Page 57 - Communications Satellites Global Change Agents

C H A P T E R T W O

Satellite Technology: The Evolution

of Satellite Systems and Fixed Satellite Services

Louis Ippolito
ITT Industries
Joseph N. Pelton
The George Washington University

The synchronous satellite is an absurdly simple idea, and involves no real
paradox. It is not really motionless, for it is actually moving along its orbit at
almost seven thousand miles an hour. At this precise speed it just keeps up
with a point on the earth's spinning equator, far below and it just overcomes
the pull of gravity as well.
—Arthur C. Clarke (1967, p. 140)

One can begin the story of satellite technology in many different points in history.
For example, in the third century BC, Arcetus of Tarentum developed a working
concept of jet propulsion on which today's rockets are still based. This remark-
able achievement used steam and his projectiles were wooden pigeons, but the ba-
sic physics are still much the same at the start of the 21st century. However, these
basic concepts on rocket propulsion were to be lost in the centuries that followed
the remarkable discoveries of Arcetus.
Some 20 centuries later, none other than Sir Isaac Newton published the first
theoretical account of how an artificial satellite could be launched into earth's or-
bit. In his discussion about physics and gravitational effects, Newton actually
drew a diagram showing how an artificial satellite could be launched into earth's
orbit. He maintained that this feat could be accomplished with the "moral equiva-
lent" of a large cannon that had sufficient launch velocity (i.e., muzzle velocity)
and the right elevation angle.
Many other visions of satellite networks followed the writings of Newton, both
in works of fact and fiction. H. G. Wells, Everett Edward Hale, Jules Verne,
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