What is happening is that the satellite is actually orbiting the Earth at the same speed the Earth is rotating. The satellite makes a complete orbit around the Earth in 24 hours, or exactly one day. Longitude refers to those imaginary long lines that travel down the Earth for global mapping.
There are degrees of longitude readings for Earth. If you know the longitude of a satellite, you knows where the satellite is located in the sky because all geostationary satellites are located above the equator or zero latitude. To further confuse things, longitude is divided into two halves: western and eastern hemispheres. A satellite orbiting over Malaysia that services Asia and Australia may have the orbital slot of Satellite longitudes help installers locate where to point a satellite dish.
They also help in finding obstacles from an installation location and the satellite. Any obstacle such as a tree or mountain will interfere with a satellite signal. It is important that there are no obstacles between the installation location of the satellite dish and the orbiting satellite.
Fortunately, finding if there is clear line of sight is is simplified by using a look angle calculator. Plug these two details in, and the calculator will give you a compass heading of the satellite, and the degrees up from the horizon it is located, and a cool overhead picture of the installation location including a line showing the direction of the satellite.
Here is the free look angle calculator from Ground Control. Latency simply refers to how long it takes a single piece of information to make a round trip back and forth over a satellite connection. Data over satellite travels at the speed of light — , miles per second.
Who wants to pull a virtual trigger and wait half a second for the gun to go off? Ground Control iDirect services have a latency time between to milliseconds, which is only half as much as consumer-grade service providers. A common misconception is that latency has an effect on transfer rate, or the speed in which you can transfer a file.
This is not true. Even a screw or a bit of paint is considered an "artificial" satellite, even though these are missing these parts.
A satellite is best understood as a projectile, or an object that has only one force acting on it — gravity. Technically speaking, anything that crosses the Karman Line at an altitude of kilometers 62 miles is considered in space.
However, a satellite needs to be going fast — at least 8 km 5 miles a second — to stop from falling back down to Earth immediately. If a satellite is traveling fast enough, it will perpetually "fall" toward Earth, but the Earth's curvature means that the satellite will fall around our planet instead of crashing back on the surface. Satellites that travel closer to Earth are at risk of falling because the drag of atmospheric molecules will slow the satellites down.
Those that orbit farther away from Earth have fewer molecules to contend with. There are several accepted "zones" of orbits around the Earth. One is called low-Earth-orbit , which extends from about to 2, km about to 1, miles. This is the zone where the ISS orbits and where the space shuttle used to do its work. In fact, all human missions except for the Apollo flights to the moon took place in this zone.
Most satellites also work in this zone. Geostationary or geosynchronous orbit is the best spot for communications satellites to use, however. This is a zone above Earth's equator at an altitude of 35, km 22, mi. At this altitude, the rate of "fall" around the Earth is about the same as Earth's rotation, which allows the satellite to stay above the same spot on Earth almost constantly. The satellite thus keeps a perpetual connection with a fixed antenna on the ground, allowing for reliable communications.
When geostationary satellites reach the end of their life, protocol dictates they're moved out of the way for a new satellite to take their place.
That's because there is only so much room, or so many "slots" in that orbit, to allow the satellites to operate without interference. While some satellites are best used around the equator, others are better suited to more polar orbits — those that circle the Earth from pole to pole so that their coverage zones include the north and south poles.
Examples of polar-orbiting satellites include weather satellites and reconnaissance satellites. There are an estimated half-million artificial objects in Earth orbit today , ranging in size from paint flecks up to full-fledged satellites — each traveling at speeds of thousands of miles an hour.
Only a fraction of these satellites are useable, meaning that there is a lot of "space junk" floating around out there.
With everything that is lobbed into orbit, the chance of a collision increases. Space agencies have to consider orbital trajectories carefully when launching something into space.
Agencies such as the United States Space Surveillance Network keep an eye on orbital debris from the ground, and alert NASA and other entities if an errant piece is in danger of hitting something vital. This means that from time to time, the ISS needs to perform evasive maneuvers to get out of the way.
Collisions still occur, however. One of the biggest culprits of space debris was the leftovers of a anti-satellite test performed by the Chinese, which generated debris that destroyed a Russian satellite in Also that year, the Iridium 33 and Cosmos satellites smashed into each other, generating a cloud of debris.
NASA, the European Space Agency and many other entities are considering measures to reduce the amount of orbital debris. Some suggest bringing down dead satellites in some way , perhaps using a net or air bursts to disturb the debris from its orbit and bring it closer to Earth. Others are thinking about refueling dead satellites for reuse, a technology that has been demonstrated robotically on the ISS. The path a satellite follows is an orbit , which sometimes takes the shape of a circle.
To understand why satellites move this way, we must revisit our friend Newton. Newton proposed that a force -- gravity -- exists between any two objects in the universe.
If it weren't for this force, a satellite in motion near a planet would continue in motion at the same speed and in the same direction -- a straight line. This straight-line inertial path of a satellite, however, is balanced by a strong gravitational attraction directed toward the center of the planet. Sometimes, a satellite's orbit looks like an ellipse, a squashed circle that moves around two points known as foci. The same basic laws of motion apply, except that the planet is located at one of the foci.
As a result, the net force applied to the satellite isn't uniform all the way around the orbit, and the speed of the satellite changes constantly. It moves fastest when it's closest to the planet -- a point known as perigee -- and slowest when it's farthest from the planet -- a point known as apogee.
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