EMDRC High Altitude Balloon Launch – Feb 2023 Launch Report

Another great community STEM experiment comes to an end – WOW!!!! That was a just totally amazing outdoor STEM adventure. It wouldn’t be fair for me to say something like that unless i had experienced it myself, but now having experienced how cool an outdoor STEM activity like HAB (High Altitude Ballooning) can be, i have to say……it’s possibly one of the best hobbies i have had the privilege to dabble with over the years. Its also going to be a while before the adrenalin levels come down across the group :), this one sure gives us all a real high. The last launch literally kept us all on our toes from start to the end. High Altitude Ballooning definitely has to be one of the few outdoor STEM activities that has the ability to engage kids of all ages (6-66+) and bring makers, creators, tinkerers, science enthusiasts, and their families together.

Thank you to everyone who helped make the Feb 2023 High Altitude Balloon launch a massive success. A big thanks to the EMDRC committee including Martin VK3TMP, John VK3PZ, Luke VK3UKW, Brad VK3BKQ and Andrew VK3BQ for their ongoing support. A massive thanks to the entire launch team including everyone who helped with tracking and recovery of the payload. It’s humbling to be part of an initiative supported by such a warm bunch of individuals all passionate about STEM and High Altitude Ballooning.

The EMDRC launch team included –

1. Payload & Electronics – Trystan, Luke VK3UKW
2. Balloon Management Team – Greg, Chris VK3PLS, Nathan VK3DNS, Toby VK3TOS, Rory VK3ASY
3. Launch Control – Brad VK3BKQ with the support of Ryan (VK3InTheMaking) and Andrew VK3BQ
4. Logistics & Modelling – Trevor VK3TWC
5. Barbecue & Facilities Management – Tom VK3FTOM
6. Photography – VK3EEK, VK3BQ

The launch and recovery was an absolutely amazing experience. Recovery was a lot tougher than expected, if you are interested in learning more then please read the “How Things Unfolded” section for more details. We ended with a celebration at the local pub before heading back home. Thanks to everyone who helped track the payload from their launch cars, houses, mountain tops, etc. We really appreciate the effort you put into testing your equipment out, getting everything setup and then helping us track the balloon on launch day. We couldn’t have done it without all of you.

Preparing for launch – We arrived at the launch site at ~0830 Hrs on the 19th of February 2023 and started setting things up. Tom VK3FTOM was responsible for the barbecue and cooking up the snags for the launch team. While Tom VK3FTOM was cooking up snags while the rest of the team including Andrew VK3BQ, Brad VK3BKQ, Ryan (VK3InTheMaking), Nathan VK3DNS, Toby VK3TOS, Christine VK3EEK, Chris VK3PLS, Trystan, Greg started setting up and preparing for the launch. A big thank you to Tom VK3FTOM for offering to support the EMDRC High Altitude Balloon team with his culinary skills, join us for the chase thereafter.

Trystan was in-charge of the payload for the launch and was focused on getting the payload i.e. Raspberry Pi Zero with Camera, GPS, LoRA board, batteries including the RS 41 RadioSonde (Re-Programmed with the HORUS 4FSK binary) up and running. Trystan was pretty efficient and got everything running within the initial 20 minutes of setting up onsite. However soon after, we ran into some issues with the payload and seem to lose contact with the WENET payload (Raspberry Pi Zero with LoRA, Pi Camera, GPS, etc.) while still on the ground. This was quickly fixed by rebooting the Raspberry Pi, however Trystan suspected that keeping the payload on the field had caused the antenna to bend (the antenna is at the bottom of the payload) and had possibly destroyed the antenna. We hoped that this wasn’t the issue, that the antenna wasn’t completely destroyed and that things would right itself from there on. However that was wishful thinking, read on to find out how things panned out.

Greg, Nathan VK3DNS, Toby VK3TOS, Ryan, Chris VK3PLS, Brad VK3VKQ worked together to inflate the balloon and ready us for launch. 30 minutes from start we had the balloon inflated and both the payloads i.e. RS 41 (Re-programmed RadioSonde) and the Raspberry Pi Zero with Camera, GPS, etc., ready to go. Brad VK3BKQ was playing the role of Launch Command on the day and confirmed that the payloads looked good, that we were ready to launch. Andrew VK3BKQ had his drone up in the air and was taking some really cool pictures and videos while Christine VK3EEK was using a professional DSLR camera to grab some fantastic high resolution pictures. It was humbling to see everyone come together, working as a team to launch the balloon.

