Voyager still actually gets up to a whopping 1.4 kbps downlink! (but only 16 bps uplink)

https://voyager.jpl.nasa.gov/mission/spacecraft/

That's a bit confusing; shouldn't it be the other way around? Because they're using the same antennas in both directions, but the power budget on the Earth-transmitting side is much higher.

(Asked in the spirit of curiosity; I'm ignorant of radio physics).

I'm assuming that our ability to computationally aid / resolve signal is far higher than voyager's.

That's a factor, but I think it's more that there was never a need for large data uplinks to Voyager, while they needed to downlink large amounts of science data.

The uplink and downlink are in different frequency bands, S-band (2-4ghz) for uplink and X-band (8-12ghz) for downlink and have different amounts of radio frequency bandwidth allocated.

Additionally, Voyager's High-gain antenna has a much narrower beamwidth in X-band at 0.5°, compared to 2.3° for S-band, though I have no idea if that's a factor.

Plus receiver size.

It’s mainly this and it’s normal for spacecraft (especially in deep space) to have orders of magnitude more datarate on downlink.

There are a couple of factors at play here.

The first is that the downlink is at a higher frequency (X-band, 8.4 GHz) so there is more available bandwidth and the beamwidth of the antenna is tighter at a higher frequency (i.e. the power is more focused). The uplink is at 2.3 GHz, but part of the advantage of the larger beamwidth is that you are able to command the spacecraft if there is an anomaly and it is the high gain antenna is more offpointed. There is also a low gain omnidirectional S-band antenna in case it is really offpointed.

Although the signals both come through the high gain antenna there are two different feeds for the X-band and S-band. If you take a look at the picture of the antenna on Wikipedia [0] you can see the X-band feed is the prime focus behind the subreflector. The S-band feed is mounted on the subreflector so its not seeing the optimally focused signal (which the lower frequencies are less sensitive to this overall loss of focus for the reasons above).

Generally a lot of spacecraft are designed with a much higher downlink to get science data down, but you only need a pretty small link to get commands up to the spacecraft.

[0] https://en.wikipedia.org/wiki/Voyager_1#Communication_system

well, problem solved then! no need to update cec anymore

Realtime status of the Deep Space Network:

https://eyes.nasa.gov/dsn/dsn.html

I guess this would be one of those cases where you'd want to use the most aggressive compression algorithms in the history of mankind, almost regardless of compression/decompression time, because you'd definitely make overall transmission times faster.

Of course, this wouldn't help Voyager, but it would help similar modern projects, since we can throw billions more computing power at these kinds of projects, these days.