High Altitude Balloon Launch Report – 4th September 2022

The EMDRC High Altitude Balloon Launch scheduled for the 4th of September 2022 is now complete. This is the High Altitude Balloon Groups first launch and a milestone that we will all remember for years to come. This launch was made possible by the perseverance, dedication and concerted effort from individuals across multiple groups and organizations. Its impossible to name everyone here but a special thanks goes out to the following individuals and organizations who have been instrumental in helping the High Altitude Balloon group to get to this point –

1. Chris Gommersall
2. Harsh Talpada
3. Greg Boyles
4. Andrew B
5. Trystan CJ
6. Rohan VK3TRO
7. Rory VK3ASY
8. Mark VK5QI
9. John VK3PZ
10. Brad VK3BKQ
11. Mark VK3MD
12. Mark VK3IRV
13. Luke VK3UKW
14. Martin, David and rest of the EMDRC committee
15. Ararat council and Shaun Foy for the approval to launch from Centenary Park, Ararat
16. Northern Grampian Shire for approval to use launch facilities there
17. Everyone else at the Melbourne Raspberry Pi Group where this idea too birth ~3 years ago
18. The folks at Docklands Makerspace who have always been generous, allowed us to make use of their facilities to run our monthly sessions
19. Everyone else at EMDRC who has supported us in kind and spirit
20. Our contacts at CASA who patiently worked with us all through
21. Our families who tolerated all the mad scientist business we’ve been indulging in over these years

The night before – The launch team got together on the 3rd of September 2022 at 2100 on discord to confirm Go/No-Go for the High Altitude Balloon Launch scheduled for the 4th of September 2022, with a backup launch scheduled for the 11th of September (weather permitting, etc.). The team reviewed the weather for the launch day, equipment readiness, personnel readiness, chase car readiness, etc. and confirmed that we were ready to go for the launch. Trevor VK3TWC sent out an update to CASA on the night of the 3rd of September with the predicted flight path as a final confirmation. Trevor VK3TWC confirmed that CASA had raised a NOTAM (Notice To Airmen) for the YARA (Ararat Aerodrome) and Melbourne FIR for the duration of the launch.

The EMDRC team has shared responsibilities for many of the launch activities. Here’s a view of various tasks and activities owned by individuals in the launch team –

1. Rohan VK3TRO – Payload design & build + Part of the launch and recovery team
2. Mark VK3IRV – Design & build of Yagi antenna + Raspberry Pi to track Wenet and Sonde payload
3. Brad VK3BKQ – Design & build of Yagi antenna + Raspberry Pi to track Wenet and Sonde payload
4. Trevor VK3TWC – Strategy, logistics, communications, approvals, media, etc. + Part of the launch and recovery team
5. Rory VK3ASY – Payload design & build + Part of the launch and recovery team
6. Andrew VK3BQ with VK3EEK – Part of the launch and recovery team
7. Greg Boyles – Design & build of the filling apparatus + Part of the launch and recovery team
8. Chris Gommersall (Soon to be christened VK3PLS) – Design & build of the filling apparatus + Part of the launch and recovery team
9. Trystan J – Payload design & build + Part of the launch and recovery team
10. Andrew B – Part of the launch and recovery team
11. Andrew Lee – Photographer and part of the launch, recovery team
12. Mark VK3MD – Part of the launch and recovery team
13. John VK3PZ – Part of the launch and recovery team
14. Jack VK3WWW – Part of the launch and recovery team

Key launch variables – This section provides a view of the key launch variables that guided launch activities on the 4th of September 2022.

1. Scientific balloon – Hwoyee 500
2. Parachute – 36 inch spherachute
3. Gas – Pure helium gas
4. Weight of payload – 500 gm [350gm for Styrofoam box with pi, batteries, camera + 95gm for reprogrammed RS 41 radio sonde + 55gm parachute]
5. Ascent rate – 5.5 m/s (target)
6. Descent rate – 3.51 m/s (target)
7. Burst Altitude – 29,903m or 29.9Km (actual)
8. Archers line used to connect payload to the parachute and the balloon
9. Payload & radios – Styrofoam box with the following :
   1. Raspberry Pi Zero with a camera [Running WENET]
   2. Lora board connected to the Pi Zero W for purposes of streaming images (over Wenet)
   3. 1/4th Ground plane antenna
   4. Re-flashed Bureau of Meteorology Radiosonde (RS41) with the HORUS binary
10. Weight of the filling apparatus – 770gm
11. Necklift required – 554gm (1324gm – 770gm)
12. Launch date – 4th of September with 11th of September 2022 as backup
13. Launch location – Centenary Park Oval, Ararat
14. Launch time – 1000 Hrs AEST with recovery to be performed soon after
15. Frequencies in use –
    1. Wenet (image transmission) frequency : 441.200 Mhz
    2. HORUS (RS 41) frequency : 434.200 Mhz
    3. Simplex for local communications (between chase cars) – 146.525 Mhz
16. 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

