Why Are Satellites Important?

Satellites come in many shapes and sizes. But most have at least two parts in common - an antenna and a power source. The antenna sends and receives information, often to and from Earth. The power source can be a solar panel or battery. Solar panels make power by turning sunlight into electricity.

Many NASA satellites carry cameras and scientific sensors. Sometimes these instruments point toward Earth to gather information about its land, air and water. Other times they face toward space to collect data from the solar system and universe.

satellites are launched into space on rockets. A satellite orbits Earth when its speed is balanced by the pull of Earth's gravity. Without this balance, the satellite would fly in a straight line off into space or fall back to Earth.

Satellites orbit Earth at different heights, different speeds and along different paths. The two most common types of orbit are "geostationary" (jee-oh-STAY-shun-air-ee) and "polar.

A geostationary satellite travels from west to east over the equator. It moves in the same direction and at the same rate Earth is spinning. From Earth, a geostationary satellite looks like it is standing still since it is always above the same location.

Polar-orbiting satellites travel in a north-south direction from pole to pole. As Earth spins underneath, these satellites can scan the entire globe, one strip at a time.

Actually, they can. NASA and other U.S. and international organizations keep track of satellites in space. Collisions are rare because when a satellite is launched, it is placed into an orbit designed to avoid other satellites. But orbits can change over time. And the chances of a crash increase as more and more satellites are launched into space.

In February 2009, two communications satellites - one American and one Russian - collided in space. This, however, is believed to be the first time two man-made satellites have collided accidentally.

NASA has launched dozens of satellites into space, starting with the Explorer 1 satellite in 1958. Explorer 1 was America's first man-made satellite. The main instrument aboard was a sensor that measured high-energy particles in space called cosmic rays.

The first satellite picture of Earth came from NASA's Explorer 6 in 1959. TIROS-1 followed in 1960 with the first TV picture of Earth from space. These pictures did not show much detail. But they did show the potential satellites had to change how people view Earth and space.

Satellites looking toward Earth provide information about clouds, oceans, land and ice. They also measure gases in the atmosphere, such as ozone and carbon dioxide, and the amount of energy that Earth absorbs and emits. And satellites monitor wildfires, volcanoes and their smoke.

Satellites looking toward Earth provide information about clouds, oceans, land and ice. They also measure gases in the atmosphere, such as ozone and carbon dioxide, and the amount of energy that Earth absorbs and emits. And satellites monitor wildfires, volcanoes and their smoke.

All this information helps scientists predict weather and climate. The information also helps public health officials track disease and famine; it helps farmers know what crops to plant; and it helps emergency workers respond to natural disasters.

Satellites that face toward space have a variety of jobs. Some watch for dangerous rays coming from the sun. Others explore asteroids and comets, the history of stars, and the origin of planets. Some satellites fly near or orbit other planets. These spacecraft may look for evidence of water on Mars or capture close-up pictures of Saturn's rings.

Communication satellites beam television programs, radio messages, telephone conversations, and other kinds of information all over the world.

Navigation satellites send precise, continuous signals to ships and planes. (This helps pilots and sailors in determining their exact location )

Scientific satellites there are many types of this satellite. Some are used to prepare detailed maps, especially in remote areas. And also can map large areas with detailed rivers and mountain ranges.

The satellites are launched into the space to do a specific job, There are satellites that are launched to monitor the cloud patterns for the weather station, There are satellites that launched to send television signals for Sky TV, and every satellite has to be designed specifically to fulfill its function.

The satellites are used for many things such as the communication, the oceanography, the astronomy, the surveillance, They help many scientists get a perceptive view at all kinds of objects anywhere in the world.

The satellites send television signals directly to homes, They send the signals from a central station that generates programming to smaller stations that send the signals locally via the cables or the airwaves, The  news broadcasts are  sent from the field to the studio via the satellite.

The satellites provide in the flight phone communications on the airplanes, They are the main conduit of voice communication for the rural areas and the areas where the phone lines are damaged after a disaster, And they provide the primary timing source for the cell phones and the pagers.

The satellites provide in the flight phone communications on the airplanes, They are the main conduit of voice communication for the rural areas and the areas where the phone lines are damaged after a disaster, And they provide the primary timing source for the cell phones and the pagers.

The communications satellites have the ability to rapidly communicate between a number of widely dispersed locations, They help the big manufacturing companies and the department stores to perform inventory management, They provide the instant credit card authorization and automated teller banking services to even small towns, They pay at the pump gas at the freeway gas stations, and  video conferencing for the international corporations.

The astronomy satellites are the new technology that are mounted on earth orbiting satellites or on the deep space probes, and they can give us an unobstructed view with out the earth’s atmosphere interfering, They carry the detectors to record the electromagnetic radiation at wavelengths shorter than visible light.

The satellite-based navigation systems like Navstar Global Positioning Systems enable anyone with a handheld receiver to determine his location to within a few meters,They are known colloquially as GPS.