outer space communication

Propagation of EM Waves in Atmosphere - In an Earth environment, electromagnetic waves propagate in ways that depend not only on their own properties but also on those of the environment itself. Since the various methods of propagation depend largely on frequency therefore the complete electromagne..

One desirable feature of radio transmission is that it should be carried without wires (i.e.,) radiated into space. At audio frequencies, radiation is not practicable because the efficiency of radiation is poor. However, efficient radiation of electrical energy is possible at high freque..

Communication satellites are normally geostationary satellites. They have devices called transponder which receive signals from an earth station and transmit them in different directions. The signals in the form of electromagnetic radiation are transmitted from the earth station and these..

Conclusion - Unfolding the mysteries of the dark and silent space with no known boundaries has always been a dream of the human race. The desires of man has ultimately been accomplished through the exploration of space using various space launching vehicles, space..

To place a satellite into orbit it needs to be accelerated in several stages. The required acceleration is produced by firing rockets at various stages of flight. These rockets are fitted into a system called 'launch vehicle' which carries the satellite. By firing rockets at appropriate heights, th..

Basic Principles of Wireless Radio Communication - Let us now discuss the basic principles of wireless radio communications. We shall mainly concentrate on the principle of amplitude modulation and demodulation. The simplest scheme of wireless communication would be to..

This type of wave propagation is said to be unguided. The uniform plane wave exists throughout all space. The electromagnetic energy associated with the wave spreads over a wide are..

The movement of ions is termed as flux. The movement of ions into the cell is called influx and the movement of ions from the cell to outside is known as efflux. Usually the uptake of mineral ions by the plant cells or tissues involve two main phases. In the first phase, tissues kept in mineral sol..

Movement of ions from the outer space of the cell to the inner space is generally against the concentration gradient and hence requires energy. This energy is obtained through metabolism either directly or indirectly. Various evidences indicate the active uptake of ion..

There are a small number of radioisotopes of low proton number, which occur naturally. They are produced by bombardment by radiation from outer space (cosmic rays). The most well known of these is radioactive carbon-14, which is produced when nitrogen is bombarded by neutron..