Electronics: The Room-Size World

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Synchronous satellites, such as the Hughes men wanted to build, have much in their favor. Best of all, they seem to hang in one spot in the sky. But they also have two strikes against them before they take to space. They must be kept as light as possible because of the great rocket effort needed to place them on their high orbits, and in spite of their lightness, they must transmit a radio signal strong enough to be heard at that great distance. Perhaps more serious is the problem of keeping them on station above a selected point on the earth's equator. They are continually pushed out of position by irregularities in the earth's gravitation, by the influence of the sun and moon, and even by the infinitesimal pressure of sunlight. They must carry propulsion devices that will always be ready to nudge them back in place again. These obstacles were formidable, but Rosen & Co. were not daunted.

Syncom I, the Hughes-built oldest brother of Early Bird, reached its orbit in 1963, but an exploding tank of high-pressure nitrogen kept it from succeeding electronically. Syncom II and III, used by the Department of Defense, were successful, but their performance has been kept partially secret. Early Bird, the fourth of the series, was built and launched for Comsat, the private company that was created by Congress to set up a commercial communication-satellite system. In the Syncom family, Early Bird was the big, public success.

Rosen was moved to compose a ditty to the tune of Bye, Bye, Blackbird:

Pack up all your cares and woes,

Retire all those old servos, Bye, bye, tracking.

Get rid of all those rusty gears,

Early Bird will end your fears, Bye, bye, tracking.

So sell your stock in RCA

And buy some Comsat right away,

Tracking, bye, bye.

So many investors have apparently taken Rosen's advice about Comsat stock since it first went on the market last June, the price rose from 20 to a high of 66¼ this year.

Left Turns. Early Bird is a miracle of delicate electronics and advanced space-craftsmanship. The first problem was how to get it into an equatorial orbit from Cape Kennedy. If the cape were on the equator, Early Bird's rocket would have been asked only to carry it to the desired height and push it up to the proper speed—about 7,000 m.p.h. But the cape is 28° north of the equator, so Early Bird had to make a more complicated maneuver, turning sideways when it reached orbiting height. This left turn in space was accomplished nimbly, and ever since, Early Bird has kept itself on station by firing delicate burps of steam from its hydrogen-peroxide thrusters.

Early Bird's curved sides are covered with 6,000 solar cells to supply electric power, and the satellite spins like a gyroscope to keep stabilized. One short antenna receives radio signals from the earth. They are fed to a transponder which amplifies them and then transmits them back to earth. Much of the transmitted energy is lost in space, but enough reaches the earth to be picked up by powerful receiving stations in the U.S. and Europe and amplified once more before being transmitted to home receivers.