Even its most enthusiastic planners at Bell Telephone Laboratories never
expected the sensation that Telstar caused. Although it was a deadly
serious venture—one of the steps along the way toward putting together a
workable satellite communications system—its success made it the
inspiration, among other things, of cartoons, jokes, and a couple of
popular songs. “Telstar” soon became a name recognized around the entire
globe. Stories about Project Telstar appeared in newspapers in almost
every language, in children’s books, in women’s fashion magazines.
[Illustration: _On July 10 and 11, 1962, people on two continents
saw these scenes on television at the same time, with the aid of the
Telstar I satellite_]
What caused all this stir in the summer and fall of 1962? The answer—now
that we look back on it—seems rather clear: For the first time, the
whole world discovered that satellite communications was really
possible—that peoples separated by oceans could now be united by live
television. Space had become an adventure, not just for lonely
astronauts, but for everyone right in his living room.
Project Telstar, of course, had more serious objectives:
—to prove that a broadband communications satellite could transmit
telephone messages, data, and television;
—to test, under the stresses of an actual launch and the hazards of
space, some of the electronic equipment that had been developed for
satellite communications;
—to measure the radiation that a satellite would meet in space;
—to find out the best ways to track a moving satellite accurately;
—to provide a real-life test for the special satellite communications
antennas and other ground station equipment.
To do its principal job—communications—the Telstar I satellite had to
receive a signal from a ground station, amplify it, and then retransmit
it on a different frequency back to other points on the earth. This
signal had to be strong enough and good enough to be received and
understood on the ground.
To do its secondary job—measure radiation and other conditions in
space—the satellite had to be equipped with special testing devices and
had to have a means of reporting facts about the environment it
encountered in space and the effects of radiation on solar cells and
transistors.
To let us know how well its equipment was working, the satellite had to
record and transmit a large number of measurements—including such things
as the temperature and pressure inside the satellite, its orientation
with respect to the sun, the current and voltage in various parts of its
electronic circuitry. Sending these measurements back to a ground
station is called _telemetry_.
To help with tracking, the satellite had to have a continuous radio
beacon signal that could be easily picked up on earth.
Finally, the satellite had to be able to control its equipment by means
of signals from the ground. To keep the solar power plant from being
overloaded, there had to be some way of “commanding” the satellite to
turn itself on or off. As you will read later, this was the one part of
the satellite that caused us the most headaches once Telstar I got into
orbit.