Energy of Satellites
Ian B. / Physics 336 / 7 April 1997
Artificial satellites get the energy they use from many different sources.
Satellites can use their energy and power to serve a variety of purposes.
The energy and signals which satellites give off affect and improve our
lives in many different ways.
Selene's Laser Power
There are many different ways in which artificial satellites obtain
the energy and power they need. One new way of giving satellites energy
and power is through the use of a laser. This new system is known as SELENE
which stands for Space Laser Energy. SELENE will be used to move satellites
from an orbital position to another. It will do this by using a laser powered
Space TugÎ. The Space Tug will be used to retrieve satellites in
need of repair to be fixed at the International Space Station which will
be built soon. The Space Tug gets its power from a ground based free electron
laser and the laser is beamed to it through the use of an adaptive optics
telescope. The energy beam is then stored by the Space Tug as electrical
energy. Space Tug will be able to move satellites, which have been put
into the wrong orbit, into the correct orbit. It will be able to bring
disabled satellites into a lower orbit also, so they can be retrieved by
Space Shuttles (Spellman).
Satellites Use Solar Energy
A satellite can receive its energy and power through the use of solar
energy also. Solar energy comes from thermonuclear fusion reactions which
occur in the sun. There are many different types of collectors which gather
the solar energy. Photoelectric panels have been used to give power to
satellites. By using photoelectric cells, or solar cells, solar energy
can be changed into electricity. For as long as the light shines on the
cells they will produce electrical voltage (Compton's Interactive
Satellites Use Nuclear
Another method used to give satellites energy and power is by the use
of nuclear power. Nuclear power produces enough energy to operate a Space
Tug as well as the laser power. Solar power, unfortunately, does not produce
enough energy to operate the Space Tug. But nuclear power is often very
hard to get licensed (Spellman).
Satellite Energy Benefits
Satellite energy can be used to benefit humans in many ways. Satellites
can radio information down to Earth. This ability has been utilized to
use Global Positioning Systems (GPS). Global Positioning Systems can be
used for many purposes. GPS are used to find locations on Earth. A series
of three satellites are needed to find a precise location on Earth. GPS
satellites send data to Earth every thirty seconds on its location, velocity,
and when it was transmitted. This information can be used to figure out
how much time the signal took to get to your receiver from the satellite.
When this is figured out, the distance between the satellite and receiver
can be found. This process is very accurate. The signal that is used for
civilian use is accurate to 76 meters. Although this is very accurate for
most purposes it is not accurate enough to be used for the automated landing
of a 747 air plane or to find other precise locations that might be needed
for other purposes. Other methods have been developed combining information
from Global Positioning Systems with other signals from land based stations.
These have been developed to narrow down the position to about 1 meter.
This system is called Differential GPS. A system known as Survey GPS is
even more precise. This system can be used to find a position down to millimeters.
These measurements are so accurate they can be used to measure such thing
as continental drift or changes in ocean levels. These systems can be used
for commercial uses like automobile navigation systems. Automobile navigation
systems like these are popular in Japan, and will become an option in US
cars as well (Rozmiarek).
Commercial Use of Satellite
One such car company that uses satellite energy in the form of Global
Positioning systems is Cadillac. Their system is known as Onstar. It utilizes
satellite technology to aid people. It will use Global Positioning Systems
to help people and possibly save their life. If the airbag in the vehicle
deploys, a signal is sent. If staff are not able to communicate with the
people in the car, emergency help is then sent. This is only of the many
things Onstar utilizes GPS to do. This service, which uses satellite energy,
can be used for navigation assistance. They can also be used to unlock
the doors if the keys are locked in the car, and the car can be tracked
if it is stolen. All this is made possible by a Global Positioning System
antenna and the Onstar transmitter/receiver. The use of satellite energy
through things like Global Positioning Systems is used to help us in a
variety of ways. It has made our lives a lot easier and can save and protect
us (World of Wheels Online).
Demeis, Richard. Satellite. Compton's Interactive Encyclopedia. CD-ROM.
New Media, 1995.
Spellman, Jim. Selene! A New Space Utility; Laser Beaming Power
into Space. Space
News Dec. 1996.
Rozmiarek, Andrew. Global Positioning System WIRED 3.10:Geek Page.
ÍHelp on the way with Cadillac's Onstar. World of Wheels