Hi Juno After-Action Report

As I write this, the Juno spacecraft has completed its slingshot maneuver around Earth, having stolen a bit of Earth’s rotation energy. and is now on its way out to Jupiter. A bit before the designated 1800 UTC start time for the event, I was able to set up my Icom IC-718 at the appointed frequency of 28.324 MHz with an output power of approximately 60 watts CW.

I executed the hijuno.py script via SSH (as mentioned in my last post) a few minutes shy of 1800, turned on my handheld scanner so I could monitor the transmit frequency, and waited for the show to start. I also checked a few WebSDR receivers to see if I could detect how many hams were participating in the Hi Juno event.

Hi Juno Website
Hi Juno Website

The transmitter started up, but immediately I could see that it wasn’t in sync with other stations that I could hear and see on the receiver. My shack PC is running Ubuntu 13.04 and it set up to automatically set its clock via NTP, but obviously it was off by quite a bit. So I had to duck into the shack quickly to manually update NTP, then come back to my laptop to restart hijuno.py via SSH. This time, I could see by following along with the interactive Hi Juno website and listening to my transmit monitor, that my timing was correct. As you can see above, the website had a nice graphical display of when to key up and key down for those doing this manually. That little yellow triangle at the bottom of the screen moved from left to right to indicate the current position within the transmit timing window.

W5ZA WebSDR
W5ZA WebSDR

At this point, satisfied that the Python script seemed to be working, I went back to WebSDR for a listen. The W5ZA 10 meter beacon receiver in Shreveport, Louisiana seemed to be a great choice for monitoring all the Hi Juno signals out there, probably because it was still in daytime, as opposed to the European receivers, which seemed to be showing nothing. Normally this would be considered bad, but I have to think in this case it was a good thing, since the ionosphere was probably not reflecting 10 meter signals back to Earth in this part of the world, and they were free to make it to Juno. To the left, you can see a screen capture of the W5ZA WebSDR just after a Hi Juno keydown period.

The rest of the event was fairly…uneventful. The Python code worked perfectly and stopped transmitting at the right time. It was fun chatting on Twitter with other hams who were also participating in the event. Based on watching the WebSDR waterfall and checking Twitter search, it seemed like there were quite a bit of us taking part in the event. I have no idea, how long it will take for us to hear back from the investigators whether this worked or not, but I hope it’s fairly soon. I’m definitely looking forward to getting a QSL. My first one from an interplanetary spacecraft. I also have to say that the Hi Juno website worked wonderfully during the event with its simple and clear graphic instructing you when to transmit, and showing you transmit window. if we ever get more opportunities to participate in experiments like this in the ham community, it should be a model on how to run things. Even though we didn’t get any immediate gratification, it was a fun event and I hope that NASA/JPL reaches out to us again in the future.

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