The lengths we go to, to recover our payload – the Siren

Back in April 2012, The Lyons twins launched a weather balloon from their university in New Zealand (Launch site co-ordinates : -37.783115, 175.314520). I was fascinated to read what they included in their payload to aid recovery. First the twins describe their payload


1x Canon A560 – Still capture, programmed with CHDK to capture images every 5 seconds.

1x Fujifilm A170 – Video, only for the launch and hour of flight time.


1x SPOT Personal Tracker – Send updates via satellite every 10 mins, limited to 60,000ft (secondary).

Constructed a gimbal system to orientate the tracker with the sky.

1x TrackIt Personal Tracker – Very fortunate to have received sponsorship from TrackIt. A NZ based company that specializes in GPS tracking. Very lucky to have them on board!


1x Barometric sensor – kindly donated to us by a US company, Gulf Coast Data Concepts.

Can record down to what we need, and records temperature at programmable intervals.


1x Pizeo Siren system – Running off an Arduino board as a countdown device to turn the siren on to help with location once landed. Huge thanks to Gillzy for his patience, help and Arduino board. He’s a pretty top notch bloke

The siren in the payload

Here are exerts of their blog to describe the flight and THE SIREN.

T minus: a few days

We have had some great weather over the country in the past week. Initially we looked at launching on the 22nd, but we were unable to source the gas. We knew that the high over the North Island was moving eastward, so our window of opportunity was  limited. After running a few prediction through Cambridge University’s balloon prediction software (extremely handy!) we settled for the 26th, Thursday.

T minus:14 hours

On the eve on the launch, as I was rigging the parachute and other lines, Zac had a bit of a mare with the siren. The thing wasn’t working properly. He checked his coding, and his electronics, but alas no solution. He figured that the Ardunio board drained the batteries. The brand new 9V lithiums (cost an arm and a leg). The launch was not going to be postponed by a small hiccup like this, so Zac decided a major refit was in need. He ripped out the siren electronics and hard-wired a semi-fresh lithium to the siren, this meant that there was no timer, just full on wailing from take off to touch down. Problem solved.

The final checks were done,  batteries replaced/charged and the gear list checked off. We checked the predictor again, but it still hadn’t changed much, putting impact southeast of Matamata very close to the treeline of the ranges. Nothing ventured, nothing gained right? It was on.

I asked the twins how the siren faired. Zac said, “We tracked the unit with a SPOT satellite tracker as our secondary and another GPS unit that we source locally. We didnt want to jump into amateur radio, so we knew that the tracking units we had would have an altitude limit, but we were fine with this, hoping that it would start again as it descends.

We lost the balloon at 17km, (we knew this) and lost it for about 40 mins! we had a rough idea where is was going to land, and 40 mins later the GPS units updates and directed us straight to it! The siren was temperamental, the electronics failed the night before the launch so we were sceptical whether the battery would last the entire flight, which it didnt! but the GPS located it no problem!”

For the full story of their launch adventure go to

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s