Functions of a Satellite
James H. / Physics 337 / April 17, 1997
A satellite, in today's world has many different applications in many fields.
Although before artificial satellites were invented a satellite was known
as the moon or other planets. The moon is a satellite of the earth, it
orbits around the earth due to the gravitational forces of the bodies.
However, today when people hear the word satellite they thing of man made
objects orbiting around the earth. Which is true and in the rest of my
paper I will tell you exactly what a satellite is.
What is a satellite ?
An artificial satellite is a man made object placed into orbit around the
Earth for the purpose of scientific research, weather reports, or military
reconnaissance. Scientific satellites are set into orbit to observe the
space environment, the Earth, the Sun, stars and extra galactic objects.
These satellites have retrieved a huge amount of information helpful to
scientific research. Weather satellites are used every day for meteorological
forecasts and in shipping. Also military satellites play a important role
in today's modern military. Satellites are extremely important today. All
artificial satellites have certain features in common. They all include
radar systems, sensors like optical devices in observation satellites and
receivers and transmitters in communication satellites. Solar cells are
used to generate power for the satellites and in some cases ,nuclear power
is used. All satellites need altitude-control equipment to keep the satellite
in the desired orbit.( Grolier Encyclopedia). All this information should
answer the question what is a satellite.
Orbit of a Satellite
The orbit of the satellite is achieved when it is given a horizontal velocity
of 17,500 mph at sea level causing the Earth's surface to curve away and
as fast as it curves away gravity pulls the object downward and at this
point the satellite achieved orbit. As the altitude of the satellite increases,
its velocity decreases and its period increases. The period of satellite
is the time the satellite takes to make on revolution around the Earth.
Satellites in later orbit are called synchronous satellites. If the satellite
orbits in a equatorial plane, it is called geostationary which means it
is always over the same place on earth at all times. This form of orbit
is used in weather for reports of a certain area at all times.( Grolier
Encyclopedia ) The orbit of a satellite is very scientific but not hard
Repairing a Satellite
Most people would think how can you repair a satellite when you are on
earth at it is in orbit above you in space. the only possible way to repair
satellites is to go into space and get them. That seems like a hard task
almost impossible although it is hard today it is capable by space shuttle.
The astronauts have to grab hold of the satellite by the arm in the shuttle
then lock down the satellite in the shuttle's payload pay. The next step
in the process would be to make a series of space walks by the astronauts
to repair or in some cases replace malfunctioning systems.( World Book
Most likely after a satellite is placed in a sufficient orbit it will stay
on course although, if it does lose its orbit it can not fall back down
to earth. But don't worry. The satellite slows down due to air fiction
as gravity begins to pull the satellite down. The particles surrounding
the satellite and the pressure from the sun's energy will cause the satellite
to burn up. On the other hand, if satellite goes off course, in the opposite
direction, it will continue to float in space and just became another piece
of space junk. The is no reason to fear runaway satellites. The only person
to worry is the one that paid for the satellite. ( World Book )
This should have supplied you with information about the functions of a
satellite. Which includes, the different orbits of a satellite and the
results of a dead satellite. Also the difficulty of repairing a damage
satellite. Almost every field is enhanced by the use of artificial satellites.
Satellites have help improve our technology a great deal.
"Satellite, Artificial". Grolier Multimedia Encyclopedia. CD-ROM.
"Satellite, Artificial". World Book Multimedia Encyclopedia. CD-ROM.