
 oi	8tT   Approximately 15,000 man made objects have been
placed in orbit since Sputnik I was launched in 1957. As of
30 October 1985 - 5,783 are still in orbit. Almost 
three-quarters of these objects are space debris, or
"space junk." Of the 1,500 or so objects not considered
junk, only about one-fifth are operable.
   Some of these objects may be satellites (in some form 
of orbit), or probes which may fly by or land on another
celestial body. In general these devices can be grouped
by function:


COMMUNICATION SATELLITES:
   The first true communications satellite, Telstar I funded
by AT&T, was launched into low Earth orbit on 10 July
1962. Since that time communication "live via satellite"
has been accepted as part of everyday life. Telephone,
television, radio, and telex have all improved dramatically,
becoming more efficient and less expensive through the
use of the present day Intelsat, Westar, Telstar, SBS, and
Galaxy satellites. The military uses these and dedicated 
military communications satellites for their command and
control networks.


NAVIGATION SATELLITES:
   Today's navigation satellites allow a soldier on the
battle field to pinpoint his location to within 2 meters,
position a ballistic missile submarine (or its missiles in
flight), guide a freighter through a reef, or allow a sailor
to know his position day or night, rain or shine.


SCIENCE SATELLITES:
   Weather reporting, atmospheric research, cartography,
agriculture, oceanography, forestry, mining, earthquake
detection, solar and planetary probes - these are just a
few of the scientific uses in which satellites are
employed. The first weather observation from space was
via a family of satellites known as TIROS (Television and
Infrared Observation Satellite), launched in the period
from 1960 to 1965. The weather satellite is now an
established tool of the meteorologist in most countries of
the world. The study of weather and the atmosphere
prompted scientists to look more closely at other
planetary uses (as those listed above) and inspired the
creation of a whole family of Earth resource satellites.
The U.S. made initial launches with the Landsat and Seasat
series and the U.S.S.R. launched the Salyut and Cosmos
series.


ENGINEERING ACTIVITIES:
   Engineering experiments are carried out using various
special purpose satellites, probes, habitats, and Orbiter
flights. The Surveyor probe tested soft landing techniques
for the Apollo lunar landings, the Long Duration Exposure
Facility (LDEF) allows material testing, and the 
SkyLab/SpaceLab flights conducted important materials
research. Construction experiments were tested and 
performed in the first Skylab and during several Orbiter
flights. In the case of the Skylab program the
construction performed was for actual use; if the
techniques had failed the program would have failed.


SPACE PROBES:
   Orbital space exploration began in low Earch orbit with
Sputnik and Explorer satellites in the late 1950's. During
the 1960's spacecraft orbited and landed on the moon
while others approached Venus and Mars. The 1970's saw
additional planetary exploration of Mercury, Jupiter, and
Saturn by the Mariner, Pioneer, Viking, and Voyager
probes. The 1980's witnessed the fly-bys of comets,
asteroids, and a visit of Voyager 2 to both Uranus and
Neptune. the world's first engineering study of an
unmanned "starship" (named Daedalus) was made
between 1973 and 1977 by a technical group of the British
interplanetary Society. Just as the early satellites helped
to perpare us for space walks and moon landings, so too
these deep space probes will provide information to help
prepare for the time when starships will no longer be
science fiction, but a reality.

MILITARY SATELLITES:
   From the beginnings of space flight military uses have
been saught for space vehicles. The Military employs a
great deal of the available capacity of the navigation,
weather, and communication satellites. In addition, 
distinctly military applications are pursued such as
reconnaissance and targeting. The U.S. Discoverer, Big
Bird, Vela, and Key Hole satellites are known to be related
to these activities, as are many Russian Vostok and
Cosmos flights. The names of any current military
vehicles are closely guarded secrets as demonstrated by
the cloak of secrecy around recent Space Shuttle flights.
   ASATs (Anit-Satellite systems), designed specifically
to destroy satellites or to significantly impair their
performance, came into being in the middle to late 1960's.
These have been tested and/or used by both the U.S. and
U.S.S.R.  Since much of the world has come to depend upon
satellites for both civilian and military applications, a
large debate has centered on the development of these
types of defense systems, the most controversial being
President Reagan's Strategic Defensive Initiative
(commonly called "Star Wars"). Most ASAT weapons are of
the "kamikaze" variety: that is, they collide with the
target in order to destroy it. Current research is being
conducted by both the U.S. and U.S.S.R. on laser and
particle beam weapon systems. Lasers inflict damage by
heating a target's sensors, antennas or power systems.
Particle beams destroy an object by focusing high
amounts of energy and radiation on the target. This
energy tends to heat the target, like a laser, and the
radiation ruins the electronics.
   America's Space Shuttle has considerable military
significance. It is thought that it may be used for
external inspection and possible internal examination of
the components of most low orbiting satellites. This is
understandably considered "unacceptable espionage" by
most other countries. The next generation of U.S.
reconnaissance satellites is being designed for
deployment and recovery by the Shuttle System. To outfit
any of the Shuttles with real weapons is unlikely as the
Orbiters are very fragile and few in number.

