Introduction
In the second century AD a Greek writer named Lucian wrote a story about a trip to the moon. He did not even know how far the moon was but his story revealed that the idea of space travel was certainly not new.
Space Launching Vehicles
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.
Race to the Moon
As soon as rockets could break away from the earth's gravity, moon became the next goal. Russians took the lead landing their spacecraft LUNA-3 which photographed the far side of moon in 1959. Meanwhile, the United States launched 11 unmanned moon missions without a single one completing its objective. Then the Apollo programme began and on July 21, 1969, Apollo-11 landed the first astronauts on the moon.
Parameters that Define the Orbit of a Satellite
Expertise is required in the planning, designing and fabrication of satellites. Each satellite has to be designed according to the purpose for which it is used. Also, one should have the basic infrastructure to fabricate the parts of the satellite with high degree of precision and to assemble the satellite.
Different Types of Artificial Satellites and their Orbits
Low earth orbit lies in the equatorial plane just lying above the atmosphere a few hundred miles up.
Communication Satellites
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 signals are received by the satellite.
Weather Satellites
Scientists who investigate weather phenomenon are called meteorologists. To study a particular feature, may require an observation from a larger area. By combining great number of observations and analysing them by computers it is possible to get information about a large weather system.
Remote Sensing
The cameras used on Landsat satellites are extremely complex. They use a process called remote sensing, in which the cameras scan the earth to look for different patterns of radiation.
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 probes and satellites.
