NASA hears from Voyager 1, the most distant spacecraft from Earth, after months of quiet
Launch, Sept. 5, 1977
The most distant spacecraft from Earth stopped sending back understandable data last November. Flight controllers traced the blank communication to a bad computer chip and rearranged the spacecraft's coding to work around the trouble.
…
It takes 22 1/2 hours to send a signal to Voyager 1, more than 15 billion miles (24 billion kilometers) away in interstellar space. The signal travel time is double that for a round trip.