We launched around 1030 Hrs AEDT, packed up and started chasing the balloon. The flight path modelling right upto the launch had confirmed that we were in a very tight situation. We were either going to land within the Avoca state forest on the left or within the Glenmoran state forest on the right. Given the wind speeds, weather conditions for the day i had to to tweak the launch parameters so we could get the balloon and payload to land in between those two state forests. Check out the launch variables in the next section if you are keen to understand what launch variables we ended up choosing. The decision to go with a particular amount of helium gas, a particular size of parachute, a particular size of balloon, etc. was based on the flight path prediction based on the data available at the time of launch and the hardware i.e. balloons, parachutes, amount of helium, etc. available to us on the day.

We had to be absolutely on the ball, make sure we had done our math right else we were going to have the payload land within the state forest and that would make it very hard for us to retrieve our payload and the parachute.

Chase and recovery – It was going to be a short flight due to the low wind speed forecast for the day. The entire entourage got into their cars, turned on their tracking computers (Raspberry Pi’s with an RTL-SDR and antennas on the roof) so that they could track the High Altitude Balloon and payload overhead. The entire launch team then drove to the forecasting landing spot and stationed themselves close by. We had aimed for a descent of 2.77 m/s through a combination of the payload size, parachute size (42inch spherachute) however it was soon evident that during descent the speed of the payload was still way higher at ~5-6m/s which is much higher than what we had modeled for. We were very surprised with that behavior and didn’t know then what had happened at the time. It was critical that the payload attain the ~2.77 m/s descent to be able to make it over the Avoca state forest and land just before the Glenmoran state forest. However that was not to be. The payload landed at the periphery of the Avoca state forest maintaining a much higher descent rate than what we had modeled for.

We drove as close as possible to the landing site and realized that the payload had indeed landed at the periphery of the Avoca state forest. Andrew VK3BQ reviewed the local maps, suggested that we drive up to one of the farms nearby and request the farm owner for his/her permission to enter their plot, using the fire access path to head into the state forest and recover the payload. We entered the property and met up with Peter Howell who owned ~3000 Hectares of land on the boundary of the Avoca state forest. Peter heard us out and then suggested that we drive with him in his 4WD along the ridge of the mountains which bordered his property to get close to the landing site. So Peter along with a bunch of HAB’ers drove out in his 4WD while Trevor VK3TWC and Luke VK3UKW drove out in a 4WD buggy following Peter along the mountain ridge. The climbs were really steep, some places ~50-60 Degrees and mountain terrain all over. However Peter was really steady all through in his Nissan 4WD while Luke VK3UKW held the wheel steady in our 4WD buggy and we eventually made it to the outskirts of the state forest, close to the landing spot.

Andrew VK3BKQ and some of the others spotted the parachute in one of the tree approximately 100 yards away however we had to go down a ravine to get to the balloon. Tom VK3FTOM, Toby VK3TOS, Nathan VK3DNS, Greg and Rory VK3ASY went down the ravine in an attempt to fetch the balloon. 20 minutes later we heard shouts of joy confirming that they had indeed found the payload. The group then made their way back up the mountain to where rest of the team was stationed along with their 4WD vehicles. Pictures were taken along with Peter before we headed back down the mountain ridge, this time following a shorter path back to Peter’s farm property. I was just worried for the team, was hoping that we didn’t end up with any injuries, we came away with some minor scratches. Another lesson learned is to scrap a launch if we end up with similar weather conditions and flight path predictions. I want my people to be safe, that’s more important to me than any science experiment in the world, so this is going down in our lessons learned document and into the checklist as well feeding into our Go/No-Go decision.

After retrieving the balloon, getting some of the local HAB experts (Mark VK5QI), etc. involved it was apparent what had happened and why the descent rate was higher than what we had modeled for. We had used a longer than required i.e. ~2+m of line between the balloon and the parachute. This meant that when the balloon burst, the explosion cause what was remaining of the balloon to entangle itself around the line just below it (and above the parachute). This was the reason the 42 inch Spherachute hadn’t fully deployed and we weren’t seeing the expected descent profile modeled for a descent rate of 2.77m/s, more like a descent profile for a smaller parachute i.e. 24 inch Spherachute. Another lesson learned…be careful with the amount of line between the balloon and the parachute.

Launch timeline In Pictures – Here’s a timeline view of the entire launch pictorially represented.

