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My daughter, age 9, had her school science project fair today. Between XYL and Daughter they decided a U4B balloon tracker would be a good idea. Timing: poor (in the run up to Dayton).?

MANY thanks to Dave VE3KCL for LOTS of time spent on advice and Muhsin TA1MHS for sending some balloons he had. This was my FIRST ever balloon launch, the U4B project started in 2015 but I have always done the hardware and firmware design, while Dave VE3KCL launched the actual test flights from Toronto.?

We built the tracker in bits of spare time over the last week. All hobbled together with whatever materials were available. Antenna wire is approx #40 (0.08mm diam) from an old relay, measured out to 5m. GPS antenna is the usual 0.33mm QRP Labs wire, twisted tight for 2.5cm for a feedline, then 45.5mm dipole legs. 6 solar panels 39 x 19mm each, in series; stuck to pink polystyrene using superglue. Yes we discovered it dissolves?polystyrene. So a lot of fishing line tied here and there to hold it together. The fishing line (thinnest we could find locally, which is not particularly thin) was glued with superglue to the relay wire at approx 20cm intervals.?

Anyway, so, today was the day of the school science fair. Everything was wrong. Wind (about 10km/hr, not huge but still wind); high level cloud, hundreds of crazy kids running around. School playground with power lines on 2 sides, tennis court fence on one side, and the school building on the other. Nightmare... we couldn't find any hydrogen but found helium in the local industrial estate. $10 for two balloons filled to 15g lift each, not bad. One balloon was to be used as backup in case the first failed (XYL idea, turned out to be a great?idea). The helium guys insisted we can't hot iron seal the balloon necks and we can't superglue them and a little coloured ribbon should be fine :-/? Nobody EVER listens to Hans so my protests were in vain...?

The wind was all over the place and I could not figure out which way it was blowing. Were we to be at one end of the playground or the other, was hard to know. The first attempt was a failure. The balloon left without its payload! The kids started a countdown 10, 9, 8 and by the time they got to 4 I was looking at the balloon and it was rising up, but my daughter still had the bottom of the antenna in her hand! Something had come untied. Then we discovered that the fragile solar cells and tracker had not fallen on the stones of the playground and smashed... but had by good fortune landed upon the noble head of the science lab teacher.?

Second attempt, tangled antenna wires, and I decided we were at the wrong end of the playground, so off we went dragging the balloon and a hundred following kids, to the other end... suddenly the wind just died and I said to my daughter, just start your countdown NOW!!! 10, 9, 8, all the kids yelling... they got to zero and my daughter didn't let go, she just froze. I guess the big moment finally came and nobody knew what to do with it. Let go, let go! And off the balloon went, straight up vertical like a rocket, in that only one temporary lull in the wind! Amazing.?

Even more amazing - it has reached about 9500 m altitude without bursting so apparently the gas people put decent helium in and my measurement of lift was correct.?

I was saying to my daughter, we'll do another balloon flight quietly and properly from the beach, after Dayton, with proper planning and preparation, and try and get one that gets outside Turkey. For today let's just be grateful if it gets out of the school playground. But here we are, it left Turkey already and well out across the Mediterranean.?

So it was an overwhelming success against almost ALL the odds...?

I took video footage and will edit a YouTube video soon. For now, the balloon can be tracked at:

and nicer:

U4B program: