With the Global Space Balloon Challenge, a lot of emphasis in the media has been placed on how easy it is to conduct a high altitude balloon flight. This article seeks to redress the balance by pointing out how easily a HAB flight can go wrong, using the experience of actual HAB flights.
1. Bad weather. As with other pass times that use the skies, weather is the main reason why planned HAB flights never leave the ground. Rain, snow, poor visibility, freezing temperatures, and windy conditions will all lead to the cancellation of HAB flights. For those who try and brave high winds, they risk underinflating the balloon as turbulent winds give a false impression of balloon buoyancy.
SOLUTIONS: In high winds take any opportunity to fill the balloon in an enclosed space such as a hanger or barn.
2. No / poor flight plan. Planning a flight, so that operators have a clear idea where their payload may go, is key to a successful mission. Conversely, when flights are not planned then failure can happen. Last year, in BOWLING GREEN, Ky. (WBKO), two independent filmmakers had to ask for the public’s help to find their missing weather balloon.
Jacob Adams and Galen Olmsted launched the balloon from Preston Miller Park. Their GPS tracking system failed. “Yeah. It was about $120 per camera. There were three cameras and yeah I would say the whole thing cost me about $800. So the next launch would cost me around 400 or 500. I wouldn’t have as many cameras,” says Jacob Adams. Adams said, who did not forecast the balloons flight path said “ The balloon could have traveled anywhere from 40 to 250 miles away.” If Jacob had a flight plan with forecast, then me may have had some idea about where to look for his payload.
SOLUTIONS: Plan your flight. Online forecast software is available from CUSF and Wyoming University. CUSF also offer an online burst calculator which provides a great guide; but only a guide.
3. Under inflating your balloon. If you don’t have a clear grasp about how much gas your balloon needs to achieve the desired ascent rate then you will most likely under inflate or over inflate the balloon. In my first flight, I inadvertently achieved a very low ascent rate. As a result, the flight from Welshpool that should have only gone east of Shrewsbury, went to the Netherlands. Similarly in 2014 a team from Nottingham University Physics society lots their payload out to see as the balloon was under inflated. Their situation was compounded by loosing a tracking signal from their radio beacon. Their payload was eventually recovered when it washed up on a beach but the camera equipment was ruined.
Even when you have a good grasp of the gas fill you need and how much you think you have put in, things can still go wrong. If your gas cylinder has not been pressurised with the correct amount of gas ad you fail to check the amount of lift the fill gives then you will release an underinflated balloon. Both Adam Cudworth of the UK (http://habe.acudworth.co.uk/blog/) and John Flaig of Wisconsin, USA (http://www.nearspaceballooning.com/) have had HAB flights that have gone on much longer than expected due to the insufficient pressurisation of their helium cylinders.
SOLUTION: UKHAS provide many useful wikis to balloon inflation. CUSF burst calculator will also give you a guide to the lift provided by your balloon. Make sure you double check the lift provided by your balloon.
4. Early balloon failure. When you plan your high altitude balloon flight, optimism focuses you on your forecast balloon burst height. But balloons can burst much earlier than expected. This may be due to a manufacturers defect or icing on the balloon. This can radically change the landing site and your plans for recovering the payload. In September 2013 I launched a 1600gm balloon for an Irish advertising company from Aberystwyth, Wales. The balloon burst about half way into it’s forecast ascent. This meant that I had to recover the balloon in an area of upland forestry, not lowland pasture as planned. As I had my young children with me, recovery had to be left to the next day and my helpful father.
SOLUTION: It is hard to detect imperfections in a balloon that were made during manufacture. There are some things that can shorten the life of a balloon after inflation. Leaving an inflated balloon to stand for some time can lead to premature failure.
5. Parachute failure. When your parachute fails, your payload will plummet to the ground. This will not only endanger your equipment but also people on the ground. John Flaig launched a HAB flight in July 2013 in which the parachute became from it’s parachute.
John explained the cause of the parachute loss, “I had used a thinner walled styrofoam box for this launch. As it turned out the violent spinning and flipping that occurs when the balloon explodes proved too much. The chute yanked from its mooring, the payload plummeted unencumbered from 105,000 feet, falling at hundreds of miles an hour before slowing in the lower atmosphere and smacking the ground. The bottom of the box was crushed, the external GoPro battery sticking out of a hole, another camera lens cracked. Inside, everything had more or less held, including, thankfully, the gimbal keeping the Spot GPS facing up.”
SOLUTION: Ensure that the parachute is safely secured to the payload. Use a parachute from a reputable manufacturer. Choose a parachute with the least number of shroud lines.
6. Damage to the payload / damage by the payload. An article by the Daily Telegraph in 2010 revealed that the Met Office had paid out more than £25,000 in compensation since 2007 for damage caused by it’s radiosonde programme. The article,
sighted damage caused to conservatories, car windscreens, and power lines. Our own Freedom of information request to the Met Office showed that for 2010 to 2014, the figure for insurance claims was much less than the figure quoted by the Telegraph. In this time they had had a small number of low level claims relating to matters such as, the retrieval of sonde balloons caught in trees (various), one caught on a power line (2010), one case of damage to a roof tile (2011) and one case of ingestion by farm livestock(2012). The maximum cost of these claims was £200.
In the world of amateur HAB information on damage to things on the ground is harder to come by. I have come across stories of payload boxes landing on roads and being hit by cars. There was also an instance in 2009 when a Met Office Radiosonde ‘crashed through a perspex roof in a school building and startled the staff and children.
