Word: antennas
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...have borrowed a technique that radio astronomers use to study the sun and the planets. They are tuning in on the faint thermal radio waves that are emitted by every natural body, whether celestial or earthly. At altitudes of less than 1,000 ft., a pair of highly directional antennas pick up that radiation from objects below the plane. And since one antenna points behind the other, it picks up the same radiation at a slightly later time. That time lag, along with the plane's altitude, supplies enough information for an on-board computer to calculate the plane...
...crosswind is causing the plane to drift sideways, the pilot may have to swing the rear antenna to right or left before it picks up the proper pattern of ground radiation. In that case, the amount of antenna swing is also fed into the computer, which then cranks the drift angle into its computations. Working with direction, ground speed, drift angle and flight time from a known point of departure, the pilot's computer becomes an accurate navigator...
...flying windmill. The spacecraft, freed from a cocoon-like covering, unfolded the four solar panels that powered its instruments by converting the sun's energy into electricity. With those panels deployed, it measured 22 ft. 7½ in. across and 9½ ft. to the top of its antenna. Curving into a wide-swinging, elliptical orbit that was precisely plotted in advance, the ship set out to intersect the orbit of Mars at a predetermined time...
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...
Even before Early Bird reached its final station, it went to work. American Telephone & Telegraph's great horn antenna at Andover, Me., which is now leased by Comsat, sent a television test pattern up to the satellite. Back the pattern came to Andover, its quality so good that Siegfried H. Reiger, Comsat's technical vice president, proudly told a press conference: "The television capability of the Early Bird satellite is established...