Eli5: Are satellites really ‘beeping’ and why?
In: Engineering
The first satellite launch, Sputnik, had a simple radio circuit and battery that would send out regular beeps on the radio if you tuned inn to it. This was to prove that they had actually launched a satellite into orbit. The implecation being that they would therefore also be able to launch any nuclear weapon to anywhere in the world. The sounds from Sputnik is the classical satellite beeping sound you hear in movies and tv shows and have become a classic trope.
However similar radio transmissions continued to be used by sattelites but now modulated with data collected by the satellites instruments. So they would not sound like a clear beep but rather like random noise like from a classical modem. You can hear some of this in for example recordings of 60s space flights. Not all recordings include them but those that do will have the sound interupted by what sounds like random static but they are at regular intervals, just like the beeping Sputnik. If you were to analyze this static you would be able to extract telematry data from it.
Sattelites do still transmit telematry data although with modern techniques they use different modulations and do it at different intervals then the early satellites. And they are able to be encrypted and digitally signed so that others can not interfering with their signals.
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