Telstar and Fifty Years of Connectivity
Guest column by Louis J. Lanzerotti, editor of Space Weather (published by AGU), distinguished professor at the New Jersey Institute of Technology, and AIP Governing Board chair; and Gregory A. Good, director, Center for History of Physics
This morning, without a second thought, people around the world checked their email on some smart phone, or watched a live TV broadcast on some news channel from someplace where the Sun sets when it is rising here. Our daily lives and worldwide commerce depend on and are utterly shaped by hundreds of satellites. Couldn’t we always see hurricanes from above? Couldn’t we always conduct business around the clock? Didn’t we always have GPS direction guidance? Couldn’t we always measure radiation and electromagnetic fields in space and anticipate the possible effects of solar events on our lives and our technologies? Satellites enhance the senses of the human race, and they link us ever more inextricably together.
More than fifty years ago, on July 10, 1962, the United States launched Telstar, the first active-communications satellite. Last July, a celebration of the anniversary brought together a number of scientists, engineers, and others involved in this achievement at Alcatel-Lucent Bell Laboratories. (See the synopsis video on You- Tube.) One of the authors of this article, Louis Lanzerotti, joined Bell Laboratories in 1965 because he was attracted by the opportunity to analyze Telstar data and to work on the design and implementation of a Bell Laboratories radiation detection instrument. This device would be incorporated in the first NASA test communications satellite at geosynchronous orbit, ATS-1, launched in December 1966.
Telstar’s anniversary celebration belonged at Bell Labs, which was central in the conception, design, build, launch, and follow- up of the project. Telstar was funded by the AT&T Company and built by Bell Laboratories; AT&T reimbursed NASA for the launch costs. Telstar used the latest transistors (all discrete components!) and maser amplifiers, a new technology. Telstar received signals, amplified them, and retransmitted them.
The first public images transmitted across the Atlantic in 1962 were of the Statue of Liberty and the Eiffel Tower, followed by part of a Philadelphia Phillies vs Chicago Cubs baseball game. Telstar had started a new age of communications. By 1965, half a dozen similar satellites were actively relaying signals. More Telstars were orbited in the 1980s, 1990s, and on. The die was already cast for CNN and ESPN!
Telstar also, however, carried solid-state detectors with different levels of shielding for detecting electrons of different energies in orbit. These were designed and included to specifically study the effects of the space environment on transistors. Unknown to the Bell scientists and engineers who built Telstar, the United States launched one of its last near-space nuclear tests on July 9, the day before the satellite’s launch. Project Starfish Prime exploded a hydrogen bomb 250 miles (400 km) above Earth’s surface, a thousand times more powerful than the bomb used at Hiroshima. The blast created an electromagnetic pulse much larger than expected, damaging electrical and communications infrastructure in both Hawaii and New Zealand. It also produced an artificial radiation belt approximately 100 times the natural Van Allen Belt intensities and soon degraded the electronics on Telstar, leading ultimately to its failure in February 1963. Its life spanned a mere six months. Nevertheless, the takeaways endure and led the way to modern communications.
One Bell researcher who attended the 50th anniversary of Telstar, physicist Walter Brown, led the efforts at Bell Labs to “harden” the transistors and other electronics that were used in Telstar. As a result, Brown was well positioned to study the lifetime of high-energy electrons produced by Starfish Prime. His results are still used today. Ironically, the confluence of Starfish Prime and the various satellites led to important conclusions regarding radiation in low- Earth orbit. Seven oral history interviews in AIP’s Niels Bohr Library & Archives discuss Telstar and Starfish Prime.
Lest one think that satellites are now safer because we ban nuclear tests in space, the story of Telstar 401 provides a cautionary tale. Telstar 401 launched in 1993. In 1997 it was destroyed by a magnetic storm, a space weather event caused by a coronal mass ejection from the Sun. Knowledge of such events is still critical background to the design of satellites and other electrical and communications infrastructure here on Earth.