Ava High Altitude Balloon Project

Edit : Daves write up here : http://www.daveakerman.com/?p=1469

Its been an interesting weekend in HABing, a huge number of flights over Europe. SP9UOB’s SEBA flight continues over the furthest reaches of Russia as I type this. Together with Dave Akerman we came up with a plan to do something a little interesting. There is a world record for the highest altitude paper plane by a certain Mr Haines of The Register. Lester has always been a fan of the balloon stuff and his existing record of 27km always seemed a little low to us High Altitude Ballooners.

So after a brief conversation one evening we decided to have a pop at it. The tracker for the plane was my new pico board the PAVA R9. Featuring a ATMega328P-MU running at 2Mhz and a TCXO equipped SI4060 RF chip the tracker weighs in at a paltry 2g with antennas. Running from a step up board to 1.8V in theory it should run for 24 hours from an AAA battery :

So the plan was simple make a paper plane, after some very brief bit of testing I opted for a a flying wing style plane which met my criteria of :
a) It sort of flies
b) no pointy bits
c) Somewhere to put the tracker

Dave kindly supplied some pink A1 Card which we cut into 2 A2 pieces to construct the plane. Liveries were added and trackers installed in the “nose cone” :

The tracker was sealed in with some obligatory pink gaffer tape and an cord attachment was put on the rear.

Mean while Dave made a Pi up in a box with some carbon fibre runners and resistive cut downs. The glider would rest on the runners and be held in place with a cord to be severed by the Pi at a predetermined altitude and location. As its technically not permitted to drop stuff over the UK without a parachute we opted for dropping the plane over the North Sea.

Originally we were going to fly two gliders but with the ground winds picking up we decided to leave one on the ground. Dave’s Pi was called CLOUDY and the plane was called SNOW. Additionally a 3rd tracker called WANNAB1 was attached above the Pi, however this tracker appeared to have a damaged antenna and didn’t work for the flight.

With the wind gusting judging the neck lift of the 1600g H2 filled balloon was sketchy at best. We aimed for 2m/s which we seemed to get on launch, more though luck than judgement. Climbing up into the sky other receivers around the UK and Europe started to receive the transmissions from both CLOUD and SNOW. CLOUD was transmitting SSDV images back, however the weight of the paper plane had pulled the payload downwards so we got some nice ground images :

As the sun started to set Dave’s CLOUDY returned this wonderful image showing Venus above the sun setting below the horizon :

Both CLOUDY and SNOW continued climbing and entered the extremely fast winds at times touching 300kmph the balloon moved out of UK Airspace and towards Europe. At 16:14:21 as the balloon crossed longitude 4 and at 31849 meters altitude the Pi activated the FET that heated up the resistor and severed the connection between the paper plane and the balloon.

SNOW began its initially rapid decent back towards Earth. It was obviously from the decent rate it was stalling, gliding, stalling but followed a fairly straight path down towards the Netherlands.

As its passed through the cold zone on the way down the GPS, which was not insulated particularly well probably dropped well below -50’C and stopped working. The radio continued transmitting however. The GPS did briefly pick up and returned some valid data around 3km altitude. Stations monitored it pretty much to the ground but it was just transmitting 0’s for location information. PD5DJ immediately went out to location it but was unable to pick up any signal. At this time the paper plane remains missing.

Edit : Wonderful 360′ of the flight path from Geoff Mather  : http://360.g8dhe.net/HAB_Flights/2013_Flights/Snow_20131228/Cloudy_and_Snow.html

CLOUDY continued onwards rebooting twice as it attempted to cut the non existent second plane and finally itself from the balloon. Probably due to cold causing a lack of volts the cut down over Poland of the Pi didn’t work and CLOUDY continued onwards to the Ukraine before its batteries gave out still in the air.

With a maximum altitude of 31849m this beats the previous world record of 27307m by a considerable amount. On behalf of Dave and I it will be submitted to the Guiness Book of World Records in the new year. Additionally as a side note the current paper plane distance record is about 260 feet, SNOW covered 63km in a straight line howwever I suspect we won’t be eligible for this record. Its certainly more than James May’s 26 miles attempt.

Thanks to all the trackers who help with this record attempt and to Dave, Leo and Julie. Cheers to Ara for assistance with the code. Raw data here :

CLOUDY CSV
SNOW CSV