UpLift-1 Takeoff 28th Dec 2011.
Before we even left home we needed a massive list to make sure that we did not leave anything behind. After all, a 600km / 400 mile trip for nothing would not be a lot of fun. It was a huge list for such a small balloon and payload. It included the balloon, parachute, payload, helium, spare balloon, test equipment, hoses, cameras, tripod, 2-way radios, tracking radios, decoders, computer, USB cables, mobile phones, car chargers and much, much more. But this is not about that story, this is launch day! We traveled to West Wyalong in NSW (Australia) and spent the night in a great little hotel ready for an early morning departure. We still had 100km / 60 miles to drive to the launch site. The first thing was to check the weather. We had already looked at a long distance forecast before setting the date as the Civil Aviation Safety Authority (CASA) in Australia have to issue an alert to pilots for our balloon. CASA have been wonderful and amazingly helpful. A peek out the door reveals a perfect day for a balloon flight. The photo on right shot outside my hotel room reveals a brilliant day with little wind early in the morning. We packed the car and headed to Rankins Springs near Goolgowi. I had fallen in love with this little town in the middle of nowhere. With about 50 people living in town, it was just a speck on the map at the intersecting of some sealed main roads. What struck me was that it was a place that people cared about. The public places were clean and the grass cut, perfect for preparing a balloon flight.
We found a clear grassed area next to an old Railway water tank used for filling steam engines. The contrast was great – the old and the new. This story is going to be a bit instructive so lots and lots of pictures. First I had my son Jason (9) laid out the clean plastic sheet for the filling operation. We placed items in the corner in case a breeze kicked up the corners and destroyed the balloon. We also used Latex gloves to stop acids and other oils from transferring from our hands to the balloon and potentially causing an early failure of the balloon when the UV and other chemicals in the air act on it. We could also have used clean cotton gloves. The problem there was two fold. Sweat from our hands filled the gloves and needed to be changed occasionally to prevent and drops from landing on the balloon. The second problem was that every time we wanted to use duct tape, our gloves stuck very well to the tape! That is me on the left taping the hose to the balloon to protect it and getting the gloves stuck to the tape. There were cable ties under the tape and I used the tape to protect the balloon from sharp edges. The cable ties held the balloon to the flexible PVC tube. I also had the other end of the tube over the balloon fill regulator on the helium tank. That was just sealed with duct tape.
It was then time to prepare the payload. I had decided to block off one of the port holes for the video camera as I wanted this balloon to rise quickly. I was also going to overfill the balloon above specifications to ensure that it would explode a bit earlier than normal. All precautions for a first flight. While we were preparing for the flight, Wally, one of the locals came by on his ride-on mower and remembered me calling in at the petrol / gas station a month earlier. He was excited that we had chosen his town for the launch and went off to find the kids in town so that they could join in with all the excitement. Wally was the unofficial “mayor” of the town! A lovely character that obviously cared about kids. The photo on the right shows me preparing the GPS transmitter (Amateur Radio APRS). I am wrapping it in bubble wrap as a thermal insulator to protect it from the cold at the outside air temperature at times during the flight will be between -40 (-40F) and -50C (-58F) or possibly even lower. The capsule is also made from Polystyrene so that too will provide some protection from the cold, but with openings for the camera, there will be some cold air entering the capsule. Care was taken to ensure the dipole antenna (the two gold wires) was mounted vertically in the capsule in the correct place and the small GPS receiver was on top so that it would get a strong signal from the GPS satellites orbiting the earth. The balloon was on a 10m (30ft) cord so that the antenna had no chance of puncturing the balloon. The final benefit was that the capsule would never land upside down so the GPS receiver would always be able to receive satellite signals and report its position once on the ground. Lots to consider. The batteries were also the best that we could buy. Failure was not an option and the cold can kill batteries. We also wanted the transmitter to last for as long as it took to recover the balloon. The unit was switched on and the receiver in my car was used to checked it was operational and all systems working. The unit reported position, altitude, atmospheric pressure, payload temperature and battery voltage. All parameters where checked and normal. APRS normally will allow you to see the track on the Internet, but we were too far away from any receivers to register. That would only happen when the flight was high enough for the distant receivers to “see” the balloon – once it was high enough to overcome the radio shadow caused by the curvature of the earth, allowing “line of sight” radio signals to be heard. Similarly when we landed, we would lose the signal close to the ground. We were going to rely on the receiver in our car to pick up the transmitter signals and read the location. This would be super important in a couple of hour. More on that later. The photo at right show the transmitter with one layer of bubble wrap. Two more were added with the GPS receiver wrapped to the top – above the side that you can see the unit with care taken to get it the right way around.
