There is a communication pause with Voyager 2 since July 21, the antenna points 2 degrees away from Earth. A series of planned commands sent to NASA’s Voyager 2 inadvertently changed the antenna alignment.

Source Mission Update: Voyager 2 Communications Pause

How large is the beam width compared to the 2 degrees miss-alignment?


1 Answer 1


According to Wikipedia https://en.wikipedia.org/wiki/Parabolic_antenna the half-power beam width for a 3.7m diameter antennae (like Voyager 2) with X-band transmission at 3.6cm would be 0.60 degrees.

Voyager 2 also has S-band communications at 13cm which would have a half-power beam width of 2.5 degrees using the same parabolic reflector.

  • 2
    $\begingroup$ But is S-band downlink still possible over the huge distance from Voyager 2 to Earth? Antenna gain 36 dB for S-band is much smaller than 48 dB for X-band. S-band seems to be used only after launch but not nowadays. $\endgroup$
    – Uwe
    Jul 31, 2023 at 16:16
  • 2
    $\begingroup$ Sounds like a new question. @Roger Wood is very knowledgeable on Voyager communications. $\endgroup$
    – Woody
    Jul 31, 2023 at 17:23
  • $\begingroup$ Doesn't Voyager only use S-band for uplink? X-Band is for downlink and irrelevant here, because earth needs to upload the corrected navigation commands, not download anything. $\endgroup$
    – Rainer P.
    Aug 7, 2023 at 11:35

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