
How did a spacecraft launched in 1977 keep transmitting from beyond the Sun’s magnetic bubble on less electrical power than a household hallway bulb?
Voyager 1 launched in 1977 and now transmits from beyond the heliopause on roughly 12 watts — about what a hallway nightlight draws. Here is how a plutonium battery, a 3.7-metre dish, and 68 kilobytes of memory keep the conversation going across 25 billion kilometres.












