TACSAT, Jolly Giant Built by HAC, in Orbit and Operating Well—Hughes News February 14, 1969

The world’s largest and most powerful communications satellite, built by HAC for the Department of Defense and launched Sunday from Cape Kennedy by the Air Force aboard a Titan-3C booster, now is in synchronous orbit over the Pacific.

         HAC Program Manager Tom Mattis and other Hughesites who witnessed the launch described it as “beautiful, beautiful, adding “it was a glorious day for it.”

         All the tests scheduled to be completed by Wednesday had been accomplished and all systems were operating well.

         The 1600-pound experimental tactical communications satellite (TACSAT), two stories high and more than 8 feet in diameter, carries a cluster of antenna systems capable of radiating signals that can be received by all types of ground terminals including those with antennas as small as 1-foot in diameter.

         Construction of the spin-stabilized spacecraft, built under a USAF contract totaling $30 million, was directed by the Air Force Space and Missile Systems Organization (SAMSO).

         The giant satellite will be used by the Army, Navy and Air Force to test the feasibility of suing synchronous satellites for tactical communications with small mobile ground stations, aircraft, and ships at sea.

         Mr. Mattis said the tests will determine whether hundreds of small mobile terminals with varying power levels can be used effectively with a single satellite.  Another objective of the mission will be to determine the best frequency bands to be used for tactical service.  The tests will be in the ultra high frequency (UHF) and the super high frequency (SHF) ranges.

         The satellite’s communication antennas are mechanically “despun” to keep them pointed toward earth.

         “The new satellite,” Mr. Mattis said, “will test for the first time in space a new Hughes concept of stabilization called “Gyrostat” which defies the theory that all spin-stabilized satellites must be “short and squat” and look like over-sized hat boxes.”

         Heretofore, satellites have been designed for the inertia characteristics of a disc rather than a rod.  The Gyrostat principle, however, is designed to permit stabilization of long slender bodies.

         Some Parts Spin

         The new principle holds that satellites can spin around their minor axes and permit some parts to spin while other parts remain stationary, with never a wobble in the spacecraft, he explained.

         The concept not only permits variations in the length configuration of communications satellites, thus allowing full utilization of the booster shroud, but it also enable important payloads, such as antennas or telescopes to remain stationary so that they may be precisely pointed in any direction.

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