We believe that the examination of the ultraviolet solar spectrum is the most informative tool for the diagnostic of the physical state of the solar plasma. But the well known phenomenon of fine structure of active regions (A.R.), as well as of quiet ones, making spectral lines to be wavy and patchy (across dispersion) demandsa) high spatial resolution on the solar image and b) stigmatic spectra.

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The twentieth century was one of rampant technological development, of unprecedented flourishing of science, a century in which grandiose, fantastic ideas became reality, and when the dreams of many generations of people who lived and now live on Earth came true. There were a great many ideas, discoveries, projects, and accomplishments in the century just past. But among all the numerous outstanding human achievements in the twentieth century that captured the contemporary imagination, the most thrilling were the launch of the first artificial satellite and, especially, the flight of the planet's first cosmonaut, Yuriy Alekseyevich Gagarin on the Vostok spacecraft. The launch of the first artificial satellite into orbit around Earth took place on 4 October 1957 at 22:28 Moscow time marking the start of the Space Era in human history. Yuriy Gagarin's spaceflight, launched on 12 April 1961 at 09:07 Moscow time, lasted for 108 minutes, during which the spacecraft carrying the first cosmonaut completed a full orbit around Earth and then landed safely in the scheduled recovery area. This flight marked the start of the Era of Human Presence in Space. These two events are directly linked; without the first, the second could never have occurred. The first became a momentous milestone in the history of technological progress; the second was the embodiment of a centuries‐old dream of humankind. This article details the preparations for the first flight and how Yu. A. Gagarin was chosen for the mission, Biographical information on Gagarin is given.

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