Capacity of Hughes Satellite Dwarfs Its Predecessors
HAC has been awarded a $72 million contract to build four ot the world’s largest communications satellites, each having a potential communications volume 25 times greater than any satellite now in service and more capacity than the combined communications satellites now in operation.
The contract for the new Intelsat IV satellites was awarded by the Communications Satellite Corporation on behalf of the International Telecommunications Satellite Consortium.
“The new spacecraft, 8 feet in diameter and nearly 18 feet high, will be designed to carry in excess of 5000 two-way telephone calls, transmit 12 color TV broadcasts simultaneously , or any combinaton of different kinds of communication transmission,” said Senior Vice President John H. Richardson, Aerospace Group executive.
The huge synchronous-orbit Intelsat IV will be the fifth generation of satellites built by Hughes since the tiny Syncom 2 was launched in 1963 to usher in the era of continuous satellite communications. The HAC satellite lineup includes the Early Bird, Intelsat II, tactical communications satellite, and two Applications Technology Satellites.
Intelsat will be able to focus power into two “spotlight” beams, which can be pointed at selected areas, providing stronger signal and more channel capacity in heavy communications traffic areas.
“For transatlantic transmission, the bems could be aimed at Western Europe and the eastern United States, or they could be used to link South America with Europe,” Mr. Richardson said. “In a north-sout lineup, North and South America could be linked.”
The spotlight effect is made possible by two steerable dish antennas on the satellite which can be controlled on command from earth. The satellite could be moved anywhere along the equator and its antenna beams repositioned to point at selected areas.
Two other antennas on the satellite will provide communications coverage to areas outside the spotlight beams. Ground controllers will use electronic switching to adjust the power going into each of the two antenna systems.
The effective radiated power of up to 3000 watts per spot beam channel will permit many more ground stations to use the satellite, making less expensive satellite communications possible.
The satellite is scheduled for delivery in about two years, Mr. Richardson said It is designed for launch into a 22,300-mile synchronous orbit by a Titan-IIIB/Agena or Atlas-Centaur booster. The liftoff weight is expected to be 2452 pounds, and the satellite will be spin stabilized.
Foreign Nations Help
Companies from 10 member nations of Intelsat will participate extensively in the fabrication and testing of the satellites, Mr. Richardson said.
The first flight spacecraft and its subsystems will be built and tested at the El Segundo Site, with member-nation subcontractors participating. The second spacecraft will be assembled and tested at HAC, but most of the subsystems will be built by the subcontractors.
The third and fourth flight spacecraft will be assembled at British Aircraft Corporation in Bristol, England, using subsystems provided by the subcontractors. The two spacecraft will be shipped to Hughes for final testing.
Major subcontractors are in the United Kingdom, West Germany, Switzerland, Belgium, Japan, Italy, Sweden, Spain, France, and Canada.