Back to Normal—For a Time
For more than a month Telstar I behaved as it should, and our communications experiments, including television broadcasts, were resumed on January 3rd. During this time we used both normal commands and our special notched-pulse modified commands. Whenever normal commands became intermittent we used the modified commands to disconnect the battery for several eclipses.
Our good fortune, however, did not last. Continued exposure to radiation apparently led to further damage to Telstar I’s transistors. By February 14th, disconnecting the storage battery no longer returned the decoder to normal, and we could operate only with our modified commands. And, on the 21st, the satellite apparently misinterpreted a command, disconnected its storage battery, and went silent. Since then, none of our modified commands has been able to bring back its voice. There is still a possibility that Telstar I may recover if it remains out of the high-radiation part of space for a long enough period—but as time goes by this appears less likely.
However, our work was not in vain. Because we pinpointed the effects of radiation on the transistors in Telstar I, this problem was counteracted on the Telstar II satellite launched on May 7, 1963 (see [page 31]). To avoid the worst of the radiation effects, the second Telstar is in a considerably larger orbit, which causes it to spend less time in the heaviest high-energy Van Allen belt regions. It carries new radiation detectors with much greater measuring capacity. And in one of Telstar II’s command decoders we are using a new type of transistor, which we hope will not be affected nearly as much by radiation as were the ones in Telstar I’s ill-fated decoders.
E. Jared Reid was born in Hartford, Connecticut, and received a B.S. from Trinity College in 1956, a B.E.E. from Rensselaer Polytechnic Institute in 1957, and an M.E.E. from New York University in 1959. He joined Bell Telephone Laboratories in 1957, and has worked on the design and testing of the Time Assignment Speech Interpolation (TASI) system for the transatlantic cable, as well as on transistor circuits for the Telstar satellite.