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February 1997



Deep space probes
talk to Tech alumnus

JPL photoWhen NASA's space probes encounter comets or asteroids, or fly by planets and gather information, Deep Space Network antennas must be ready to collect and amplify signals that can be one thousand billion times weaker than a commercial television signal arriving at a home. Making sure that happens is the responsibility of Virginia Tech alumnus Brad Reed (EE, '88).

An employee of AlliedSignal, Reed is the Lead Antenna Systems Engineer, with overall maintenance and engineering responsibility for the NASA/JPL Goldstone Deep Space Communications Complex. He works with 20 other engineers at the facility in California's Mojave Desert.

"Among other missions, we're now tracking Ulysses, Voyager, Mars Pathfinder, and Galileo - and we're still tracking Pioneer 10 and 11, which were launched in the early '70s and are now at the edge of the solar system," he said. "We can lock on Pioneer 10, but the spacecraft's signals are too weak to receive because of the great distance. It takes about 12 hours at the speed of light for the radio signal to get here from both Pioneers."

To enable such tracking, each complex has antenna arrays including a 70-meter antenna, several 34-meter antennas, and 26-, 11-, and 9-meter antennas. They range in age from those built to support the Apollo program in the 1960s to newer high-efficiency systems.

The Goldstone Deep Space complex involves 11 beam wave guide and Cassegrain antennas and serves as the testbed for new equipment and development. "It's my responsibility to keep them all up and running," Reed commented. This involves a multidisciplinary mix of electrical and mechanical engineering skills. For example, the surface of the 70-meter reflector is maintained within an RMS accuracy of .25 millimeter across an area of 3,850 square meters.

Another example of the mix of skills needed was an episode concerning the November 1995 Galileo encounter with Jupiter. "Just prior to the encounter, we were optimizing the DSS-14 antenna, and noticed electromagnetic noise problems. The systems transmitters and receivers were checked and found to be operating properly. Then we began isolating and checking other possibilities. We found that a hoist on a quadripod leg of the antenna had been recently installed to perform maintenance work - within the radio wave path - and was creating enough noise so that it needed to be removed."

What would be a very bad day? To be communicating with a spacecraft or probe in a high visibility mission and have power failures, software glitches or component failures. "We operate in real-time, and if we lose the data, depending on the mission, it may be lost forever."

Much of Reed's work involves analyzing and determining the reliability and maintenance routines for the equipment. The ideal is a balance between replacing parts too soon, or letting them run until they fail.

He has also been instrumental in AlliedSignal getting ISO 9001 certification at the site. "One interesting problem we've run into involves recreating the knowledge base on the technology developed for the Apollo program," he said. "The Apollo program involved many, very bright people who left NASA during the 1970s and 1980s. We now need to recreate the knowledge that was lost with their departure. This involves determining how the equipment and processes work and why those particular designs were selected, and then developing plans to maintain or upgrade the equipment."

Reed brings a strong management and systems engineering background to his current position. He has recently earned an MSME degree from California State Polytechnic University of Pomona, and spent three years running a start-up company that produces solar arrays for small satellites before joining the Goldstone complex.

He has maintained his ties to Virginia Tech since his graduation in 1988. In his first position, as a research engineer for Applied Solar Energy Corporation, he arranged for his company to donate $100,000 worth of space-grade solar cells for Tech's first solar car, the SolaRay 1. He has followed the solar car team's successes ever since.



The Bradley Department of Electrical Engineering
Virginia Tech

Last Updated, May 5, 1997
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