by Robert Brand. It is not something that we think about too often, but contemporary artists David Haines and Joyce Hinterding certainly have been wondering about it – sound – a lot. What passive sounds can a payload make when moving through the air? They have chosen to do an installation in Australia and France about releasing a balloon into the stratosphere and exploring sound during the different stages of flight.
They have an upcoming exhibition opening at the Powerhouse Museum and at Parramatta in Sydney and I believe, later in France. We will be at the Powerhouse Museum for their opening night. Their details can be found at their website pages:
We have all heard the sound of the wind in recordings, but this art piece will record special sounds made by bows and strings vibrating in the wind. There were three instruments, each set to make a different pitched sound in three different planes.
A Sound Idea
They approached our balloon company, HABworx, recently to see about buying a weather balloon and doing the flight themselves. When they found out the task that they faced, they brought my son Jason and me on board to help with the technical aspects of the flight. They would concentrate of the sound aspects of the payload I met them last weekend and found out that there was a video being made of the entire workup to the flight and their friends from France would head home shortly. So one week out they hired us to make it all happen. Making Art and Sound would go into the Stratosphere
We ordered the helium, checked the electronics and arranged a NOTAM (NOtice To AirMen). A bit sexist these days, but that it what it is called. It is issued by Australia’s Civil Aviation Safety Authority (CASA) as I have already been approved to fly certain sized payloads to the Stratosphere – up to 4Kg. It took weeks and a lot of work on the risk assessment – 3 attempts at getting it right. We packed the car and met them at West Wyalong ready for the one hour trip to Rankin Springs in central NSW. The next morning we left separately after getting breakfast at the local bakery. We arrived at 8am. The rest of the team arrived nearly an hour later as they had to return to West Wyalong for fuel. They had forgotten to fill up their vehicle fuel tanks. There is nothing out there and small town fuel stations are often closed on weekends.
16-07-2016. It is winter in Australia and there had been a lot of rain over the last month. We normally launch in a reddish dirt field, but on launch day (yesterday at time of publication), it was a lush green and the small town even had to mow it in Winter. There was a frost on most of the field still in shadow, but it was warm in the sun. We set up our gear and waited for the team to arrive.
We basically started at 9am, but their was one more wrinkle to iron out. I got a phone call from Rex Airlines operations. They had a flight from Sydney to Griffith and the pilot had asked that we don’t release the balloon between 10:45am and 11:30am local time. We agreed and so we had a 1.5 hour deadline or we may have to wait until 11:30am and that may be with a filled balloon if we were in the middle of a “fill” when we ran out of time.
I left the customer to prepare their payload, their sound instruments and sound recording and their spot tracker. I have an agreement with all flights that we have an amateur radio payload of 300 grams and usually carry an APRS transmitter and some other instruments as part of the deal. It is amazing how many HAM radio operators and others follow the flights on the APRS tracking website.
At 10:25am the payload was complete and ready for flight so they gave me the OK to fill the balloon. That takes about 15 minutes as we like to use a standard party balloon regulator. We know that we can get a faster fill with a gauge regulator, but that is not a bog consideration and can cause trouble with extreme cold air in the neck of the balloon – especially in winter. I have no idea whether this affects the balloon, but I did not want to risk a problem. We used our special fill and seal system. It is a tube where the balloon and payload are already connected and after the fill, you just screw on a cap and release the balloon. You don’t need lots of people holding the balloon and there is no fear of last minute hassles securing the neck and payload. Simplicity and ease are how I would describe this light weight accessory.
At 10;42 the balloon was filled and released in about a minute. We rang Rex Airlines and gave operations the news that we were in the air.
A Sound Flight
This is an unusual day to day the least – first request from an airline to delay a release and to be very clear, our flight was 100Km to the north of their flight path. A rather unusual request given that their altitude would be only about 6Km in my area at the most and by the time we intersected their flight path on a windy jet stream day we would be at 20Km. It worries me that we might get these requests regularly. Although the flight path can be way off the predictions, at the area of release, it is relatively accurate. As the flight time increases, the total error increases. Today we would find out that the winds were stronger than predicted. It went in the predicted direction, but traveled further due to stronger winds in the stratosphere. They got to 150kph – that is 93mph for those in the antiquated non metric systems! They were expected to be only be about 60kph maximum. At the time of the NOTAM it was only meant to travel about 50km from the release point. On the day the prediction was saying 90km and it turned out to be 130km travel. This was despite a slight overfill to ensure a good climb rate. We like about 6m/s. the direction of travel remain about the same.
