During Telstar I’s first two months in orbit, the only indication of
trouble cropped up in one of the command operations. Telemetry told us
that the satellite was no longer executing the T2 command. This meant
that we could not temporarily disconnect command chain No. 1 to check
the performance of chain No. 2. Then, a short while later, No. 2 began
to give intermittent operation. Finally it failed completely. At the
time, we didn’t know why this had happened, but, since the satellite’s
other command chain still seemed to be operating normally, we were not
very worried.
However, in the middle of November 1962 command chain No. 1 also began
to be intermittent. We would send a command but get no response from the
satellite; only after we repeated it a few times would the satellite
finally do what it had been told to do. Now there was something to be
concerned about. And, if chain No. 1 should fail, we had to make sure
that Telstar would be left in a favorable operating condition. We didn’t
want the satellite’s communications equipment to be left on without our
being able to turn it off—this would keep a continuous drain on the
power supply.
As we feared it would, the other command circuit went out of commission
on November 23rd. However, when this happened, the communications
circuits had been turned off, although the command chains themselves and
the telemetry remained on. This meant that we could still try to send
commands, the condition of the satellite could still be monitored by
telemetry, and the solar cells could still supply useful power. But,
since we could not turn the communications equipment on, Telstar I could
no longer be used for transatlantic television or any of the experiments
we had been carrying on successfully since July.