Over the next three days, we have 30 educators arriving at Pi Towers to learn how to build, launch, and track a High Altitude Balloon (HAB). For the uninitiated, Skycademy 2016 is our second CPD event which provides experience of launching balloons to educators, showing them how this can be used for an inspiring, project-based learning experience.
This is my first year preparing for Skycademy, and it has been a steep but worthwhile learning curve. Launching a HAB combines aspects of maths, physics, computing, design and technology, and geography, and the sheer scope of the project means that it’s rare for school-age children to get these types of experiences. It’s great news, then, that Raspberry Pi have the in-house skills, ambition, and commitment to run such things, and train others to run them too.
Skycademy runs over three days: on the first day, delegates form teams and take part in several workshops aimed at planning and building their flight. Day Two sees them launch, track, and recover their payload. Day Three has them regroup to reflect and plan for the year ahead. The support doesn’t end there: our Skycademy graduates go on to take part in a year-long project that will see them launch flights at their own schools and organisations, helped by their own students.
Tracking tomorrow’s launch
If you’re interested in watching the launch tomorrow, you can follow our progress by searching for #skycademy on Twitter. You can also use the links below to track the progress of different teams. Today, you will begin to see their payloads appearing on the map, and tomorrow you’ll be able to follow the chase.
Our current launch plan is to set the balloons free slightly to the west of Cambridge around 10am, but we’ll be posting updates to Twitter.
If you aren’t lucky enough to be taking part in Skycademy today, don’t worry: we’ll be making lots of resources available in the near future for anyone to access and run their own flights. Alternatively, you can also visit Dave Akerman’s website for lots of HAB information and guides to get you started.
Welcome to Dan Fisher’s ‘Fun with HABs’
I recently found out what lay in store for our latest crop of educators when I took part in a test launch two weeks ago…
We made our way to the launch site at Elsworth, Cambridgeshire, feeling nervous and excited. We arrived at 09.30, as experts Dave Akerman and Steve Randall were already starting to assemble their kit. The hope was that we might actually be able to break the world record for the highest amateur unmanned balloon flight. Dave and Steve are continually leapfrogging each other for this title.
The payload Dave is making in the picture weighs about 250g and consists of a Raspberry Pi A+ connected to Pi in the Sky (PITS) and LoRa boards. The lighter the payload, the higher the potential altitude. The boards broadcast packets of data back to earth, which can be decoded by our tracking equipment.
Surprisingly, the payload’s chassis assembly is hardly high-tech: a polystyrene capsule gaffer-taped to some nylon cord and balsa wood, to which the balloon and parachute are attached. For this launch, Dave and Steve used hydrogen rather than helium, as it enables you to achieve higher altitudes. Having no previous experience working with pure hydrogen, I had visions of some kind of disaster happening.
We weighed the payload to calculate how much hydrogen we would need to fill the balloon and ensure the correct ascent rate. Too much hydrogen means the balloon ascends too quickly and might burst early. Too little hydrogen results in a slow balloon which might not burst at all, and could float away and be lost.
After Dave filled the balloon with hydrogen, we attached the real payload (lots more gaffer tape) and we were ready for a good ol’ launch ‘n’ track. However, as is often the case, it didn’t exactly go to plan…
Home, home on the range
Picture the scene: two Raspberry Pi staffers are driving off-road through a military firing range. Behind the wheel is Dave Akerman, grinning broadly.
“It’s so much more interesting when they don’t just land in a ditch,” he says, speeding the SUV over another pothole.
We’ve tracked our high altitude balloon for two hours to an area of land in Thetford Forest, Norfolk which is used for live ammo practice: not somewhere you’d want to go without permission. Access is looking unlikely until we get a call from the nearby army base’s ops team: we’re in. We make our way past the firing range and into the woods.
After tracking as far as we can by car, we continue on foot until we spot the payload about ten metres up in a fir tree with very few branches. There’s no way of climbing up. Fortunately, Dave has come armed with the longest telescopic pole I’ve ever seen. It even has a hook on the business end for snagging the parachute’s cords. I act as a spotter as Dave manoeuvres the pole into position and tugs the payload free.
Giddy with the unexpected success of our recovery, we head back to the SUV and make for the exit, only to find we’ve been locked in. Scenarios where we’ve unwittingly become contestants in the next Hunger Games cross my mind. Armed only with long plastic poles, I worry we might be early casualties.
After feverish calls to the base again, they agree to come out and free us: a man in a MoD jacket dramatically smashes the lock with a hammer. We race back to Cambridge HQ, payload in hand and with a story to tell.
That’s it for now; look out for our post-Skycademy follow-up post soon!