TL;DR
On Nov. 18, a spacecraft launched in 1977 will be so far from Earth that its radio signal, moving at the speed of light, takes a full day to get home. Voyager 1 will be about 16.09 billion miles out, farther than anything people have ever built, and it is still talking: in September engineers pulled off a delicate power swap that keeps its last science instruments running longer than planned, and after a two-day silence in October its signal came back and has held since. For people, it is proof that a machine built with 1970s parts can keep working for half a century in interstellar space, and a preview of what every message to a future star probe will feel like: send a question, wait two days for the answer. Our odds that Voyager 1 is still in contact when it crosses the one-light-day mark: 95% that it works, likely by 2026. For the full odds on how long the oldest probe keeps sending science, and the timeline of the milestones still ahead, subscribe.
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