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Satellite | A satellite is any object that orbits another object (which is known as its primary). All masses that are part of the solar system, including the Earth, are satellites either of the Sun, or satellites of those objects, such as the Moon.
It is not always a simple matter to decide which is the 'satellite' in a pair of bodies. Because all objects exert gravity, the motion of the primary object is also affected by the satellite. If two objects are sufficiently similar in mass, they are generally referred to as a binary system rather than a primary object and satellite; an extreme example is the 'double asteroid' 90 Antiope. The general criterion for an object to be a satellite is that the center of mass of the two objects is inside the primary object. read more ...
| Satellite television | Satellite television is television delivered by way of communications satellites, as compared to conventional terrestrial television and cable television. In many areas of the world satellite television services supplement older terrestrial signals, providing a wider range of channels and services, including subscription-only services. read more ...
| Satellite radio | A satellite radio or subscription radio (SR) is a digital radio that receives signals broadcast by communications satellite, which covers a much wider geographical range than normal radio signals.
SR functions anywhere where there is line of sight between the antenna and the satellite, given there are no major obstructions, such as tunnels or buildings. SR audiences can follow a single channel regardless of location within a given range.
Because the technology requires access to a commercial satellite for signal propagation, SR services are commercial business entities (not private parties), which offer a package of channels as part of their service —requiring a subscription from end users to access its channels. Currently, the main SR providers are WorldSpace (Intl.), XM Radio & Sirius (U.S.), as part of their each being proprietary and non-compatible signals, requiring proprietary hardware for decoding and playback. Both these and other services have news, weather, sports, and several music channels. read more ...
| Petite Amateur Navy Satellite FAQ | What type of facilities are located at NPS? Were the facilities established specifically for the PANSAT project?
An infrastructure of tools and facilities has been compiled to promote the successful completion of the PANSAT project. Machining capabilities are held within the Space Systems Academic Group in the form of a CNC vertical mill, providing short lead times for one-of-a-kind parts. Facilities are also in place for component and subsystem environmental testing. The major testing facilities currently operable include a 500 pound shaker and a 1 cu. ft. thermal-vacuum chamber. We also have an assortment of software tools for mechanical design and test, electronic design, thermal analysis and orbital mechanics. These tools were acquired for use in the academic courses, instructional labs, and on the PANSAT project as well as other SSAG projects such as the Space ThermoAcoustic Refrigerator (STAR). read more ...
| What is an LNB? | Low Noise Block-downconvertor (so called because it converts a whole band or "block" of frequencies to a lower band).
An LNB sits on the end of an arm and faces the parabolic reflector ("dish") which focusses the signals from a satellite 24,000 miles away into the "feed horn" of the LNB.
The LNB converts the signals to a lower frequency and sends them out to the cable connector, which you connect to your satellite receiver via coaxial cable. read more ...
| What Is a Satellite? | A satellite is something that goes around and around a larger something, like the earth or another planet. Some satellites are natural, like the moon, which is a natural satellite of the earth. Other satellites are made by scientists and technologists to go around the earth and do certain jobs. read more ...
| What is an orbit? | When a satellite is launched, it is placed in orbit around the earth. The earth's gravity holds the satellite in a certain path as it goes around the earth, and that path is called an "orbit." There are several kinds of orbits. Here are three of them. read more ...
| How Does a Satellite Get Into Space? | A satellite is launched on a launch vehicle, which is like a taxicab for satellites. The satellite is packed carefully into the vehicle and carried into space, powered by a rocket engine.
Satellites are launched from only a few places in the world, primarily Cape Canaveral, Florida; Kourou, French Guiana; Xichang, China, and Baikonur, Kazakstan. The best places to launch satellites are near the ocean, so that when the launch vehicle falls away, it lands in the water and not on people.
Another launch site actually travels to the perfect launch spot. The Sea Launch company rebuilt a big platform once used for oil drilling at sea. The platform carries satellites from Long Beach, California, to the equator, far out in the Pacific Ocean, where its rocket launches them. read more ...
| When a Spaceship Lands on the Moon, Why Doesn't It Fall Off? | The earth, the moon, and all the planets are held in place in the solar system by two opposing forces. One is called gravity. Gravity is a force that pulls objects toward a planet or other large object. When you hold a book in the air and let go, gravity pulls it toward the earth and it falls. read more ...
| What Does a Satellite Do? | Satellites do many things for people. Their most important job is helping people communicate with other people, wherever they are in the world:
A satellite can carry a camera as it travels in its orbit and take pictures of the whole earth
Satellites in orbit can send messages to a special receiver
A satellite can relay your telephone call across the country
A satellite can transmit your favorite TV program read more ...
| How Big Is a Satellite? | Different kinds of satellites are used in different situations, for different purposes. To talk about the sizes of satellites, we'll use two examples: the Boeing 601, which is used mostly for direct broadcast TV and business communication networks, and the Boeing 702, which is used mostly for video distribution, satellite telephone and Internet services, and digital radio. read more ...
| Who Owns the Satellites? | Satellites are usually owned by companies or countries. The companies that own satellites usually want to make money by renting out part of the satellite to other companies. The countries or government agencies that own satellites want to make people's lives better by improving the communication networks in their countries. read more ...
| Satellite phones | A satellite phone or satphone is a mobile phone that communicates directly with orbiting satellites. Depending on the architecture of a particular system, coverage may include the entire planet, or only specific regions.
Satellite phone (Inmarsat)
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Satellite phone (Inmarsat)
The mobile equipment, also known as a terminal or earth station, varies widely. A satellite phone handset has a size and weight comparable to that of a late 1980s or early 1990s cell phone, but with a large retractable antenna. These are popular on expeditions into remote areas where terrestrial cellular service is unavailable.
A fixed installation, such as used shipboard, may include large, rugged, rack-mounted electronics, and a steerable microwave antenna on the mast that automatically tracks the overhead satellites. read more ...
| Satellite Internet | Satellite internet services are used in locations where terrestrial Internet access is not available and in locations which move frequently. Internet access via satellite is available globally, including vessels at sea. There are three types of satellite Internet service:
one-way multicast,
one-way with terrestrial return, and
two-way satellite access. read more ...
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