Pictures captured by the on-board Raspberry Pi Camera – Here’s some of the pictures taken by on the Raspberry Pi Camera on board the main payload. The streaming of images over WENET stopped soon after launch, this was due to snapping of the main antenna due to the payload being kept on the ground with the antenna at the bottom all squashed up. Some good lessons learned on this front.

Key launch variables include – Here’s a summary of the critical launch variables.

1. Scientific balloon – Hwoyee 600
2. Parachute – 24 inch spherachute
3. Gas – Pure helium gas
4. Weight of payload – 380 gm
   1. Pi Zero W with camera, LoRA board and batteries – 240gm
   2. Reprogrammed RS 41 radio sonde with batteries – 80gm
   3. 42 inch Spherachute – 60gm
   4. Data Logger1 (Pi Pico with PiicoDev BME280) – 225g
   5. Data Logger2 (Pi Pico with PiicoDev BME280) – 125g
5. Ascent rate – 6.5 m/s (targeted)
6. Descent rate – 2.77 m/s (targeted)
7. Burst Altitude – 29895 Km
8. Payload – Styrofoam box with the following :
   1. Primary Payload –
      • Raspberry Pi Zero with a camera, GPS
      • Lora board connected to the Pi Zero W for purposes of streaming images (over Wenet)
      • 1/4th Ground plane antenna
   2. Secondary Payload –
      • Re-flashed Bureau of Meteorology Radiosonde (RS41) with the HORUS binary
      • 1 x Data Logger Modules : Raspberry Pi Pico with PiicoDev BME280 sensors
9. Frequencies in use –
   1. Wenet (SSTV image transmission) frequency : 441.200 Mhz
   2. HORUS (RS 41) frequency : 434.200 Mhz
   3. 2m Repeater Ararat for local comms (91.5Mhz CTCSS, +600 Offset)– 147.100 Mhz
10. Frequencies for monitoring (NO TRANSMISSION ALLOWED)-
    1. YARA (Ararat Aerodrome) CTAF for monitoring prior to release of balloon – 126.7 Mhz
    2. YARA (Ararat Aerodrome) Melbourne FSS (Melbourne Center) for monitoring prior to release of balloon – 126.8 Mhz

Feb 2023 High Altitude Balloon Launch Technical Report – If you are looking for details of the metrics captured during the launch i.e. temperature, pressure, humidity, ascent rate, descent rate, altitude, etc. then head over to the following link and access the report – <Access Detailed Technical Report Here>

Chat with Discord – We keep in touch through discord (Chat Server).

1. Join us at our “Make, Innovate, Create” Discord Server.
2. Joining us on discord doesn’t cost you anything, it’s absolutely FREE to join.
3. Please read the #rules channel to understand the guardrails we have put in place to make sure discord remains a safe place for everyone.
4. And here is the URL for getting onto discord – https://discord.gg/4FkrKJeNt5

Be part of an exciting journey : Everyone is invited to join the MRPMG & EMDRC High Altitude Balloon group and participate in our next High Altitude Balloon Launch. There’s a lot of interesting design, build, test activities to be performed before the launch. If you have the interest, keen to pick up skills in electronics, designing / testing / debugging, high altitude balloon launch and recovery, keen to learn more about Software Defined Radios, or gain hands on experience setting up and launching custom Raspberry Pi payloads into the stratosphere then join us on discord and drop us a line.

You also have an amazing opportunity so help shape the next generation High Altitude Balloon payload, test the payload to get it ready for the next launch, be part of the launch team helping launch the balloon and finally join everyone for the chase, payload recovery soon after. However, If you would rather stay home or rather grab a coffee and track the payload remotely then that’s great too. Here’s links to the software you need to track the High Altitude Balloon and payload we are launching.

1. Project HORUS Chasemapper – Plot your position on a map relative to the balloon using a Raspberry Pi and GPS
2. Project Horus horusdemodlib – Plot a reprogrammed radiosonde used as a payload for Amateur High Altitude Balloons
3. Project HORUS Horusgui – Windows software to track a reprogrammed radiosonde used as a payload for Amateur High Altitude Balloons
4. All of the images are broadcasted in real-time from the balloon (over WENET) – https://ssdv.habhub.org/
5. Link to track the Horus payload in real time – Sondehub

Read more about High Altitude Ballooning and get started with your own High Altitude Balloon journey at https://hack2.live/high-altitude-ballooning/. Drop us a note at trevor at hack2 dot live if you have any questions, suggestions or comments.