Jay: Based on these numbers, it will be a significant engineering achievement to maintain communications with the spacecraft for as long as possible, and will provide good information for later missions to similar distances.

The uplink from Earth to the Voyagers via the DSN uses 400kW-
Voy-1: 2114.6 MHz
Voy-2: 2113.3 MHz

Remember that those DSN dishes are 70 meters in diameter and have a gain of 48dbi. Not only that but they are the pioneers of weak signal processing at the receiver end.

Ancient battery tech or no, you’re mostly in a use-it-or-lose-it situation, because the radioactive material decays whether or not you’re using the electricity. Just as importantly, you can’t use up the radioactives faster to generate more electricity but a shorter lifespan.

I’d suggest that it’s more that they have a finer understanding of the decreasing, useful output of the power source than they once did.

Ray Van Dune: What I know is that before they were going to keep as many science instruments functioning for as long as possible, but that would cause power to run out by c2026. Now it appears they are going to shut down those instruments one-by-one so that they can extend the spacecraft life.

To me, this means they have shifted priority from science to engineering. Whether that shift makes sense however is another question — one that you quite correctly raise.

Thus, I am puzzled that the extension is deemed to be “… not so much to do science but to test the limits of its engineering.”

The scientific value of probing further outward seems indisputable, but I am less convinced of the value of studying the engineering limits of 47-year-old technology. Can you clarify your thinking?