Morelos uses new design Hughes News December 21, 1984 Transcribed by Faith MacPherson

A new antenna design introduced on an HS 376 satellite for Mexico may have a far-reaching impact on future spacecraft. Mexico’s Morelos communications satellite, designed and built by Space and Communications Group, is the first commercial spacecraft that uses a streamlined antenna design, consisting of a single reflector system to operate in both C- and K-band frequencies.

All SCG commercial spacecraft, with the exception on Intelsat, operate in only one of the two major communications bands. The new Intelsat VI series, being built at SCG to serve a consortium of 106 countries, uses a multiple-reflector system to enable the giant satellite to operate in both bands. On Morelos, the additional reflector has been replaced with a planar array, a simple beam configuration that has been used for decades on radar systems.

On a relatively small domestic communications satellite such as Morelos, multiple-reflector systems can create potential deployment, structural, and alignment problems. The planar array, which is 1-inch thick by 1 ½-feet tall by 3-feet wide, replaces a K-band receive reflector that would have been approximately 3 feet by 6 feet.

Senior project engineer Tim Crail, originator of the new application for the old planar array technique, saved the company $1.2 million with his proposal. The idea earned him recognition as the top Cost Improvement Program participator in SCG for 1983.

Mr. Crail’s simple solution to a complex problem was a boon to the performance capabilities of Morelos, enabling clear reception in both C- and K-band frequencies. “Never to my knowledge has the planar array been used to generate a highly contoured beam that will illuminate specified land masses,” said Mr. Crail.

A patent disclosure naming Mr. Crail and staff engineer Sandy Shapiro as co-inventors of the new antenna system is pending approval in the U.S. Patent Office. “The patent could be very significant,” said Mr. Shapiro, a major contributor to the conception and development of this antenna.

“One of the advantages of the modularized phased array antenna design is that it could be reused for many applications in the same frequency band,” he explained.

The planar array will give Mexico the first satellite that has a direct- radiating antenna system.

The satellite’s high-performance capabilities also were accomplished through the design and development efforts of senior scientist Tom Hudspeth.

In appreciation of the satellite’s unique capabilities, the customer has selected the outline of the antenna system as a major part of the design for the Morelos emblem.








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About Jack Fisher

Jack was a systems engineer at Hughes from 1961 to 1992. He contributed to various programs including Surveyor, Pioneer Venus, Galileo, Intelsat VI and innumerable proposals. He was the manager of of the Spacecraft Systems Engineering Lab until his retirement. Upon retirement Jack taught systems engineering at a number of national and international venues.