Dave Akerman

This was a more ambitious launch day than previously, with 2 flights and 3 payloads.  Also it was the first time I had put items outside of the payloads to photograph, and the first time I’d used hydrogen.  It was a joint launch with fellow “balloonist” Anthony Stirk who had flown once previously plus he helped on the James May Man Lab show when they flew 2 balloons, one with hydrogen.  We also had the help (vital it turned out) of another enthusiast Ed Moore.  Here we are after the payload stand fell over!

First launch was of the “Buzz” payload (not to be confused with the Buzz Lightyear toy that hitched a ride later on the “Cloud” payload).  This was an attempt of the amateur world altitude record, using a tiny payload weighing 50 grams, underneath a fairly large balloon with hydrogen.  I was hoping this would at least exceed the 41km of my current UK record, and in theory (with a lighter payload and hydrogen vs helium) it should at least have a chance.  Here’s Ed holding the balloon.

And here I am launching it.

We didn’t immediately chase this balloon – the plan was to launch the second balloon first, chase that (it has cameras so is a lot more valuable) then go and collect Buzz after.

The second balloon has Anthony’s “Ava” payload underneath it, in his trademark bright pink colour, then my Cloud payload under that.  Ava carried a Canon camera with a heated UV lens filter, whilst Cloud carried a Canon camera and Kodak camcorder.  We also added Anthony’s little camcorder on top of Cloud.

Cloud also had some other extras.  First was a soft toy Buzz Lightyear.  NASA have put a Buzz Lightyear into space, on board the Space Shuttle and then the International Space Station, but even they didn’t put him outside into space!

Second was a Radiometric logo (Radiometrix make the radios that almost all amateur balloon flights in the UK carry).

With both payloads completed, the balloon was inflated and everything tied together by Ed using his super-strong knots (more on those later).  We then walked into the launch field with the payload train strung between us:

After the launch we packed the cars then went back to my house to quickly check online and to plan the chase.  We had 3 cars – mine with Julie, Anthony’s with Ian and Katie, and Greg was in his own car.  The first two were equipped with radio receivers to help with the tracking, and in my car I was using my LCD dash display for the first time, neatly (or otherwise!) sat in an air vent:

Predictions for Ava/Cloud were for south of Guildford, so we chose a likely place and set our sat navs for there.  Anthony’s took him through Bracknell whilst mine took us via the M25.  En route Julie and I checked the live prediction and that said it would be closer to Dorking, but we opted to stay with the original plan and meet Alistair and the others before  getting a new more accurate location.

Meanwhile Ava/Cloud and Buzz rose as with their ascent rates very close to our targets.  Unfortunately though Buzz’s balloon burst at a distinctly unimpressive 27km, much below an average flight let alone an altitude attempt.  Worse, during descent it stopped transmitting so at that point I knew the payload was lost.  Ava/Cloud though continued to rise.  And rise. And rise.  Eventually they reached the #6 spot in the UK altitude table, not quite the highest for a photographic flight, but I believe it’s the highest carrying an external object (i.e. the Buzz toy).

South of Guildford Julie and I found a spot to park and wait for Anthony who was a few minutes behind us.  Checking the predictions and the map we then set a new destination south of Dorking.  I led using the LCD display to tell me where the payload was relative to our cars, whilst Julie checked on the prediction on her tablet.  As we got close to the expected landing point the payloads were just over a mile away and closing in.  We turned off the A24 to find somewhere as close as possible to the landing spot.  The road ended at a private drive next to a field, so Anthony and I jumped out to look up into the sky, then he spotted the parachute heading towards the trees nearby.  So we jumped back in our cars and tried to find a parking spot as close as we could.  From my LCD I saw that we were only 200 metres or so from the payloads, and a mere 300 metres where we parked.  The payloads were down by then and the signal from them still strong – a sure sign that they were not actually on the ground!  So we took the telescopic pole from our car, plus receivers and aerials, and set out on foot.  Anthony took his phone with him, running the car tracking app, so our path on foot was tracked online (bottom-left is where we watched the parachute from; top-right is our parking place; bottom-right is the path we walked to the payloads).

When we got to the landing area I spotted the chute at top of a tree:

Ava and cloud were both hanging below, with cloud looking to be almost within reach (but wasn’t as the ground was much lower below the tree than it was where we were standing). Buzz was above with the main support line going past him, so he’d been facing down during descent!

We soon decided that we needed more items from the cars to get these payloads down.  So Anthony and I headed back for scissors, line, duct tape and hooks.  Returning to the landing site we put a hook onto the telescopic pole, then pulled Cloud down to safety.

Ava though was too high to be pulled down, even with 2 of us pulling as hard as we could.  Ed’s knots performed amazingly well – it would have been a disaster if one had failed below either of the payloads. Ian tried climbing up a tree but that wasn’t enough either:

So instead Anthony tapes some scissors to the pole, added a string for “control”, and with Ava pulled as low as possible positioned the scissors thus:

So with both payloads recovered we set about checking our cameras.

With our payloads and cameras safely in our hands, we went back to the cars and headed into Dorking to find some food. Pub after pub had either stopped serving food that day, or hadn’t started yet, or their chef was off sick with food poisoning, but eventually we found an Indian restaurant that was about to open. “A pile of poppadoms and 9 pints of lager” sounded very tempting but some of us sadly had to drive afterwards! The food was very good and of course we had some photos and video to look at!

All in all, a great HAB day! Thanks go to all my helpers, but in particular my wife Julie for coming out despite being unwell, to Anthony for coming all the way down from Yorkshire with a large cylinder of hydrogen in his car, and Ed for tying such impressively strong knots! Here’s a taster of some of the images, but for more check these links:

My Flickr Set

Buzz Inflation Time Lapse Video

Buzz Lightyear Full Descent Video

Upwards Video

Time Lapse from Cloud’s Camera

The car PC installation was very useful for the balloon chase last weekend, but it would have been a lot better with a display closer to the driver’s line-of-sight. I knew that having the monitor buried down at the bottom of the dash wasn’t ideal, so I always expected to have to add a smaller display higher up, and here it is.

I was going to build my own controller, but found that thesell simple controllers that can connect to a PC using a USB-serial converter. So I bought one of their controllers and a display, and quickly got those soldered together and connected to a suitable USB converter.

After proving it all worked, I added some code to my car PC software to send important data – such as the balloon altitude and distance from car to balloon. The most useful thing when driving is to know the direction to the balloon, so this appears as a compass heading on the top-left of the display. Here’s the display temporarily stuck into a dash vent:

With the jet stream spoiling my plans for a latex balloon launch, I decided to try a foil balloon flight instead.  Latex balloons stretch with altitude, eventually bursting at roughly 100 times their volume at ground level, and typically at altitudes of 30km or more.  Foil balloons however do not stretch, so their altitude is limited to around 5km or so.  They do however offer a number of advantages – they’re cheaper, need a lot less Helium, and do not need a NOTAM assuming the entire assembly is always within 2m in any direction.  The latter means that the launch site can be decided on the day (though not anywhere can be used – you still have to avoid launching into a restricted area for example).

For the tracker I opted to use one that I dunked in the English Channel in my last flight.  The tracker in my larger payload (Cloud3) was did not survive, but the one from my smaller payload (Buzz3) did.  I didn’t want to use that on an important flight so it was ideal to use (and probably lose) on this.

So I tidied up that tracker (removing deposits from the salt water) and made a simple container from sheets of foam polystyrene:

With the batteries connected and the payload closed up, I inflated the 2 foil balloons and adjusted so they gave the same amount of lift (measured by tying down to a small weight on sensitive scales). Then they were tied together, attached to the payload and taken down to the launch site.

Originally I planned to launch from a high point (on the Ridgeway) but the wind seemed gentle enough to launch from the village green. Big mistake. We took the balloon there, checked for the wind direction and then took the balloon to a far corner to give it plenty of space to fly into. However the wind change direction for the launch, and the balloons went up then down again a little before swinging back up again near the trees. It was a close thing, with the payload just escaping from one branch before tangling on the next:

Well, I’m not the first to launch a foil balloon payload straight into a tree (easy to do as they rise very slowly compared to a Latex balloon), and I wasn’t concerned about the loss of a salt-damaged tracker, but even so I was pretty dejected when I returned home.

Well, there’s only one thing to do after a failure, and that’s to replace it with a success.  So after some deliberation I decided to use my tiny “egg” payload and launch with 2 more foil balloons.  It was likely I would lose it, but I could just make another for next week’s latex launch.  The payload was ready and just needed the batteries connected and the two halves of the container glued shut.  So with that done, two more balloons inflated and tied to the new payload, we drove off to the original launch site.

We checked for the wind direction and then made sure we found a spot with no chance of hitting either of the trees!  Here’s PicoBuzz1 (B) heading off on his journey:

Foil balloons don’t get up into the jet stream, so don’t generally travel fast. So we had plenty of time to follow the balloon around at a leisurely pace, trying out my car PC software for real for the first time:

After the first stop we looked at the projected path and decided to go to Goring by the Thames, near where we believed the balloon would go. As we parked up we could see on the live map that the balloon was approaching, and it got to within 150 metres of our position (but 6000m up!). Too far to see, even with binoculars. Anyway, we had a pleasant hour in Goring:

AFter following the balloon around for a while, it settled into a float so we headed home for food and to track from there. However by the time we got there, one of the 2 foil balloons burst so it started to head down to the ground. So we headed out again, armed with warmer clothing, a Yagi aerial for direction-finding, and a couple of large torches. We were quite close to the balloon when it landed and we lost the signal. With no internet we were struggling to get decent mapping, but eventually we found some roads closer to where we believed the payload to be. Once we got to the area the rtty signal started coming in, weak at first and then strong enough to decode, so now we had an accurate position to aim for. He we are on the map trying to get closer to the payload.

