Living In Space

Living In Space:
Energy Space is filled with radiant energy and
beyond earth\'s atmosphere this energy flow more
steadily and more intensely from the sun than that
which penetrates to the surface of the Earth. So an
abundant and essential source of energy that
would be used in space for the space colony
would be solar radiation by developing satellite
solar power stations. To live in space, humans
must be protected from the fierce intensity and
penetrating wavelengths of unattenuated sunlight,
but this same energy is one of the primary
resources of space. The colony will have to have
enough energy to maintain a fairly uniform
temperature even though it is apace. The sun
shines twenty-four hours a day and is not dimmed
by an atmosphere. Shaded materials not exposed
to direct sunlight will almost be at absolute zero.
While the temperature in closed bodies exposed
to the sun can soar above the boiling point. The
colony will need to have both heaters and air
conditioners. On the other hand, this sun\'s energy
can be converted into electricity in the colonies. It
will be converted with ten percent efficiency to
electrical power which is sold at a rate of .012
kw/hr, a square kilometer of space would return
more than $14,000,000 each year. Converting
solar power to electricity in space, we would build
satellite solar power stations that would intercept
the sunlight and convert it into electricity. The
satellite solar power stations would intercept
enough sunlight to replace five nuclear reactors or
coal plants. The stations could be as big as nine
miles long and four miles wide and it would only
weigh twenty thousand tons. It would be built with
hollow triangular girders made of aluminum that is
very fast and easy to build . Solar power satellites
are a pollution free way to generate electricity and
cost no more than coal or nuclear energy. There
has been twomajor designed stations made so far.
One is designed by Peter Glaser of Author D.
Little Inc., which would use very large arrays of
photo voltaic cells to make the conversion directly
into energy. The other major design is by Gordon
Woodcock of Boeing Aircraft Corporation,
proposed having conventional turbogenerators
operating on a Brayton cycle with helium as the
working fluid. The key product in the solar power
stations is solar cells, which does the actual
converting of energy into electricity. A useful
material is found in lunar soil is silicon which is
used to make solar cells. So we can produce a
large amount of these cells and then we can avoid
any problems of shipping the material from earth.
Cells convert sunlight directly into electricity and
this could be used to supply the electricity for the
construction and operation of the space colony. It
would be simple to put together large scale solar
collectors and mirrors around the colony. A solar
cell is made from two thin layers of material,
usually silicon, which has been prepared in a
special way. The net effect of this arrangement is
that the sunlight falling on the cell shakes the
electrons loose in the material, then these electrons
move off into an outside circuit, which is detected
as an electrical current. Things are arranged so
that most of the work involved in generating the
electricity is done by forces associated with the
atoms themselves, with no energy input other than
sunlight. So getting energy from the sun would
seem pretty easy. All we\'d have to do is just make
enough solar cells to collect the amount of energy
we need, put them in the light, and sit back and
watch the electrons flow. In space sunlight is a
pretty diffuse form of energy and that could cause
some problems. Even if we could convert sunlight
to electricity at one-hundred percent efficiency, it
would take a sheet about three feet on a side to
power an ordinary toaster. This is why designers
of solar power satellites are driven to talk about
very large structures.Solar cells can never convert
all of the sunlight that falls on them to electricity.
The reasons for this is depended on the basic laws
of physics. Only about one-third of the sunlight
falling on a cell comes in forms whose energy is
not great enough to move the electron. This means
that one-third of the sunlight hitting the cell will
never get converted into electrical energy, but will
just heat the cell. There is one drawback in today\'s
technology of the solar power satellite stations.
The conventional solar panels are at best only
thirty percent efficient, and can seriously be
eroded by atomic oxygenic the upper reaches of
the atmosphere. Their repair will depend on
regular Shuttle flights: if these are interrupted,
serious power shortages may result and
experiments, or even habitation modules, may
have to abandoned.