Here’s the modelling we based our final balloon prep on –

Launch preparation – The team arrived at the launch site (Centenary Park Oval, Ararat) by 0840 and began setting things up in preparation for the launch. This included –

1. Rolling out the tarp, setting up the tables, getting all our equipment setup on the ground
2. Laying out the cylinder, safety equipment and and the gas filling apparatus on the tarp
3. Bringing out the balloon, parachute, archers line, etc. required for the flight and laying them in order
4. Performing final assembly of the payload including final tests
5. Setting up the tracking equipment so we didn’t have to spend time turning things on before we headed out for the chase
6. Putting on safety glasses and gloves required to handle the balloon
7. Turning on the radios to listen to local air traffic, make sure we were aware of any traffic in the vicinity at the time of the launch

Here are some of the pictures from the prep phase of the launch, taken at Centenary Park Ararat.

The balloon was filled with helium gas within ~25 minutes and was ready to be launched by 0930 but our launch window only opened up at 1000, so there was a bit of wait involved. Not having launched before we had no real idea how long any of the launch procedures were going to take in real world launch conditions. We had measured the winds at the time of filling, it turned out to be a wind speed of ~10 km/h which was great. However ~25 minutes later, the winds started picking up which meant that the inflated balloon was being tossed around. This made it harder for the launch team since we had to put extra effort to make sure that the balloon was safe, didn’t move around too much in-spite of the strong winds.

Once payload assembly was complete we turned on the Wenet payload including the re-programmed RS41 radiosonde. This allowed us to test reception locally and make sure we were able to receive data from both the Wenet and RS41 Horus payload. This turned out to be easier than I had expected, the dress rehearsals and pre-launch testing had paid off.

Over the last 2.5 years we’ve had multiple opportunities to test out most parts of the launch process other than securing the neck of the balloon and tying the payload to the balloon before letting it go. So obviously on launch day we were a bit clueless on the best approach to safely unmount the balloon from the filling apparatus, secure the neck of the balloon while ensuring the balloon was well connected to the builders line and rest of the payload it was going to carry up into the stratosphere. A call to Mark VK5QI helped save the day, we were told how to safely remove the balloon from the filling apparatus and secure it to the launch payload. We followed Mark VK5QI’s advice and we were ready to launch a few minutes later.

Chase & Recovery – The next best part was tracking the re-programmed RS41 payload while watching pictures being beamed down from the Wenet module. Multiple chase cars were involved in the chase with different chase cars starting their chase from different points. The launch team packed up, got into their cards, started following the trajectory of the balloon using their chasemapper setup and followed the payload until the final landing point.

The entire chase lasted around 2 hours with the payload coming to a rest along 18 Sterry Road, Marong. Jack VK3WWW, John VK3PZ and Mark VK3MD were the first to arrive followed by Trevor VK3TWC, Rohan VK3TRO + Andrew Lee next, followed by Rory VK3ASY + Chris G + Andrew B, Andrew VK3BQ along with VK3EEK and their kids and finally Luke VK3UKW. The group then split up with a large number catching up at the Beechworth bakery in Bendigo to sample some of the local pies and pastries.

The team had hidden some Iced Vovos within the payload, it was now time to take them out of the box and see what they tasted like. Here’s Rohan VK3TRO pictured with the bag of Ice Vovos in his hand.

The balloon burst at a height of ~29.9 Km, which was very close to the height we had planned and done our modelling for i.e. 29.8Km. The actual landing site was also quite close to the predicted landing site as per the modelling performed earlier in the morning. The chase is equally if not more exiting than the balloon launch. It was absolutely fantastic to see such a large number of people tracking the balloon remotely, a good number chasing the balloon in their cars and getting to the landing site ~2hours later.

The RS41 Horus payload is programmed to capture a number of environmental parameters which are then captured by the tracking stations and uploaded to sondehub.org. This data is available for everyone to access and see. The following pictures provide a detailed view of the various flight parameters including –

1. Altitude over time
2. Ascent rate and Descent rate over time
3. GNSS Satellites in Use over time
4. Temperature, Humidity over time
5. SNR (RS41 with Horus) over time
6. Battery voltage over time (RS41 with Horus)
7. Packet count over time (RS41 with Horus)
8. Per-Receiver Packet count over time (RS41 with Horus)

You can also access the detailed graphs over here – <Link>

If you are interested in learning more about High Altitude Ballooning please head over to – https://hack2.live/high-altitude-ballooning/. If this has got you excited and if you are keen to join the High Altitude Balloon group please drop us an email, say hi. Please write to us at trevor at hack2 dot live or hab at emdrc dot com dot au if you have any questions. I’ll do my best to respond.