The camera batteries were charged the night before and the camera then required special care. We had it in a sealed box with desiccant overnight to ensure that there was as little moisture as possible in the camera. This would otherwise cause condensation during the flight and fog the images. It was inserted quickly into the housing and the almost closed housing was flushed with helium from the filler hose. This ensured that water in the air was removed and the housing was sealed. The camera was turned on and set to commence taking photographs – the counter on the front began incrementing every 30 seconds. Both the camera and the transmitter were mounted in the capsule. The picture shows the camera in place secured with blocks of polystyrene and the transmitter in place with the GPS receiver at the top. The payload bay was covered and sealed with duct tape and the capsule was ready to fly. All that waited was to fill the balloon.
We had brought a large bed sheet to hold over the balloon in case the wind was too strong for a simple fill. The wind was light and we did not need this, but if we had we would have asked volunteers to hold each corner down while we filled the balloon. The balloon fill was simple, but we needed to measure the diameter to get the fill right. If we under filled the balloon then it might never burst or even rise fast enough and drift long distances before popping. Either way I had made a decision to lighten the payload by leaving out the video camera and to overfill the balloon slightly. It was, from the manufacturer’s specifications meant to be 1.2m (3.937ft) in diameter. I was going to fill it to 1.35m (4.43ft). Since the day was sunny, it was easy to accurately measure the diameter. We simply used a tape measure across the centre of the shadow – perpendicular to the rising sun. This meant that any stretch of the shadow from the angle of the sun would not affect the measurement. In the picture at left you can see that the sun is behind me and Jason is in the right place. The local that was helping just needed to move the measure up closer to the camera to get the final measurement (the photo was a few seconds early). We had the right diameter now and were ready to remove the hose and secure the payload. The helium tank valve needs to be shut off at this point in case the hose gets pulled and the tank either topples or adds more helium to the balloon. If the tank falls, then you could damage the regulator.
This next operation was the most difficult part of the procedure. We had already wrapped a cable tie in duct tape to lower the chance of tearing the balloon when inserted. it would secure the nylon cord that secures the parachute and payload. First though, we needed to cut away the cable ties securing the balloon to the hose – all without cutting the balloon. The protective duct tape was peeled away and side cutters were used to sever the heads of the cable ties. This kept sharp edges away from the balloon. That is me on the right cutting the cable ties away (sorry no close-ups). Once the hose is removed then the balloon needs to be sealed and secured. I have no photos of this but the fill tube of the balloon is folded once and then a second time (4 folds thick). The cable tie with duct tape that was prepared earlier was inserted in the middle of the bottom folds ready to secure the payload. I then secured the balloon and and its gas with three cable ties above that making them tight around the fill tube. It must be tight to keep the gas in during the flight, especially as the outside pressure gets down to a few percent of sea level and the inside pressure remains the same. I cut the loose ends of the cable ties and used duct tape to keep them from touching the balloon. The cable tie that secured the payload was looped and the payload tied to the balloon. Again duct tape was used to secure the knot holding the payload to the balloon. Nothing was left to chance. The knot used was a bowline and few half hitches – sufficient if you have the duct tape to stop them unraveling. We were ready to launch. The local mission control countdown team were assembled (all but one shy kid and a few adults) and provided the all essential countdown – that’s Wally in he green/yellow safety shirt.
It was a great moment. Rankins Springs’ first near space mission. The countdown proceeded with the kids leading the chant. At zero, my son Jason released the balloon and it was away. Note the old steam engine water tank behind Jason – the old and the new. At about 270 metres the distant APRS receivers saw the balloon’s transmissions and we breathed a sigh of relief that we would be able to track and recover the balloon. We saw the updates every 20 seconds on our smart phones with all the details of the flight. We watched as the balloon stayed in clear view right up to 5km. We kept losing site of the tiny white dot, but the odd reflective glint from the shiny black duct tape brought our eyes back to the tiny 1.35m (4.5ft) white dot up in the clear blue skies of central NSW. It should be noted, that none of these photos have been altered. They are directly from a number of cameras. The colours have not been corrected! The final job was to pack the car and chase the balloon.
It was serendipity that the first photo snapped by the payload camera at around 270m (900ft) was of the town itself. A wonderful memento of the occasion.
Below is the photo from Rankins Springs. You can click on most of the photos above and below to see a large version of the image (requires that you click through an intermediate page). I have uploaded the image of the town in the highest format possible.
60 seconds after release (below). This photo looking east above Rankins Springs: