První družice světa, první živý tvor ve vesmíru, první sondy k Měsíci, první člověk na oběžné dráze... Sovětský svaz sbíral v počátcích kosmické éry lidstva prvenství jako na běžícím pásu. Spojené státy nástup věku kosmických letů podcenily a najednou nemohly chytit dech. and Tomáš Přibyl.
Padesát let po svém založení dnes National Aeronautics and Space Administration (NASA) s dlouhou řadou výzkumníků táhnoucí se celou její historií vede ve výzkumu vesmíru celý svět. Její kosmonauté obletěli Zemi, prošli se po Měsíci, pilotovali první okřídlené vesmírné plavidlo a zkonstruovali Mezinárodní vesmírnou stanici (ISS)., Z podkladů NASA zpracovala Andrea Cejnarová., and Obsahuje blahopřání G. W. Bushe
The launching of man-made satellites required some new urgent scientific and technical investigations. One of them was the establishment of a simple method of determining the path of a ray, adapted for fixing the optimum condition at which a radio connection between any two points of the Universe can be realized.
Recently the solution of three important radio-communication problems has been put on the list of urgent requirements:
1. The radio communication between any two points of the Earth surface at any time, season or solar activity.
2. The radio communication between any point of the Earth surface and any point of the Universe.
3. The connection between visitors of a smáli planet with a rare atmosphere, especially if one of them has disappeared below the horizon, up to the antipodal point. The theory of radio propagation, elaborated in Chapter 3, shows that the trajectory of a wave which is passing through a spherical ionized layer can generally be found
by merely knowing the critical frequency ~ of the layer and the whole
quantity of electrons present in the layer. (We need not to know the distribution of electrondensity diV/dr with height as it has been supposed previously.) Consequently, in order to gain the best information about a rádio trajectory it is necesary to know the critical frequency of the F2-layer anywhere on the Earth at any time season and solar activity (Chapter 1), to be able to predict the sunspot number (Chapter 2), to elaborate a simple but precise theory of radio propagation (Chapter 3). Taking into account the results of these three chapters we were able to elaborate a very practical method which made it possible to determine the best conditions for
any terrestrial or astronautical connection. (Chapter 4.) The main idea of the first two chapters will be mentioned only briefly but the
chapter 3 and 4 will be reproduced in greater detail. References to the equations or figures of the Russian text are indicated by three
numbers: the chapter, the section and the equation, figure or advise on literature.