Satellites have many useful functions that help to better our lives.
Getting Up There
Satellites are launched into space in two different ways. Manned spacecrafts have taken satellites with them and released them when they reach the desired orbit. Some satellites are launched independently. These have rocket boosters that take the satellite to the proper altitude. The rocket then disengages itself from the satellite.
Uses
Satellites are utilized for a large variety of uses. Some are used for military intelligence or used for navigational purposes. Satellites can zoom in on very specific locations. This can be helpful in times of war to view military targets. The communications industry uses satellites for telephone, radio broadcast, and television broadcast. Weather information and atmospheric conditions can also be monitored and recorded by satellite. Lower flying satellites are commonly used for weather observations and scientific research.
Spacecraft such as the Space Shuttle are also considered satellites when they are put into orbit. These satellites only orbit the earth for a very short time and then return to earth under their own power. They orbit for many purposes such as gathering information for future flights and to conduct scientific experiments. Space stations are also satellites. They remain in orbit longer than the spacecrafts. The space stations are used for scientific studies that are hoped to help with new medicines and material usages.
Orbit
There are a few different types of orbits for satellites. They have an orbit much like our moon. They move at a very high rate of speed and are held in their orbit by the Earth's gravitational pull. If the Earth did not pull on the satellite, it would fly off into space in a straight line.
Geostationary orbits are when the satellite appears to be stationary. Satellite television companies utilize this type of orbit. The satellite is set to a speed where it keeps up with the rotation of the earth. Therefore a television customer can always count on their satellite receiver picking up a signal by pointing their dish in the same direction. Even though the satellite is in orbit and moving very fast, it appears to be stationary.
The solar synchronous satellite orbit goes around the earth from pole to pole. This orbit insures that the satellite on each trip around the planet will view a new slice of land. If you search for TerraServer on the Internet, you can input a location and see a satellite picture of the area of your choice. It is sometimes possible to find your home address and see your own house.
Coming Home
Once a satellite has burned out or died, we cannot get them back. They will remain in orbit. Some satellites will explode into smaller pieces that will also remain in orbit around the Earth. Very low orbiting satellites will sometimes re-enter Earth's atmosphere. Only about fifty percent of the satellite will burn in the atmosphere and the remaining pieces will fall to earth.
The satellites left in space may at one time become a large hurdle in space exploration. The pieces of satellites that have broken apart remain in orbit and move at very fast speeds. When a spacecraft is launched into space, it runs the risk of being hit by these pieces of space junk. Even a tiny speck hitting a spacecraft at high speeds could have a detrimental effect.
