why do we have satellites in space
Without these things, our daily lives would look much different. Some of us couldn't watch. Some of us couldn't figure out how to
from one to another when traveling. Some of us could be by bad weather that we didn't know was coming. What are we talking about? Satellites, of course! Satellites are any objects that revolve around ( ) another in space. Some satellites are, while others are (man-made). The is an example of a satellite that orbits the Earth. We're going to, though, on the man-made satellites. satellites are machines that humans launch into, usually around the Earth. satellites can be sent to other planets, too. For example, there are currently satellites orbiting the, the Sun, and several other planets, including Mercury, Venus, Mars, and Saturn. The Soviet Union launched the first satellite в в on October 4, 1957. The United States launched its first satellite в в about four months later. Since that time, over 2,500 satellites have been launched into space. Would you have ever guessed there are that many satellites up there in the, traveling around the Earth over and over again? What in the world do they do up there? Why do we so many of them? satellites are used for all sorts of purposes. Satellites like the Hubble Space Telescope, the International Space Station, and the Russian Mir space station help scientists explore space in new and exciting ways. Communications satellites help us communicate with people all over the world. Weather satellites help us observe the Earth from space to help predict weather patterns. Radio and satellites beam our favorite songs, movies, and to Earth for us to. There's even a group of 27 satellites that make up the Positioning System ( ). Without these satellites, we couldn't use GPS devices to find our way while traveling. If you're wondering how that many satellites stay in without bumping into each other, just remember that space is veryвwellв!
Compared to our measurements on Earth, the size of space seems. Even though there's a lot of room in space, satellites are launched into orbits at different distances from Earth. Some may be as close as 150 miles above Earth, while others may be as far away as 20,000 miles or more. Most satellites within 500 miles of Earth or what scientists call low-Earth. These satellites have to travel very fast в about 17,000 miles per hour в to avoid being sucked back into Earth's atmosphere. Sooner or later, though, the force of will pull all objects, including satellites, back to Earth. When satellites quit working, they become orbiting вspace junk" until pulls them back to Earth. Although at least one piece of space junk returns to Earth every day, it's rare that anyone ever notices. So no to worry that the is! This is our annual update on the satellites currently orbiting the Earth. How many satellites are orbiting the Earth? According to the Index of Objects Launched into ), there are 4 635 satellites currently orbiting the planet; an increase of 8. 91% compared to last year. So far in 2017, UNOOSA has recorded 357 objects launched into space. This is almost 50% more than have ever previously occurred in a single year, and there are still a significant number planned during the rest of the year. This increase is fuelled by small satellites and cubesats. New technology has significantly reduced the cost to design, build and launch these, and this has been accompanied with an increase in commercial providers becoming involved in the market. A earlier this month by the Satellite Applications Catapult predicted that 1 300 of these satellites will be launched over the next three years.
If you consider that just under 7,900 objects have been launched into space, this would equate to 16. 5% of the total launches over the last 60 years! How many of these orbiting satellites are working? The keeps a record of the operational satellites and you may be surprised to know that only 37. 5% of the orbiting satellites are active, just 1 738 according to the August 2017 update. This means that there are 2 897 pieces of junk metal hurtling around the Earth at high speed! What are all these satellites doing? Although, it should be noted that some of the satellites have multiple purposes. Weвll examine the Earth observation category in more detail in a future blog. What is Technology Development/Demonstration? This is quite an intriguing purpose as it should give an idea of what is happening in the industry, and perhaps unsurprisingly the UCS data has little information on what these satellites are actually doing. However, some insights can be gained by looking at the operators of, and countries controlling, these satellites. 33 have military uses with 80% of these being the USA, the rest from China, Russia and France. 56 have government uses and most of these are operated by National Space Agencies, or associated bodies. China has 52% of these satellites, followed by USA. 65 have Civil uses and these are mostly run by Universityвs or similar educational establishments. 39 have Commercial uses. There are 33 different countries operating technology development/demonstration satellites with the USA leading the way having 63, followed by China with 41 and Japan with 19. After this it is mostly just one or two satellites for each country. Who uses the satellites? The four categories of users in the previous section can also be reviewed for all satellites, such that: Although, it should be noted that almost 14% of the satellites are listed as having multiple uses.
Which countries have launched/operate satellites? According to UNOOSA 70 countries have launched satellites, although this is slightly complicated by the fact that a number of satellites have also been launched by various institutions such as the European Space Agency. Looking at the UCS database, there are 66 countries listed as currently operating satellites, which means around 25% 33% of the worldвs countries have eyes in space (depending on how you define a country/territory! ) There is an interesting infographic on the showing the change in countries operating satellites between 1966 and 2016. In terms of countries with the most satellites, the USA significantly leads the way with 803 satellites, almost four times as many as China who is next with 204 and followed by Russia with 142. Interesting Facts! The oldest active satellite is the Amsat-Oscar 7 communications satellite which was launched 43 years ago today! (15th November 1974) Planet operates the largest number of satellites with their constellations accounting for 191 of current active satellites в although with Planet this could have gone up already! Second largest operator is Iridium Communications with 83 satellites. 61. 6% of operational satellites are in low-earth orbits (LEO), 30. 6% in geostationary orbits, 5. 6% in medium-earth orbits and 2. 2% in elliptical orbits. Of the LEO, 55. 4% are sun-synchronous, 25. 6% are non-polar inclined, 15. 6% are polar, 1. 9% are equatorial, 0. 8% are elliptical and 0. 1% are cislunar (and yes, we had to look that one up too! ) The remainder did not specify an orbit type. When you look up! Next time you gaze up into the sky looking at that stars, think about the 4,500 or so hunks of metal twinkling up there too!
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