Canon Camera Setup

Screen shot of the setting up.

So this morning we woke up and took our camera out of the freezer, as you do. We left it there overnight to test that it can work under freezing conditions. It is a Canon PowerShot A810 and has had the Canon Hack Development Kit (CHDK) installed so we can upload a script to continually take photos on a loop every few seconds. The kit itself runs directly from the SD card of the camera, without actually touching the existing firmware. This only works on Canon cameras and for each camera there is a specific file to download. A full 'how-to' can be found here.

There are a few example scripts around on the Internet but nothing that exactly fitted our needs, so I wrote our own. It's quite simple in that it takes photos on a loop, with the ability to change the time period between the photos on the camera itself.  You can see the script here on our GitHub!

We also thought that this blog was lacking a graph, so here we go:

One of the other great benefits of the CHDK is it has the ability to write log files. This means we can see what the camera got up to while in the air - including making use of the thermometer within the camera! This graph shows how the temperature dropped over time against the amount of photos taken. We managed to take over 2000 photos over the four hour time period. The period between the shots was 12 seconds, but I think we could reduce this, maybe by half. We might try this test again to see how it fares. Another thing to bare in mind is that our home freezer only got to -15C, where as in the Stratosphere it can get to -50C.

As you may have seen in our Payload Part Two post, we will have the camera facing down, the idea being that we get some good ground shots of our fantastic Forest of Dean scenery on the way up in addition to some general 'Earth' shots when we are up at 100,000ft. With the GoPro on the side, hopefully we have all angles covered!

Four Day Weekend

Another busy few days at STRATODEAN HQ. We found out last weekend that our CAA application has been accepted with all our requested dates gaining approval. Yey!

We've been trying to make the most of the extra long bank holiday weekend and tick some more jobs off the old to-do list.

We visited our launch site to get a greater idea of how to plan our launch day, just basic things like parking (somewhere where we don't have to drag our helium too far!), where to set up our tarpaulin and equipment etc.



The helium has been purchased! After much umm-ing and ahh-ing he decided to take the hit and order a jumbo-sized canister (BOC cylinder size 'L'). This beast holds 9m³ and weighs 76.5kg. We were hoping the medium-size would be sufficient (BOC size 'T') but our calculations predicted we would require approximately 4m³. Even though this figure was rounded up, the medium's 3.6m³ of helium would have been little too close for comfort. We were hoping to procure the helium from a local company but all those approached required us to have an account with BOC before they would deal with us. In the end we ordered from balloonhelium.co.uk who seems to be a common HABer's port of call.

Our balloon (plus a spare), parachute and cord have arrived from Random Solutions (thanks Steve!). The latex balloons are tucked away in storage until needed but we took the parachute for a little (highly technical) test run a little earlier...


Still on the to-do list for the weekend ahead:

• Finish testing Canon camera and CHDK.
• Make balloon filler.
• Attach cord to payload and duct tape.
• Make decision on hand warmers and make necessary payload modifications.
• Check credit on backup tracker.
• Check credit on 3G dongle.
• Write 'night before' list.
• Write 'on the day' list.

Finally, Happy Easter from the resident STRATODEAN HQ Bunnies.

Summer wishes you a Happy Easter from her cardboard castle.

Payload - Part Two

We've been making some real progress with the payload this week - if you missed our first post detailing how we constructed our polystyrene box you can see it here.

We've made a video which we hope will explain things further.  Be sure to read below for more information and pictures.

The majority of the work has been organising the layout of the components within the payload and making compartments inside the box to offer them extra protection and insulation. Basically we need everything to fit nice and snug! Here come the photos:

Drilling a hole for the camera lens with a hole cutter.

The hole. 

We tested a few options based on recommendations by other HABers for cutting out this aperture, such as using metal cookie cutters or just cutting it freehand. This method however gave us the cleanest finish. The cookie cutter method proved particularly tricky as our polystyrene has a closed cell structure. This is the property that makes it waterproof in case it lands in the world's deepest muddy puddle or the English Channel etc. It is therefore very dense and resilient to cookie cutter pressure!

A spot of hoovering.

Freehand trimming was easiest with a fine hacksaw blade.

Layer 1 - the base of the payload.

The first layer of polystyrene shown left is actually one layer of our 1" polystyrene sitting on top of the base of our payload box. Here we have the GoPro resting on top and facing outwards with a square cut into the side wall. The backup tracker is slightly sunken down into the polystyrene level and a space for the digital camera has been completely cut out so it can face down and the lens can extend out through the circle cut out of our payload base.

A quick weigh of the payload.

It was essential for us to check our payload mass as we added our internal compartments - the polystyrene can add a surprising amount of weight and we didn't want to go overboard and let the weight creep up. It doesn't matter how well organised and pretty it looks - it's got to get off the ground after all! Luckily it was all under control so we set about making Layer 2.

Layer 2 in the making.

Our tracker and battery pack in position.
The space on the right is to secure the GoPro in position.
The hole in the middle is for the aerial.

The tracker's nice and snug.

Layer 2 in situ.

