In the midst of a global pandemic, classroom learning continues. This is a story about a high school physics class continuing to operate and expand its horizons through exposure to the magic of amateur radio satellites – even while taking on the challenges of social distancing.
The Ask: Please Help Us Contact the ISS
About two weeks ago, one of my neighbors asked me if I could help some students contact the International Space Station (ISS) via ham radio as part of a Physics project for school. I thought, “Wow! What a great opportunity. It’s a big goal, but, if possible, I’d love to help them make this happen.”
I met with the three high school freshman immediately via Zoom to hear more about what they wanted to do. They had just completed a Physics unit on orbital mechanics and their final assignment was to find a practical way to experience what they had learned. But, when they told me that they needed to get the project done in about five days, I gently explained the issues of worldwide demand, limited availability of astronaut time and complexity in setting up a school contact with the ISS via amateur radio. They quickly understood that while possible, making one happen in just a few days would be impractical. They were slightly disappointed.
How Else Might We Satisfy the Learning Objective?
There had to be a way to help the students experience the phenomenon of orbital motion. If we focused on the ISS, we could hope for a pass over our area and actually see the satellite as it crosses the night sky. But, would there be a good enough pass over the next few days? Would weather cooperate? How could we arrange this while still observing social distancing? Too many what-if’s. We needed a different approach.
So, I offered them the opportunity to learn about and experience communications using amateur radio satellites – an alternative that would allow them to achieve almost everything they wanted to accomplish. When they heard the idea, their enthusiasm rebounded immediately.
A Quick Ramp-Up and an Achievable Goal
So, we started to get ourselves educated on amateur radio satellites. I directed them to some helpful web resources:
- Amateur Radio on the International Space Station (ARISS)
- Amateur Radio Satellite Corporation (AMSAT)
- National Association for Amateur Radio (ARRL)
Meanwhile, my home satellite station hasn’t been running for a while. Two years ago, while I was setting up computer control of my Az-El rotor, the rotor failed – permanently. That, unfortunately, sidelined the project. So, I had to come up with something quickly to satisfy the needs of this new project. I dug out my trusty Yaesu FT-847 and connected it to SatPC32 pass prediction software running on a laptop and a dual-band vertical at 20 feet, just to see if I could hear any of the amateur satellites. Good news! They weren’t pinning the S-meter, but I was hearing several of the active satellites – SO-50, AO-73 (FUNcube-1) and the XW-2 satellites. Beacons and some QSOs were audible. Things seemed better on 2m downlink than 70cm.
I got back to the students and let them know that it would be possible to hear these satellites. Then we got to talking about their learning objectives. The goal was to get some hands-on experience with orbital motion. How could we accomplish that with an invisible amateur radio satellite?
First, we walked through the SATPC32 pass prediction software. We looked at the views of earth and the paths the satellites were taking as they orbited the globe. We discussed the concept of a visibility footprint. Then, an idea came to mind. I asked the girls if they had learned about the Doppler Effect in their Physics class. It turns out that they had been exposed to the concept earlier in the year – and the examples they studied were all in the audio realm. When I told them that the radio transmissions to and from a satellite would be affected by Doppler, they were interested. So, we set a goal to observe Doppler as we listened to transmissions from an amateur radio satellite.
Getting it Done in this Time of Pandemic
Video conferencing has truly come of age in recent months. Previously used primarily by businesses and tech-savvy individuals, virtual meeting technology – driven by pandemic restrictions – has become the communication tool of choice for all of us – from the most to the least technically-oriented. And, the Zoom service has emerged as one of the most effective implementations for consumer use. The students were well-versed in the use of Zoom . . . and virtual conferencing and collaboration technology has been my business for 30 years . . . so it was easy to jump right into using Zoom meetings to keep our project on track.
I provided several references to help them get a basic understanding of Doppler in the context of satellite-based communication systems.
- Satellite tracking and prediction software with Doppler compensation – SatPC32
- Doppler effect on satellite communication
- Calculating Doppler shift for satellites – lots of math!
After reviewing the reference material and doing some research on their own, we got together on Zoom to discuss and observe the Doppler shift, in a real satellite communication system.
We listened to the XW-2A satellite as it went overhead. The beacon shifted frequency, as we predicted.
Bonus . . . A Voice Contact Via the Satellite!
As the XW-2A satellite continued its journey across the sky, we noted that the beacon was quite strong. We wondered if we would be able to hear stations making contact through the satellite. As we scanned the satellite downlink frequency range, we found a station making a general call – looking for a contact. We replied to his call . . . and he responded!
Our contact with Don, callsign AK2S, lasted only about 2 minutes, as the satellite was rapidly nearing the horizon. But, it was quite a success – more than we had expected to be able to accomplish with the limited time and antenna system available to us.
Lessons and Retrospective
- Learning Objective: Accomplished . . . and More
We were very pleased to have observed the Doppler Effect as the orbiting XW-2A satellite passed overhead. It gave the students a glimpse into the behavior of an object orbiting the earth at high speed. The students also had the opportunity to experience a two-way satellite contact.
- Even a Global Pandemic Can’t Stop Us
The restrictions imposed on the students by the Covid-19 pandemic were not enough to stop them. In fact, these unusual circumstances gave them the incentive they needed to go beyond the classroom and seek out an interesting new experience. The availability of easy-to-use. low-cost video conferencing made it possible to achieve the learning objectives while carefully observing the social distancing required in today’s world.
- A Brief Introduction to Amateur Radio
The students took the initiative to reach out in an effort to learn about ham radio and how it is connected to space and satellites. They came away with new knowledge about an avocation enjoyed by hundreds of thousands of individuals in the US and millions around the world.
- Impact on Others
After the satellite contact with Don AK2S, I reached out to him by email to tell him ‘the rest of the story’. We spoke for quite some time. I was pleasantly surprised to learn that Don spent his career designing commercial communication satellites, and now works with AMSAT on a variety of amateur satellite projects. Don is a big believer in STEM as an important element in the future of amateur radio. He was very pleased to be a part of this learning experience. As many hams do, Don passed along QSL cards for each of the students.