Looking for the Trouble Spot
At this point a number of Bell Telephone Laboratories engineers began to analyze Telstar’s troubles. As you can imagine, we had a rather difficult problem. We obviously could neither go up and look at Telstar nor bring it down for an overhaul on the ground. We could only send different commands to the satellite and watch the telemetry data to see what, if anything, happened.
After checking the satellite’s other equipment, we were happy to find that everything except the command chains was in good condition. So we decided the trouble had to be one of five possibilities:
- excessive electronic “noise” in the satellite, which had blocked the command receivers;
- extreme temperature variations, which had caused a joint to expand, contract, and finally break;
- a loose connection;
- slow aging of an electronic component;
- deterioration of a component from excessive radiation bombardment.
We could quickly narrow this list down. Telemetry indicated that the receiver was not being blocked by noise. Reports from the temperature-measuring thermistors told us that inside the satellite the temperature was 75 degrees Fahrenheit, just as it should be. A loose connection was very unlikely, because every one had been made by expert wiremen, examined by trained inspectors, and then completely encapsulated in polyurethane foam. Aging also seemed very improbable, since all the components had been individually tested and selected for the highest reliability and longest life.