Voyager 1 is 24 billion kilometers from Earth.
It communicates with us using a 23-watt transmitter.
Less than a refrigerator light bulb.
The signal takes 22 hours to reach us, traveling at the speed of light.
By the time it arrives, it's 20 billion times weaker than the power of a digital watch battery.
NASA's Deep Space Network picks it up using 70-meter dish antennas cooled to near absolute zero to reduce electronic noise.
The engineering required to hear a 23-watt signal from 24 billion km away is arguably more impressive than the spacecraft itself.
Launched 1977.
Still transmitting.
Still being heard.
We built something that works perfectly, 47 years later, in conditions no one has ever tested in.
That's what engineering for the long term looks like.