New Heights - Part 5

High Altitude Weather Balloon

Nolan Sobel-Read

Issue 78, January 2024

An update from high school student, Nolan, about getting his STEM project into space.

In our January Issue 66, we introduced you to a young secondary school student, Nolan Sobel-Read, who needed funding to build and launch a high-altitude weather balloon and take measurements high up in the stratosphere (That’s over 30km in altitude or roughly 100,000 feet!).

Nolan outlined the goals for the project and what electronics he needed. We were only too happy to help out, and started sourcing the parts Nolan needed.

As a trade, we’ve asked Nolan to document his journey so that we can share it with our readers who may want to do something similar or be inspired by the work that he’s doing.

The following is the most recent update on Nolan’s project progress. We will publish more throughout the next few issues as Nolan’s project progresses.

Hi Everyone! It’s Nolan again. Here comes another update about my balloon project.

I wrote in my last article (Part 4 in Issue 75) about how we were having some problems with the code. I am happy to say that now many of those have been resolved.

The code file we had been working on ran almost everything right, except that when it tried to send the data over satellite, it came up with an unknown error that we couldn’t fix. Sending over satellite worked on the example code, but not ours.

We tried a number of things, but finding the error in such a large file was like finding a needle in a haystack. So, after some trying we decided to migrate our code into an example file we knew worked, and when it broke, that was the error!

Through that process, we worked out that there was an update that needed to be made in the board itself. I went on a deep-dive into the artemis files and changed a dozen or so lines of code. Fingers crossed it works now, we will finish those tests once school starts again in late January.

We have also made significant progress in the hardware side of things too. We ran tests on a computer to calculate the power draw of the artemis so we can determine the size of the battery. This is very important because we have to stay under roughly 1kg of payload to maximise the altitude that the balloon can go to. The lighter it is, the higher it will go!

As you can see on the photo, the power draw varies greatly, jumping up and down at intervals. This is because of the increased energy used when transmitting over satellite.

On average after 30 or so minutes the Artemis drew 308 mW, but varied all the way between 49.7mW and 1.52W!

This amounts to roughly 650mAh, as opposed to almost 10 times that for each camera. Factoring in the extreme cold and buffer, that would put us way overweight only factoring in the batteries, depending on which battery type we use. Hence, we have decided to only power the Raspberry Pi camera that my mentor Cameron from SAPHI Engineering is lending me, and the lightdow will be powered using its internal battery until it dies. We will also send up a super lightweight timelapse camera for a different angle.

This is why it was very important to remove the heater once we worked out that we didn’t need it, as it would draw a lot of power, and therefore a lot of weight!

Using this data and a parachute calculator, I will use a parachute that is around 48 inches wide, or a bit over 1 metre. This will have a decent rate of a bit more than 4 m/s, which is optimal. Too fast and you can cause danger to the payload, people, animals and property, but too slow and it can drift hundreds of kilometres before landing in extreme cases.

Currently we are aiming for a launch during the April school holidays, or around then.

That’s all from me, looking forward to updating you more soon!

Nolan Sobel-Read

Nolan Sobel-Read

Year 11 Student - Hunter School of the Performing Arts, Newcastle Australia