With all of our components housed and layers completed, we decided our payload box had approximately 2" of excess height. When we originally designed the box, we opted for a cube mainly for ease/it seemed pretty logical, and well you have to start somewhere don't you? Now in hindsight this extra polystyrene was an unnecessary weight so we trimmed it off.

Things get a little nervy as we measure
what's about to get the chop.

The moment of truth. With an upturned dust bin lid acting as a polystyrene dust receptacle. Resourceful.

Bye bye extra weight.

Our new low profile design being sanded.

Time to make it a hat.

Our double layer lid being glued together.

Another step closer..!

We've only just gone and bought a balloon, parachute and some nylon cord!

Cue happy faces..!:

Still on the To Do List...

The CAA Application has been emailed off but still plenty to do! 

We made the paper!

We made it into the Forest Citizen.

Night Sky Photos Two

Here is are few from our second attempt at taking some photos of the night sky. Again from Symonds Yat Rock, again very cold! The results from our first try can be seen here.

Symonds Yat

River Wye

First Polaris Attempt

Symonds Yat

Payload - Part One

There's pretty much two options available for creating the payload:

• Buying a pre-made polystyrene (styrofoam) insulated box. Commonly referred to as fish/cold boxes that are used as packaging for transporting chilled goods. Examples can be found here.
• Making your own custom made design from polystyrene sheeting.

After a bit of research, we decided on making our own. This would allow us to create precisely the size we needed, something that our components would fit tidily into and into which we could also include internal compartments. Furthermore, the available pre-made sizes seemed to be rather heavy so we figured there was a weight saving to be made with a DIY box. A heavy payload before we'd even filled it with components = bigger balloon, more helium, bigger parachute, which in turn = more £££s. Something to be avoided wherever possible.

Quick drying, colourless, anti-aging,
and waterproof.

After a brief chat with the good people on UKHAS we were directed to the Hindleys website. We purchased two sheets of the 600mm x 1245mm x 25mm Blue Styrofoam. We only needed the one - but better safe than sorry. We were advised that the blue styrofoam made less mess when cut than the white. Less hoovering, excellent. We also purchased some UHU Por glue from eBay. Regarding cutting the polystyrene, we looked into the benefits of a hot wire cutter but since we were only cutting straight lines we decided to take our chances with household tools.

Testing various cutting options!

Saw was rubbish. Bad idea.

Large non-serrated knife. Nope.

Bread knife. Not great.

The trusty Stanley knife ended up being the tool of choice.

Measure twice, cut once and all that.

Planing and sanding for a smooth finish.

Some gluing.

Putting it all together!

Night Sky Photos One

Last week we had our first attempt at taking some photos of the night sky. Still playing around with all the different SLR settings but we've uploaded some of our first efforts below. These were taken at Symonds Yat Rock on a very cold evening!

Symonds Yat 

Symonds Yat Rock 

Symonds Yat Orion

Symonds Yat Flag

Backup Tracker - just in case!

We're thinking about putting my GoPro Hero 2 into the payload to get some hopefully decent video of the journey up and down. This is quite an expensive camera and I don't really want to lose it(!), so have decided to put in a backup tracker to work along side the primary radio tracker and act as a bit of a fail safe in recovery.

I'll do an extensive primary tracker write up very shortly - it has been quite a lengthy process and we're still not completely finished with it.

A key feature of the backup tracker must be that it keeps working whatever happens! We want this to be a completely separate device to the rest of the payload and work in a different way so we have an alternative should the primary fail. Initial thoughts were to put in some kind of mobile phone that had a GPS chip in that could text us it's location coordinates, but these were heavy and setting them up to continually send their position seemed an unnecessarily large hacking task. I thought that there must be some kind of device that did this already so I began searching around on eBay, it didn't take long:

Bingo.

It has a decidedly Made in China feel about it, not more so evidenced by the 'Chinglish' instruction manual that was included, but it does everything we need! It even came with two rechargeable batteries and a charger.

I got a SIM card from the shop and stuck a fiver on it to test it out. This thing is great, in its most simple mode all you have to do is turn it on and leave it to do its thing, you just dial the SIM phone number from another mobile and it will answer and hang up the call. A few seconds later you receive a text message with the location of the device - along with a link to Google maps if you want it! You can also set it so that you automatically receive a text message every 30 seconds or so to a predetermined set of numbers. Interestingly you do all of the configuration of the device from another mobile - sending commands via text.

If you want to get more advanced, you can take advantage of its GPRS functionality. Instead of sending information via SMS, it will use the mobile internet (GPRS not 3G) to send its location to a central server on the Internet. You can then view it on a map from your PC/Mobile. The benefits of this is it probably cheaper than the 12p a text you pay on SMS mode and you get the added Internet tracking functionality.  The problem however is that GPRS (2G) signal is not as widespread as the GSM (1G) network so if it landed in some hills or another forest, we need to use the signal that is most likely going to be available.

For us, I think we are going to leave it in SMS mode and have it send us a location every minute or so. We're expecting the mobile signal for the device to be lost at some point during the flight so that is another consideration we need to think about. The main purpose of it is for us to use it when the payload is back on the ground waiting to be found!