Information on damage caused by people trying to recover their payloads is scarce. I have come across stories of people lawfully paying to fell trees to recover their payload. In September 2013 I hired a set of trackers to Ian who launched a balloon from the south coast in the UK. The balloon landed in a conifer wood on the edge of RAF Mildenhall in Suffolk. A local land owner helped Ian by felling the tree to recover the balloon. This wasn’t great for the tree involved but the cumulative damage to the number of trees in the world caused by HAB flights cannot be that great.
7. Camera failure. Common among many HABists is the desire to see the view from ‘up high’ and HAB flights commonly carry cameras. Action cameras were one of the main driving forces in the rise in popularity of HAB. With every new iteration of the Go Pro Hero (other action cameras are available though invariably not as good) the performance of the cameras in HAB flights has improved. But cameras still fail to perform throughout the flight. They are also more or less certainly going to be subject to fogging if the lens is covered by a sealed case of some kind with air containing moisture. Icing on the camera lens has a similar effect. If the balloon operator fails to recognise this then they will fail to get the photos they want.
SOLUTION: Keep the camera out of sealed cases, however, you then run the risk of damage to the camera on landing.
8. Tracker / locator failure. Whether you have bought, hired, or made your own tracker, it is prone to failure. Accepting that fact, you will hopefully have a back up system. If you don’t, and your tracker fails, then often your payload is as good as lost. Tracker failure can be electronic. A frozen battery and electronic interference caused Nicholas Janzen’s home built radio tracker to fail.
Tracker failure doesn’t have to be electronic though. It can just fail due to operator error. Last year Emily Dawson, a grade school science teacher from Illinois launched a HAb as part of a science festival for her school.
The payload of the flight included an action camera, flight computer to record climate data, and a SPOT Messenger for tracking the payload. Emily said, “The plan for recovery and tracking was to use SPOT….but something happened between turning it on and lift off. The SPOT was tracking for almost thirty minutes. We believe we launched around
10:56…the last time the SPOT communicated. It either got bumped during the launch or it was accidentally turned off prior to being taped into the payload box. As luck would have it an extensive search along the balloon’s forecast flight path lead to the balloon being discovered. It was found in a farmers field close to the road side.
When your tracker or locator does not suit the environment that you are using it in, then expect it to fail. If you use a GMS locator in an area without mobile phone coverage then it will not tell you where your payload has landed. Similarly, if your radio tracker lands in hilly terrain then the signal will not get out for listeners to receive. Or if you operate it at a time of day when no one is listening then nobody will record the tracker location.
Finally your tracker failure may just be down to bad luck. If your SPOT tracker lands face down then more often than not it will not return your payload landing site.
SOLUTION: On radio trackers, extensive testing can weed out many of the hardware problems. Combining a the radio tracker with a PLB also ensures the operator against failure.
9. Payload landing in inaccessible places. Up a tree, in a lake, on a mountain, on top of building, in power lines, and on MOD property. The list of possibilities is endless. While we can plan to avoid large hazards like a whole forest or town, you cannot plan to avoid smaller hazards like smaller woods or individual pylon towers. If we don’t plan our balloon flight well then the worst often happens. Most sea landings fall into this category. Sometimes sheer bad luck means that the payload lands in an inaccessible place.
SOLUTION: There is no real solution to this but being prepared for tree landings will help you if it happens.
10. Stolen payload. Balloon News has reported on many heart-warming stories about HAB payloads that get lost by the flight team, only to be found and returned to them by members of the public. It is true, however, that some people think that just because they find a HAB payload then it belongs to them. With the rise in value of cameras deployed in payloads, the temptation to steel the payloads has increased. Even when expensive cameras are not used, payloads have been known to be taken.
I first reported on HAB theft last summer, on a case in Leicestershire. The report was made by the Group Scout Leader of the 63rd Leicester Scout Group in Leicester. The group finished and end of term celebration by launching a weather balloon which the scouts had been working on.
The weather balloon was carrying a white polystyrene box (approx 30 cm wide x 20 cm deep x 25 cm high) containing a brand new Philips ESee CAM150RD video camera, a GPS tracker, a battery and a 63rd Leicester Group scarf (maroon with yellow and purple edging strips) which had been
signed by all of the children at our Group. The box was secured with heavy duty black plastic ties. When the balloon burst, an orange & green parachute controlled the box’s descent. The group tracked the descent and landing to a farmer’s field bordering on the canal close to where you are (North side of canal on Home Farm about 500m North of Hillmorton Locks). As it was getting dark the scout group didn’t come to collect the box until the morning after it’s launch. The box was found the following day, but the lid was
missing as were the plastic ties. The base of the box was undamaged but only the tracking device and battery remained. Most importantly, the video camera, Scouting scarf and parachute were also missing. The surrounding area was searched thoroughly but nothing else was found.
SOLUTION: It is hard to stop the opportunist thief but the risk of theft can be reduced if you get to the landing site soon after landing. Working in a team with one group at the drop zone may help.
This is by no means an exhaustive list. But it does highlight that HAB flights can go wrong for a range of reasons. Some of these are within the control of the operator and some outside their control.
Comments added from UKHAS message board https://groups.google.com/forum/#!topic/ukhas/K-4zi2o5KwU
“Tracker failure” is a whole encyclopedia of fails all on its own, starting with “being unfit for purpose” which definitely includes GSM trackers and to a lesser extent SPOT trackers. Then you’ve got coding errors, physical problems (aerials falling off, batteries coming lose, single-core wires breaking).I’m not aware of any parachute failures, and I really hope that’s not happened. Shouldn’t be possible with an inline chute. They can get tied up a bit by the balloon but they do still work.