The Forgotten Frequency

Two physicists at Johns Hopkins Applied Physics Laboratory were listening to static. It was the fourth of October, nineteen fifty-seven. Sputnik had been in orbit for less than a day. The satellite was not a mystery — the Soviets had announced its launch frequency in advance, a matter of public record. What it was doing up there, exactly, in terms of orbital mechanics, was a different question entirely. William Guier and George Weiffenbach had a receiver in the laboratory that could pick up the signal. They pulled up chairs and started recording. The Soviet government had published the transmission frequency before the launch. But American tracking stations, working from earlier Soviet communications that turned out to be preliminary or misleading, had initially been tuned slightly off. Some stations missed the signal entirely in those first hours. Guier and Weiffenbach found it. The tone was clean — a steady radio pulse, repeating at regular intervals — and as Sputnik arced across the sky overhead, they noticed something that would have been easy to overlook: the pitch was shifting.