EMDRC Pre-Launch Countdown Session – 24/8/22

The EMDRC High Altitude Balloon (HAB) team got together on the 24th of August 2022 to work through launch countdown activities as part of the High Altitude Balloon Launch scheduled for the 28th of August 2022, with a backup launch scheduled for the 4th of September (weather, etc.).

The EMDRC (Eastern & Mountain District Radio Club – https://www.emdrc.com.au) High Altitude Balloon (HAB) group has been working towards it’s first launch here in Melbourne. The launch has been almost three years in the making, with COVID being unfortunately responsible for a lot of the delays. The EMDRC HAB group has obtained approval (also called instrument) from CASA (Civil Aviation Safety Authority) including approval from the Ararat council for use of use of crown land for purposes of the launch.

The Pre-Launch Countdown session on the 24th of August 2022 was attended by –

1. Rohan A / VK3TRO
2. Mark D / VK3MD
3. Mark / VK3IRV
4. Brad Q / VK3BKQ
5. Trevor W / VK3TWC
6. Luke / VK3UKW
7. John / VK3PZ
8. Chris Gommersall (Soon to be christened VK3PLS)
9. Trystan J

This post provides a summary of what was discussed –

1. The predicted flight path (for the launch on the 28th at 0930 AEST) based on modelling performed through the week confirmed that it was very likely that the payload would end up in the ocean.
2. The predicted wind speeds for the time of the launch were getting to a point where it could jeopardize the safety of the payload including our ability to launch.
3. Tweaking of the various levers at our disposal i.e. gas in the balloon, weight of the payload, ascent rate, etc. was not going to reduce the flight risk for the given weather conditions.
4. Having parachutes of different sizes could help us change the descent rate (increase it with a smaller parachute) but again this wasn’t going to significantly reduce flight risk for the given weather conditions.
5. It was agreed that the upcoming launch would be re-scheduled for the 4th of September 2022 for 0930 Hrs with a backup scheduled for 11th of September 2022.
6. It was agreed that the EMDRC High Altitude Ballooning team would catch-up again for a Pre-Launch Countdown meet on the 31st of August 2022 with a final Go/No-Go scheduled for the 3rd of September 2022.
7. It was decided that Trevor / VK3TWC would reach out to CASA, request cancellation of the NOTAM request.
8. It was agreed that Trevor / VK3TWC would reach out to the Ararat Council requesting a re-schedule of the launch to 4th September at 0930 Hrs AEST.

Key launch variables include –

1. Scientific balloon – Hwoyee 500
2. Parachute – 36 inch Spherachute
3. Gas – Pure helium gas
4. Target ascent rate – ~5 m/s
5. Target descent rate – ~3 m/s
6. Payload & radios – Styrofoam box with the following :
   1. Raspberry Pi Zero with a camera
   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
7. Previously agreed launch date – 28th of August 2022
8. New launch date – 4th of September 2022 with 11th of September 2022 as a backup
9. Launch location – Centenary Park Oval, Ararat
10. Launch time – 0930 Hrs AEST with recovery to be performed soon after
11. Frequencies in use –
    1. Wenet (image transmission) frequency : 441.200 Mhz
    2. HORUS (RS 41) frequency : 434.200 Mhz

The predicted flight path for the 28th of August 2022 based on the above launch variables is as follows –

The predicted weather conditions for the 28th of August 2022 is as follows –

The team has shared responsibilities for many of the launch activities. Here’s a view of ownership of the various tasks –

1. Rohan A / VK3TRO – Payload design & build + Part of the launch and recovery team
2. Mark / VK3IRV – Design & build of Yagi antenna + Raspberry Pi based tracking setup to track Wenet and Sonde payload
3. Luke / VK3UKW – Design & build of tracking setup based on the Raspberry Pi
4. Brad Q / VK3BKQ – Design & build of Yagi antenna + Raspberry Pi to track Wenet and Sonde payload
5. Trevor W / VK3TWC – Strategy, logistics, communications, media, etc. + Part of the launch and recovery team
6. Rory / VK3ASY – Payload design & build + 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. Mark / VK2MD – Part of the launch and recovery team
11. Jack B / VK3WWW – Part of the launch and recovery team

The EMDRC High Altitude Balloon team welcomes new members. Please write to us if you have any questions or if you are keen to be part of the launch group.

Read more about High Altitude Ballooning and get started with your own High Altitude Balloon journey at https://hack2.live/high-altitude-ballooning/