Moon constellation of 4 13 _ 4. Moon constellation of13

Question 1: How many satellites are there on the earth? At present, there are 338 geosynchronous satellites in use, of which 35 are hovering over South Korea and its vicinity. Among these 35 synchronous satellites, there are 3 from South Korea, 0/4 from China and 0/8 from Japan. "

According to the information I have found, the number of satellites in geosynchronous orbit should be large in theory: because they are all celestial bodies at rest relative to the earth, about 36 thousand kilometers above the equator of the earth, it is conceivable how many satellites can be accommodated there. Theoretically, its number is quite large, but due to technology and some inevitable factors, the satellite can not be absolutely stationary relative to the earth, and it will also deviate from the geosynchronous orbit. In order to prevent accidents caused by satellite crowding (specifically, it may be collisions, because they are not absolutely stationary and may seriously deviate from the original orbit in some cases), the actual number will be greatly reduced. However, its number is still quite large, and it is still enough for human use at this stage.

However, due to the intention of some countries, they occupy the geostationary satellite orbit space of other countries (because their countries are relatively small and the available orbit space is very small), so some countries now have a tendency to compete for the geostationary satellite orbit space.

Question 2: How many natural satellites are there on the earth? The earth has three natural satellites, one is the moon, and the other two are two nebulae, which rotate around the earth in an equilateral triangle with the moon! Because they are nebulae, the reflected light is so small that we can't see them, so we think there is only one moon! !

Question 3: How many satellites are there on the earth? There is only one satellite on earth, and that is the moon.

But satellites, there is no way to calculate.

Question 4: How many satellites are there on the earth? According to the usual logic, it is generally believed that the satellite of the earth is the moon, but this answer is obviously not comprehensive enough. 1On October 4th, the former Soviet Union sent the world's first artificial earth satellite into space by satellite launch vehicle. Although the structure of the satellite at that time was relatively simple, it was the first artificial celestial body in the world. After the emergence of artificial earth satellites, the former Soviet Union and the United States in the 1960s. In the 1970s, military and civilian satellites entered the application stage in an all-round way, and developed in the direction of specialization such as reconnaissance, communication, navigation, early warning, meteorology, geodesy, ocean and earth resources. At the same time, all kinds of satellites are developing towards multi-purpose, long life, high reliability and low cost. In the late 1980s, the new single-function miniaturized satellite was the new trend of satellite development. This small satellite with light weight, low cost, short development cycle and quick effect will be a new force in the future satellites. Apart from the United States and the Soviet Union, China, the European Space Agency, Japan, India, Canada, Brazil, Indonesia, Pakistan and other countries have their own satellites. According to the latest global satellite database recently released by an American organization called "Union of Concerned Scientists", there are currently 795 satellites of all kinds orbiting the earth, more than half of which belong to the United States, the only superpower in the world. Its number of satellites has exceeded the sum of all other countries, reaching 4 13, and the number of military satellites has reached more than a quarter.

Question 5: How many satellites are there in the world? Up to now, countries around the world have launched more than 5,000 satellites of various types (the United States and Russia account for the vast majority), of which military satellites account for about 70%.

Types and applications of artificial earth satellites;

Composition of artificial earth satellite

Satellites generally consist of two parts, namely, the payload platform. Payload refers to the instruments and equipment used on the satellite to directly realize the satellite's self-use purposes or scientific research tasks, such as cameras used on remote sensing satellites, communication transponders used on communication satellites, communication antennas, etc. Platform is all supporting systems that serve the payload to ensure its normal operation, generally including structural system, temperature control system, power supply system, radio measurement and control system, attitude control system and orbit control system.

Flight principle of artificial earth satellite

The artificial earth satellite can run in the earth orbit, firstly because it has the first cosmic speed (7.9 km/s), and secondly because the gravity (centripetal force) of the earth keeps pulling it, just like pulling a stone on a thin rope. If the satellite flies fast and the centrifugal force exceeds the gravity of the earth, it will leave the earth and fly to distant space.

The five earliest stars hanging in heaven

The first man-made satellite was made in the former Soviet Union. The second type uses the Japanese satellite Otsuka, the third American Explorer 1, the fourth French experimental satellite No.1 and the fifth China Dongfanghong No.1..

I. Scientific exploration satellites

Scientific exploration satellite is a satellite used to detect the physical environment in space. Its main task is to detect neutral particles, high-energy charged particles, solid particles, low-frequency electromagnetic waves and plasma waves, magnetic fields and electric fields in the space environment.

Two. Satellite application

Application satellite is an artificial earth satellite that directly serves the national economy and military affairs. According to the purpose, it can be divided into communication, meteorology, reconnaissance, navigation, geodesy, earth resources and multi-purpose satellites.

1. communication satellite

Classification of communication satellites

There are many kinds of communication satellites, which are divided into geostationary orbit communication satellites and flying geostationary orbit communication satellites according to their orbits. According to the purpose, there are broadcast and television direct broadcast satellites, tracking and data interruption satellites, maritime satellites and military communication satellites.

The use of artificial satellites

With the appearance of artificial satellites, especially since the third geosynchronous satellite realized global communication, we can enjoy wonderful live broadcast at home.

Navigation global positioning system

"Global Positioning System", also known as "navigation", is a constellation composed of 24 satellites, which can accurately locate any place on the earth. Users can use a very small receiver to receive signals from four GPS satellites and calculate position data. The accuracy of military horizontal distance and height is 5 meters, and the civilian average is 15 meters.

Global navigation satellite system

The military global satellite navigation system and positioning system developed by the Soviet Union/Russia have the same function as the navigation satellite global positioning system of the United States.

satellite navigation system

At 0: 34 on May 25, 2003, China successfully sent the third Beidou-1 navigation and positioning satellite into space by the Long March III in xichang satellite launch center, which indicated that China has independently established a perfect navigation system and will play an active role in China's national economic construction.

This launch is the third Beidou-1 navigation and positioning satellite. The first two Beidou-1 satellites were launched on June 3rd and February 2nd, 2000, respectively. The navigation and positioning system is not working yet. This launch is a backup star of the navigation and positioning system. Together with the first two Beidou-1 satellites, it forms a complete satellite navigation and positioning system to ensure that satellite navigation information is provided all day.

2. Meteorological satellites

Meteorological satellites can be divided into sun-synchronous orbit meteorological satellites and geostationary orbit meteorological satellites. Sun-synchronous orbit meteorological satellites patrol the earth's surface twice a day. Global meteorological data can be obtained. Geostationary meteorological satellites can continuously observe the global 1/3 area and send meteorological data back to the ground in real time.

3. Resource satellites

Resource satellites are satellites that survey and study the earth's resources. It can see through the stratum, find underground treasures, historical sites and stratum structure that people can't see with the naked eye, and can survey crops, forests, oceans, air and other resources. It can predict and identify the harvest of crops, and check and predict various natural disasters.

4. Returning remote sensing satellite

The recoverable satellite is a low-orbit satellite, which has three main purposes: observing the earth for a period of time and obtaining remote sensing information; The second is to conduct microgravity experiments; The third is the technical reserve for manned flight return.

5. reconnaissance satellite

Reconnaissance satellite is an artificial earth satellite, which is used to collect and intercept military intelligence. The advantages of satellite reconnaissance are as follows:>