As for the Rex Airlines request, we honoured it, but we believe that they did not know that we were very experienced and could be trusted. There is no technical course to take when you decide to send a balloon to the stratosphere. You have to submit a risk assessment that is fairly tough and a “flight plan” that is really a prediction and may vary greatly as I said. I will talk to CASA today and see what I need to do in such situations. That is, when Rex Airlines asks for something that worries them on the day. To be fair – it was only the pilot of one flight – not everyone in the airline, but it was still a request from operations. If we had enough requests from pilots, then we would be stopped from flying totally. That would be an enormous amount of money to waste in this case. We had 4 vehicles and 9 people that had all traveled from Sydney for this release. 6 hotel rooms and the fact that the video people were returning to France would have been a serious blow to the whole event. I will discuss this with our Civil Aviation Safety Authority (CASA) today and also Rex Airlines and I will report on the outcome.
The next unusual thing was that the balloon went west with the winds in the low troposphere – ground winds and lower level winds and then as the jet stream took over it came back over head. This was predicted. We set a new personal record for being able to see the 3m balloon with the naked eye. 11.1km altitude right overhead. That is 6.9 miles to be able to clearly see a 9 foot white object. Amazing! Not just one person, but several with good eyesight. The incredible clear Australian winter skies and the fact that it remained overhead to that altitude was a lot to do with it of course, but I would never have thought that it was possible. Previous best was 5km altitude. I doubt that we could top this because the conditions were perfect and the balloon was a pinprick of white in a bright blue sky. Polaroid glasses may have darkened the sky to help more, but the resolution of the tiny dot was probably at optical limits for everyone.
We will need to replace our APRS transmitters because the transmitter is definitely failing. We thought it was cold from not insulating it well enough last time, but it also appears to be low power and some sort of distortion is still there at the slightest hint of cold. Last time it stopped working when exposed directly to the jet stream conditions. This time it transmitted consistently, but with large gaps all through the flight. Our ham radio had a lot of trouble picking up the signal and decoding it. This was only the start of the problems.
We tracked the payload and we were getting odd data and even set a new second personal best – an altitude of 33.668m or 20.920 miles or 110,459 feet. To be clear, we are never trying to break records. This was a 1.2Kg balloon with a 2Kg payload. Nothing special. One day we might try to see what altitude we can reach, but it will be a special flight and we might not try to recover the tracker. we would use more fuel than the tracker is worth. We need to declare that in advance so you don’t think that we lost a payload! It may be a nice job to send our dodgy tracker on a farewell flight and see if we can heat the tracker to keep it active and send it on its way. Sounds like a plan.
A Not so Sound Descent
The next problem was clear when we later saw the video that we recovered. The balloon exploded and a piece if balloon fouled the bottom of the parachute sealing the cords together and stopping the parachute from opening. The second issue was that the cord to the parachute twisted around the payload placing it on its side – even slightly upside down. The spinning slightly inverted payload mean that the SPOT 3 either never got GPS lock or could not get a good signal to the relay satellite. It also landed upside down and when we found it it also seemed to have turned itself of. It was useless. Our primary tracker was gone and we had a partially working APRS tracker. We headed past West Wyalong and to the road to Grenfell where it had given its last report at 5km altitude.
We had a search on our hands over a wide area. We did however have a little luck on our side. As we drove past the location that we last got a decodeable transmission from the APRS unit, we heard a faint burst of noise in the receiver. That was the APRS transmitter still working with its antenna on the ground. The search area narrowed and with a tiny bit of deduction, I turned off the road and moved 50 metres closer to the downed payload and I got a decodeable burst of data. Not only that my radio digipeated to to an iGate (HAM radio talk) 240Km away and we had a fix on maps on the Internet. It was 200m / 660 feet to the north of the road. We placed our horse blanket over the barbed wire fence and walked without compass in the direction of the payload. Jason spotted it first and even though it hit hard, everything was working fine. Even the sound instruments were undamaged.
Everyone was ecstatic and the video is truly amazing – we had a look at some of it in a little coffee shop in Grenfell. I expect that we will be assisting this team when they next need to fly. Again, this is another case of only having a partial track, but experience and a good radio ability is key to success. Before we left the landing field my son Jason (14) and I had our traditional toast to another success. It is some of the best ginger beer on the planet that is non-alcoholic. Bundaburg Ginger Beer – it is a soft drink / soda. Balloon release 28 and recovery 28. Our 100% success rate remains intact. It was a very nice drive home on a natural “high” – 33.668m high!
Videos later. More on the sound made by the passive “musical” instruments in the video post – they worked and you will hear them. Not so musical, but more like a buzz saw!