About 2 months ago I received a message via this blog, from scout leader Andrew Anderson of 5th Hucknall Scouts, asking for help with a HAB project he and his scouts had planned. Some surprise monetary restrictions meant that having purchased a GoPro camera for their flight, they had nothing left for the rest of the project. After a short discussion I decided to help, and together we planned for the launch day. Initially the scouts were going to fly an Action Man toy, dressed as a scout, but apparently he’s put on a little weight in the last few years (I know that feeling) so Andrew opted instead to fly the scouts’ mascot, which you can see here looking at the GoPro camera:
The shape and size of the foam (appropriately decorated with green tape) is no accident – it’s the correct size to match the transmitting aerial that I built into the tracker module to be taped directly below:
As the launch date approached I checked the predictions. Not good. For the site and date we wanted, the winds would take Simon the Frog out to a wet ending in the North Sea. Frogs like being wet, but not that wet, so I searched for alternative sites. None would work, but if we changed from a Saturday launch to the Sunday then the winds were much more favourable, with Simon getting a dunking in the Humber instead of the sea! Well, he’d still drown, so Andrew suggested an alternate launch site further inland than the original one. Predictions for that site, and a Sunday launch, looked good so Andrew contacted David Miller at the CAA who kindly gave us permission despite short notice of the change of plan.
With the trackers tested and built into their payload boxes, and the car packed with the tracking equipment, gas cylinder etc., Julie and I drove up to Nottingham on the Sunday morning. As we arrived at the launch site the farmer was cutting the very long grass down to the field – just as well as we were in my car and not the 4×4! As we waited for the scouts to arrive, the farm cat came over to say hello, so that kept Julie occupied while I got the tracking PCs online:
Once the path was passable I moved the car down to next to the launch field, so we didn’t have to carry the kit too far and to make it easier to run the live video feed:
When everyone had arrived I explained how these flights work, with the balloon taking the payloads to an altitude where the balloon is as large as it can be (about the size of a small house!) at which point it bursts. The parachute then deploys bringing the payloads down to a soft landing in a field. Well that’s the theory anyway! Here I am showing that the parachute is about the same size as my head
After that I got the radio trackers running while Andrew put together the frog payload complete with GoPro set (hopefully) to “record”!
Now, normally if I ask “who’s good at tying knots?” at a launch, I’m met by a wall of silence. This time though I had several keen offers! Here’s the winner, who later signed as “knot boy” on my ThankYou card, doing his stuff on the parachute:
With both payloads ready and everything tied together I inflated the balloon, using helium this time rather than my usual hydrogen (apparently scouts are flammable, and there’s no such thing as a “fire-fighting activity badge”). This was an 800g balloon to carry 800g of payloads, and was inflated to give 2.3kg of lift meaning I had to use most of the gas in the medium cylinder I’d brought. With these figures I was expecting the balloon to burst at around 29-30km altitude.
Andrew then called local ATC to notify them we were soon to launch and check that it was OK to do so. Once the balloon was inflated to the correct lift (meaning the carefully filled and weighed bottle was lifted off the ground!) it was time to launch:
The rain started to fall almost as soon as we launched, so we quickly packed up as lunch was served. I checked online to make sure the other balloon enthusiasts were receiving the signals OK, which they were though one tracker was being received much better than the other test tracker. We suspect a component fault in that second one so it’s going to get some more testing soon in the lab. Lunch over, Julie and I set out after the balloon, with the scouts and leaders following after in their minibus. The chase car was set up with 2 receivers and we saw the balloon go higher and higher, comfortably beating the predicted altitude and eventually reaching an impressive maximum of 35.5km, putting it at the 27th position in the UK record table:
Other than that, the flight path was pretty much as expected, with the time at higher altitudes bringing the landing point a bit further west. So we had a slight change of plan when we realised that the landing would be west of a forest rather than east (either is good; in the middle isn’t!). Here’s the flight path in green/blue, and our route on land in orange. The reason for the 2 parachutes is that we only tracked one payload to the ground.
We weren’t far away from the landing site when we passed this interesting warning sign. Fortunately we landed outside this particular landowner’s property!
Back in the car, we soon got telemetry again as we got a bit closer, so once the map had updated we drove to the landing spot, meeting the scouts in their minibus on the way. We then drove right onto a track where we saw the bright orange and lime green parachute in front of us. Needless to say the scouts got quite excited to see their payload safe in the field next to the track!
With the payloads safely recovered, we posed for some photos:
I was presented with a bottle of wine and a card signed by everyone, which was very touching. It was great to see the smiling faces, and perhaps one of these young boys will be inspired to have a career in science or engineering?