Digital matrix intercom ties together launch operations for Orbital Sciences

Engineers at Orbital Sciences Corp. in Dulles, Va., the company that provides low cost access to space, needed to upgrade their global communications system to enable all the participants in launch operations to coordinate their activities in real time - and the system had to be compatible with their customers.

Last year company engineers chose the Matrix Plus digital matrix intercom system from Clear-Com Intercom Systems of Berkeley, Calif., on the recommendation of experts at NASA`s Goddard Space Flight Center in Greenbelt, Md. NASA officials have used the same system for several years.

The purpose was to enable senior executives, employees, and investors to monitor launch communications without being tied directly into two-way communications routes. Orbital Sciences officials had tried telephones, supplemented with speakerphones, but considered them unsatisfactory in high-noise areas.

Clear-Com designers manufactured the hardware, which runs $1,000 to $3,000 per station, says Gary Parks, the company`s marketing manager. Doing installation and checkout was Systems Wireless, a value-added retailer in Herndon, Va. The system was installed at Orbital`s own tracking station in Fairmont, W.Va., and interfaces directly with two other government tracking stations at the Poker Flats Range in Alaska and the McMurdo Ground Tracking Station in Antarctica. Other participants during launch operations are usually technicians at Vandenberg Air Force Base in California, and NASA`s launch facility on Wallops Island, Va.

J.T. Tomlinson, the system designer at Systems Wireless, programmed a set of communications paths, all routed from the sources through the Matrix Plus intercom card frame. He also created a virtual audio mixer within the matrix to provide launch audio to others outside the launch team.

Two features of this system differentiate it from the typical matrix intercom, Tomlinson notes. First, this installation "mixes the ground launch and operational feeds through the matrix to all the outlying listen-only sites." The second "non-standard treatment" is the system`s ability either to address ground stations individually, or tie them into a single party line, as they are during launch.

Designers achieved the sophisticated signal routing by creating several virtual on/off switches within the Matrix Plus system configuration software and assigning them either singly or in groups to physical switches on an AP-22 panel.

The 20-key AP-22 Matrix Plus assignment panel provides the physical control of the routes, turning them on or off and routing one-way audio feeds and two-way intercommunication to the needed destinations. Orbital experts have launched four satellites since completing installation last August. John Cavallo, the company`s program manager for the ground tracking station, credits Matrix Plus with improving his company`s communications efficiency ten-fold. - J.R.

For more information on the Matrix Plus system, contact Mike Goddard, national sales manager at Clear-Com Intercom Systems, by phone at 510-527-6666, by fax at 510-527-6699, by mail at 945 Camelia St., Berkeley, Calif., 94710-1484, or on the World Wide Web at http://www.clearcom.com

The Matrix Plus digital matrix intercom system from Clear Com Intercom Systems in Berkeley, Calif., coordinates the launch operations for Orbital Sciences Corp in Dulles, Va.