IN SPACE EXPLORATION

 SPACE EXPLORATION -;

Space exploration, the investigation, by means of crewed and uncrewed spacecraft, of the reaches of the universe beyond Earth’s atmosphere and the use of the information so gained to increase knowledge of the cosmos and benefit humanity. A complete list of all crewed spaceflights, with details on each mission’s accomplishments and crew, is available in the section chronology of crewed spaceflights .

 Humans have always looked at the heavens and wondered about the nature of the objects seen in the night sky. With the development of rockets and the advances in electronics and other technologies in the 20th century, it became possible to send machines and animals and then people above Earth’s atmosphere into outer space. Well before technology made these achievements possible, however, space exploration had already captured the minds of many people, not only aircraft pilots and scientists but also writers and artists. The strong hold that space travel has always had on the imagination may well explain why professional astronauts and laypeople alike consent at their great peril, in the words of Tom Wolfe in The Right Stuff (1979), to sit “on top of an enormous Roman candle, such as a Redstone, Atlas, Titan or Saturn rocket, and wait for someone to light the fuse.” It perhaps also explains why space exploration has been a common and enduring theme in literature and art. As centuries of speculative fiction in books and more recently in films make clear, “one small step for [a] man, one giant leap for mankind” was taken by the human spirit many times and in many ways before Neil Armstrong stamped humankind’s first footprint on the Moon.

1- SATELLITE LAUNCHING -;

Satellites stay in space for most of their life time. We know that the environment of weightlessness is present in the space. That’s why satellites don’t require additional strong frames in space. But, those are required during launching process. Because in that process satellite shakes violently, till the satellite has been placed in a proper orbit.

The design of satellites should be compatible with one or more launch vehicles in order to place the satellite in an orbit.

We know that the period of revolution will be more for higher apogee altitude according to Kepler’s second law. The period of geostationary transfer orbit is nearly equal to 16 hours. If perigee is increased to GEO altitude (around 36,000 km), then the period of revolution will increase to 24 hours.

The process of placing the satellite in a proper orbit is known as launching process. During this process, from earth stations we can control the operation of satellite. Mainly, there are four stages in launching a satellite.

2- REMOTE SENSING  -;

Remote sensing is the acquisition of information about an object or phenomenon without making physical contact with the object and thus in contrast to on-site observation, especially the Earth. Remote sensing is used in numerous fields, including geography, land surveying and most Earth science disciplines (for example, hydrology, ecology, meteorology, oceanography, glaciology, geology); it also has military, intelligence, commercial, economic, planning, and humanitarian applications.

In current usage, the term "remote sensing" generally refers to the use of satellite or aircraft-based sensor technologies to detect and classify objects on Earth. It includes the surface and the atmosphere and ocean, based on  propagate signals (e.g. electromagnetic radiation). It may be split into "active" remote sensing (when a signal is emitted by a satellite or aircraft to the object and its reflection detected by the sensor) and "passive" remote sensing (when the reflection of sunlight is detected by the sensor).