...so I'm reading up on telemetry support via Deep Space Network (DSN) and I'm wondering if scientists expect to lose contact with the spacecraft at a certain point.

I don't have an estimated date at hand, but the most likely cause
of eventual loss of contact is the declining ability of the RTGs
(radioisotope thermoelectric generators) to convert heat from the
plutonium heat sources into electric current. The converters slowly
degrade over the years (because of the radiation, I think), and
eventually they won't put out enough voltage to power the radio
transmitters. The plutonium itself would last a few hundred years.

-- Jeff, in Minneapolis

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http://www.FreeMars.org/jeff/

"I find astronomy very interesting, but I wouldn't if I thought we
were just going to sit here and look." -- "Van Rijn"

"The other planets? Well, they just happen to be there, but the
point of rockets is to explore them!" -- Kai Yeves

Specifically, the RTGs have an 88 year half-life. But that doesn't mean that all systems in Voyager will run at half speed in 88 years. Some systems require a certain threshold of power to keep operating.

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Forming opinions as we speak

Thanks.

I think the consensus is that the Voyagers will be dead in the water (power-wise) by 2020, when Voyager 1 and Voyager 2 will be about 148 and 125 AUs from the Sun, respectively.

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--Kung Pow!

Here are the specifics.

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DTR is the Digital Tape Recorder, for anyone wondering about that unexplained acronym.

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The exciting part is that both probes will likely pass beyond the heliopause -- and therefore out into interstellar space -- before their radios will stop operating. Within our lifetimes, we'll be receiving radio signals from outside the solar system! Granted, they'll be from man-made craft rather than alien intelligences, but even still how cool is that? Especially when you consider that the Voyagers will be the first craft from Earth to encounter matter that came from another star other than the Sun! The whole enterprise is very exciting, both scientifically and as a landmark of human achievement.

<joke> I cannot believe that NASA decided not to use one of the many free energy machines to power these probes indefinitely. Obviously they are being coerced by aliens to "engineer' these probes to fail before they can get too far from earth and discover the truth.</joke>

Any plans to launch new probes with better power cells?

There are currently no plans for any "interstellar" missions unless you count the Pluto missions New Horizons, which will be leaving the solar system like the Voyagers but is similarly powered (and less powered, if anything).

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Maybe we'll live long enough to see the Interstellar Probe come off paper.

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"I must find if I too if I possess this special skill. Remember, do not stop until I give you the signal or dramatically throw you to the ground and request a towel."

--Kung Pow!

Hmmm... the above answers have all focussed on the Voyager probes themselves.

My own understanding of the situation is that the Deep Space Network (DSN), i.e. the radio antennae that receive signals from distant spacecraft, is the limiting factor. We are sending out probes that are able to collect more data than ever before (such as the latest to Mars, the Mars Reconnaissance Orbiter, see here http://marsprogram.jpl.nasa.gov/mro/index.html). The data collected by these probes must be sent back and recveived somehow, and both time and bandwidth on the DSN are being stretched.

I think what is most likely is that we will stop listening to V'gers 1 and 2 before their signals are too faint to detect.

Unless we upgrade the DSN very soon, and by a sufficiently large margin to give it plenty of space to grow.

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The great violinist was bowing;
But how is the sage
To tell, from the page:
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