Data downlink from Voyager 2 lost due to a pointing error on its antenna: https://blogs.nasa.gov/sunspot/2023/07/28/mission-update-voyager-2-communications-pause/
Although if I understand this correctly, the carrier is still detectable - it's just faint enough that the modulation isn't.
The spacecraft is expected to automatically repoint in mid-October.
Voyager 2 was able to receive the "repoint now" command.
QT @canberradsn
2023 August 4
Two-way communications have been restored with #Voyager2
The good news was received through our 70-metre antenna dish, Deep Space Station 43 at 2:29pm AEST, 4th August. #DSS43
Attached: 1 image How can Voyager 2 decode a signal when its antenna is mispointed by 2°? The graphic below shows the "antenna pattern" of the Voyager antenna. Most of the downlink energy is located in the narrow main lobe, but there is some energy in the side lobes too. The graphic shows 2 such sidelobes. The uplink signal strength has similar but wider lobes, so it is possible for V2 to decode a high power signal from the DSN at a 2° offset. Here's hoping that it does 🤞 https://descanso.jpl.nasa.gov/DPSummary/Descanso4--Voyager_new.pdf #Voyager 2/n
@michael_w_busch @AkaSci ok here's my q: wouldn't light be more efficient? or would it get too scattered by spacedust? does the sun put out more light than radio, to swamp a light signal?
sure, light would suck to use when its cloudy.
@barrygoldman1 @AkaSci Optical communication with spacecraft can be more efficient, but it runs into quantum mechanical limits: you need to have several photons per bit. And it doesn't work when it is cloudy.
Also, the Voyager spacecraft were built well before high bandwidth optical communication with spacecraft existed. It is only now being demonstrated over large distances: https://www.nasa.gov/mission_pages/tdm/dsoc/index.html
Michael Busch
Barry Goldman
AkaSci 🛰️