Babbage’s big jump: the aftermath

If you were following the live feed and our live tweets on Saturday, you’ll know that Babbage the bear’s attempt to beat Felix Baumgartner’s stratospheric parachute jump with a couple of Raspberry Pis was a bit of a curate’s egg. It was a very blustery, cloudy day at the launch site, and while Babbage made it into the stratosphere (beating the world record – also held by Dave Akerman, who was behind this weekend’s launches – for highest pictures transmitted live from an amateur device), he did not separate from his platform properly, so rather than leaping into the void, he plummeted, platform and all, when the balloon burst at 41.109km, and fell to earth under the tatters of the balloon. We were able to use GPS to work out where he had landed (in the middle of a barley field somewhere in rural Berkshire), and retrieved him. Here are some pictures from Saturday (thanks to Anthony Stirk for the pictures which I didn’t take – you can tell which ones they are, because I’m in them): The day opened with a bacon muffin. And a radio mast. It was a VERY blustery morning. Here Dave struggles manfully against the wind, which is trying to blow our balloon into a bramble patch just after filling, before the payload had been attached. Despite planning every minuscule detail, Dave forgot to make a capsule for Babbage’s parachute. Fortunately, there was an empty Smarties tube in the back of our car. Dave recorded a time-lapse video of the preparations for launch (and selected a doozy of a frame for the still you can see now – not impressed, Dave): We ended up using three lines to stabilise the balloon for launch. Babbage got away safely. Dave does a happy dance of glee. Here’s the launch in all its very windy glory: We retreated to Mission Control (Dave’s house) to monitor the flight. Back to Mission Control (Dave’s house) to watch data coming back from the payload. Both the capsule and Babbage himself were equipped with Raspberry Pi camera boards. While waiting for the balloon to burst, we were able to watch images like this streaming back from the stratosphere. Dave’s currently uploading all the pictures taken from both parts of the payload to Flickr.  An hour’s driving towards a GPS location and a half-hour’s scramble through hedges and fields later… We had to climb through a few thickets full of brambles and nettles from the car before we could get to the barley field where Babbage landed. Dave went to get the wreckage alone so we didn’t disturb the farmer’s crop. As you can see, the separation hadn’t worked – all the bits of the payload are still attached to each other. And this resistor is why. A program trips in the Pi at 39km up and sends current through it, which is meant to heat the whole assemblage up and melt the nylon cord. It has 5 seconds to get from -50C to +200C – which wasn’t enough at 39km up. As you can see, no melting occurred. For the next launch, Dave added more batteries, which worked like a charm. Back at the car. If Eben had hair, it’d look like he’d just crawled through a bush too. (Mine looks like I’ve just crawled through a bush because I’ve just crawled through a bush.) So Dave, dissatisfied with the performance of that 5p resistor, decided to launch again on the Bank Holiday Monday. (We didn’t join in this time, largely because it’d have meant another drive of some hundreds of miles.) And this time, the separation worked like a charm. Dave’s second attempt on Monday ended up being covered by the BBC, the Independent and the Register, so you can read all about it there. He’ll be being interviewed on BBC Radio Berkshire this evening from 4.30pm for a few minutes – and the BBC is also sending someone from Click (the radio edition) to chat to him later on today. He’ll also be updating his own site with a report on the flight later on – check back soon! If you want a Babbage of your very own, whether you want to send him into near-space, or whether you just fancy something to cuddle, you can buy him at the Swag Store. All profits on Pi merchandise go straight back into funding the Raspberry Pi Foundation’s educational work. And Babbage is just the right size to be hollowed out and filled with a Pi, batteries and a camera board, and just the right weight to be put under a balloon and sent into the stratosphere to take some amazing pictures.

URL: http://www.raspberrypi.org/archives/4733