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Comment by shadowgovt | Hacker News Reader

The neat thing about the radio tech in question here is that while the signal continues to weaken, broadcast and reception tech keeps up with it. I don't know when (if) the curve runs out on that process, but we have a planet's worth of resources to bring to bear on the problem, as long as someone's willing to keep paying to upgrade the transceivers (and it's work that pays some nice side dividends in terms of being a convenient toy problem for testing new radio tech).

Since we know exactly what we're looking for and exactly where it should be, we have all kinds of neat radio tools to bring to bear on sampling a faint signal from interstellar noise.

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Right, I am not sure the limiting factor here is our ability to send or interpret the received signals. I think the limiting factor that is most impactful is the probe itself.

Eventually, its power source will die out, its components will fail, or enough cosmic rays or debris will corrupt enough of its systems it can no longer transmit.

Given those factors, I do wonder what the expected lifetime of the probe is, with the power source being the most clear "game over" line.

Good point.

It appears that both Voyagers are slated to have some experiments disabled soon (2020 and 2021) to best use remaining power from the RTGs, but since the RTGs are nuclear sources, the decay rate is independent of power draw (it's more an issue of switching off the experiments to avoid peak draw killing the ship).

Voy1's expected to lose too much wattage to turn on the radio by 2025; I can't find a quick number for Voy2.

EDIT: It appears Voy2's power package was expected to allow mission operation through 2020, so sayeth Wikipedia; no idea if that implies the radio was expected to die this year or this was the year the craft would need to be reconfigured for a scaled-back mission profile to maintain enough power for attitude control and radio transmission.

What about sending a repeater station once in a while to follow them? Or would it be inefficient compared to constantly updating radio tech here on Earth?

Received radio power decreases as the square of the distance. If the repeater started now, to be useful it would have to be similarly large to the big radio telescopes used to receive the signal. It would need to have the same speed as the probe it was following to keep up the signal. But the Voyagers each were massively accelerated by their giant planet encounters. Launching a much-more-massive repeater at much higher initial velocity than the original probes is nonsensical.

Why would it have to be massive? In space, radio dishes can be unfolded mylar.

The point is it would be massive relative to the probes, and it would also have to be moving faster than them to be useful anytime soon. And if you could launch something that massive going that fast, why bother making it a repeater. Just launch a new probe with a bigger antenna.

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