late Bruno Rossi. In the last 30 years, astronomy through the newly opened window has made a dramatic expansion.

The universe contains enormously rich varieties which had been left unexplored until recent times. From 40’s through 60’s, new wavelength windows, radio, infrared and X-rays successively opened. As a result, the presence of objects and regions distributed over an extremely wide temperature range from a few Kelvin through hundreds of millions of Kelvin were discovered. A burst of surprising discoveries made in 60’s marked the opening of a whole new era of multi-wavelength astronomy.