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1. AkaSci 🛰️ (akasci@fosstodon.org)'s status on Friday, 04-Aug-2023 19:18:32 UTC AkaSci 🛰️

   Update on Voyager 2, which lost contact with earth on July 21 due a mispointed antenna.

   Voyager 2 is programmed to reset its orientation Oct 15; meanwhile, NASA is trying to make contact.

   On Jul 31, the DSN station in Canberra picked up a faint signal, not strong enough to decode. It shows that V2 is healthy and calling home periodically as programmed.

   On Aug 3, some commands were blasted out from Canberra (perhaps at higher power) in the hope that, V2 can decode it and repoint.

   #Voyager
   1/n

   • AkaSci 🛰️ (akasci@fosstodon.org)'s status on Friday, 04-Aug-2023 19:18:29 UTC AkaSci 🛰️

     in reply to

     Hallelujah. It Worked!
     NASA has reestablished full communications with Voyager 2!!!

     The commands sent from DSN Canberra on Aug 3 were received by Voyager 2 and it is repointed.

     At 12:29 a.m. EDT on Aug. 4, 2023, science and telemetry data started to be received from V2.

     https://blogs.nasa.gov/sunspot/2023/07/28/mission-update-voyager-2-communications-pause/
     #Voyager
     5/n

   • AkaSci 🛰️ (akasci@fosstodon.org)'s status on Friday, 04-Aug-2023 19:18:30 UTC AkaSci 🛰️

     in reply to

     To make matters worse, 1 of 2 receivers on Voyager 2 is healthy, but a fault prevents it from accurately tracking the receive signal. Signal frequency varies due to the rotation of the earth (doppler) and receiver temperature. V1 can track signals that are off by +-100 KHz, but V2 can only handle +-100 Hz. For V2, tx from earth is pre-compensated in freq, taking earth rotation and V2 temp. into account.

     W/o temp. info, they might be trying multiple values.

     https://descanso.jpl.nasa.gov/DPSummary/Descanso4--Voyager_new.pdf
     #Voyager
     3/n

   • AkaSci 🛰️ (akasci@fosstodon.org)'s status on Friday, 04-Aug-2023 19:18:30 UTC AkaSci 🛰️

     in reply to

     There is some more info on Voyager 2 in this earlier thread.
     https://fosstodon.org/@AkaSci/110792770324764839
     #Voyager
     4/n

     Ricardo repeated this.
   • AkaSci 🛰️ (akasci@fosstodon.org)'s status on Friday, 04-Aug-2023 19:18:31 UTC AkaSci 🛰️

     in reply to

     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