Friends,

I often see threads on this board an others, as well as social media, pondering why there is no signal from the ISS amateur radios.

In lieu of yesterday's Japan Aerospace Exploration Agency (JAXA)’s H-IIB rocket launch which will rendezvous with the ISS later this week I offer the following flight rules which were provided by Kenneth Ransom N5VHO and were reported in the ANS-313 November 9, 2014.

I believe this information explains most of the times when the amateur radios on the ISS are off. Pay attention to ISS announcements for EVAs and dockings and Robotic Arm usage and you will know, most of the time,when the radios will be off.

Sites for information include: http://www.nasa.gov/mission_pages/station/expeditions/index.html http://www.ariss.org http://http://www.issfanclub.com/

Did You Know... Current flight rules require all the ham radios to be off during an EVA. Technically, the VHF radios needs to be off for Russian EVAs and the UHF radio needs to be off for US EVAs.

For dockings and undockings, again the ISS operates under a flight rule that has the VHF/UHF radios off for Progress, Soyuz and ATV vehicle activity. Note that Cygnus, Dragon, HTV and formerly the Shuttle did not require the radios to be off.

For Ham TV, already mentioned is that it will be off for any EVA. It needs to be off for ATV (the last one November) docking and undocking. It also has to be off when the Robotics arm is in close proximity.

73,

EMike

E. Michael McCardel, KC8YLD V.P. for Educational Relations, AMSAT-NA

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