The Sat Nav got us close, then we parked up and set out on foot, but before a passing police 4×4 and later a security guard asked what we were up to! I guess we worried the locals! Here’s the gate next to where we parked:

A short trek later and we found the payload and balloons:

Here’s the full path:

and the hole in the balloon:

I’ve added a new page to the technical section, showing the car PC software I will use on the next launch.

This is the build of my latest photographic payload carrying, as usual, a Canon compact camera and a Kodak HD Video Camera. At less than 700g it’s my lightest yet with this configuration.

The tracker has UHF telemetry as usual, plus an SMS backup.

To help get the weight down, I made the box as small as I could whilst still holding the cameras and trackers, and still providing enough insulation and protection. I cut the pieces from 25mm and 500mm sheet polystyrene foam using a table-top foam cutter (makes it a lot easier to get a neat finish). Here’s the base piece which carries the aerial, 4-wire ground plane and radio transmitter:

The radio transmitter is the usual NTX2 model, and here’s a close-up showing the aerial connections on the left and the signal/power connections on the right.

The tracker electronics go into the lid, shown here up-side down. This was made in 3 layers of foam, the bottom layer being for protection and also holding the GPS antenna and the piezo buzzer. On top of that goes a second layer cut into compartments for (clockwise from bottom-left) GSM module, batteries, flight computer, GPS receiver and a level converter for the SMS module. Finally, a thin layer of high-density foam goes on top to hold everything in. That has a hole for the battery compartment and a flap over the compuetr compartment (to allow for firmware updates).

Here’s the completed lid with tracker, next to the main payload box with antenna base underneath. All the foam has been covered in duct tape for strength and protection.

The cameras go inside the main compartment. As on my previous large payload I have put the cameras inside carriers to hold them firmly and stop them slipping during flight. Main camera is a Canon A490 which is programmed to take 1 shot every 5 seconds, plus there’s a Kodak Zx1 HD camcorder with external batteries to extend its recording time. Both cameras will run for at least 5 hours – more than enough for any normal flight.

These carriers fit into the main compartment like so:

and then have small lids added to stop any vertical movement.

Finally, here’s the completed payload, weighing 667g including batteries:

This is the build of my smallest and lightest payload yet, using the tracker that I made recently. First job was to solder 3 Lithium Energizer AAA cells together and strap them to the tracker:

I deliberately placed the cells next to the radio transmitter, and put some hot-melt glue in there, to stablize temperature-related drift of the transmitted frequency.

Next, the insulation. This is pretty minimal, intentionally to keep the weight down. This will mean that the electronics will get quite cold, but not as cold as on Buzz1. I’m expecting the radio frequency to drift more than usual as a result, but again not as bad as on Buzz1.

The flight may well not be till Easter (depends on the wind predictions) so I chose a suitable theme. Here’s Buzz holding the shell …

First job, crack the egg open. Larger ones come in 2 hollow parts but this one is solid with a weld which I cut through:

After gouging out the innards to hold the tracker, and painting the outside in a natty shade of pink …

… I soldered the 1/4 wave antenna to the tracker and inserted into the top half of the egg:

And here’s the final result, weighing a mere 42g. As a reference, you would need about 24 of these to weigh the same as my first payload! With ‘chute and line, it will be about 50g total for the balloon to lift.

By far the largest and heaviest component on my previous tracker was the FSA03 GPS receiver, and most of that was the Sarantel antenna. That antenna is amazingly good (it picks up a signal on my desk where there’s very little direct view of the sky), but it is heavy. So having received a new GPS module from HAB Supplies with a tiny and very lightweight antenna, I was keen to try it out. The module weighs about 1.5g and is slightly smaller than the Arduino Mini Pro I use for my flight computers. That tiny white rectangle at the front is the antenna!

So first job was to connect these two up, then load some firmware to confirm the GPS is working:

Unsurprisingly, the antenna isn’t as sensitive as the helical Sarantel one. That’s not a problem for weather balloon flights though, as they have a full view of the sky.

I then added the usual set of RFM22B transmitter, BMP085 pressure/temperature sensor, and DS18B20 temperature sensor on a short lead (for measuring the temperature outside the payload). So here’s the final tracker, just needing batteries, antenna and some insulation:

Total weight of this tracker is a mere 7.5 grams (that’s less than the GPS receiver/antenna on my previous tracker!).

To test I programmed the Arduino with the software for my previous small tracker, modified slightly to use a different modulation method and to run at 6 times the speed (300 baud rather than 50). It worked fine using my Yaesu FT790R as a receiver:

I plan to fly this tracker on my next flight at the end of March.

The GPS used for this tracker can be purchased from HAB Supplies. Other parts came from Proto-Pic.