Telstar Anniversary Reminds Us How Far Space Weather Has Come

Abstract

The 50th anniversary of the launch of the first active communications satellite, the Telstar satellite, was marked 10 July 2012. The successful operation of Telstar during its almost 6-month life registered several firsts, as emphasized by President John F. Kennedy in an announcement (http://m.youtube.com/watch?feature=plpp&v=lzPZoeOPCJ8) that also bore evidence of the central role played by the Cold War in U.S. foreign policy at the beginning of the space age. Although cosmic rays had been discovered about 50 years earlier and several theorists had discussed particle motion in the geomagnetic field, when John R. Pierce at Bell Laboratories proposed Telstar in 1954, he had little reason to believe that the environment around Earth was anything but benign. All prior perspectives of Earth's space environment were revolutionized by James Van Allen's discovery of stably trapped radiation in early 1958. 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 other components available at the time. In order to understand the possible effects of the newly discovered trapped radiation on the transistors, Telstar also flew with several solid-state detectors behind different entrance shields to separate electrons of different energies. At the 50th anniversary celebration at Alcatel-Lucent Bell Laboratories, the physicist responsible for these detectors, Walter Brown, presented some of his historical data showing the effects of space weather on the new (at the time) technology of communication satellites. Brown's detectors did not measure the natural radiation: On the day prior to Telstar's launch, the U.S. had conducted the Starfish Prime high-altitude (400 kilometer) nuclear test in the Pacific. This test not only produced an electromagnetic pulse that caused severe electrical grid disturbances in Hawaii but also injected electrons into the radiation belts at concentrations more than 100 times that of the natural environment. These electrons damaged Telstar's transistors, resulting in subsystem shutdowns and final spacecraft failure in mid-February 1963. The Starfish electron data obtained by Brown's detectors are referenced to this day. These data provide unique information on electron lifetimes at low Earth altitudes and represent essentially the only existent data on the results of such a human-produced event. For the celebration, Bell Labs asked that I provide an overview of the effects of space weather on communications following Brown's historical presentation. From the time of the first such effects on the electrical telegraph, to long cables, wireless, and communication satellites and navigation, Earth's space weather environment continues to define design parameters for technologies as well as possible mitigation procedures against deleterious events. Telstar's anniversary celebration provided an excellent opportunity to review how far knowledge has advanced in understanding space weather and to reflect on how critical knowledge of the space environment is for the successful design and implementation of modern technologies. Louis J. Lanzerotti is editor of Space Weather and a distinguished research professor of physics at the New Jersey Institute of Technology in Newark. He is retired from Lucent Technologies Bell Laboratories. E-mail: ljl@njit.edu.