LDBinfo

LVL1 Amateur Balloon Distance Record Breaking Proposal

By Dan Bowen

The crossing of the Atlantic Ocean, and landing on foreign soil, with an amateur small balloon remains to be achieved. A group came extremely close 3 years ago, within 300 miles of the coast of Europe, but splashed down in the ocean. They proved that it can be done - and they have posted all their data and knowledge online for others to build on. Are we the ones who will do it?

I was the leader of the most successful amateur balloon series to date - the Spirit of Knoxville, which was the closest so far to grabbing the flag of landing in Europe. We will be able to save a large amount of time by using the lessons learned from the prior group. It took them 3 years. I think we can do it in 6 months.

There is another team from Toronto trying to do the same this winter - so keep in mind that we'll be in a race. Since we're tech-oriented here, I'll put the background info at the end, and get right to the challenges.

The challenges are many

• Stopping the climb - A special vented polyethylene plastic balloon design must be used, there's a small company who has the equipment to make them custom for the trans-atlantic crossing. making them is difficult to get right, but not impossible.
• The law - US FAA law requires imposes many limitations, but the most challenging one is this - two 6 lb containers are the maximum weight and distribution you can carry under the balloon.
• Solar heating - The sun turns a balloon into a greenhouse, making it into a partial hot-air balloon. More lift in the daytime, lots less in the night. Not good if you're trying to stay at a certain altitude
• Heaving ballast - much weight must be jettisoned at EVERY sunset to stay at the same altitude. The cold also affects the choice of ballast release mechanism
• Telemetry - 2000 miles from land isn't an easy place to get data from, and even harder to get commands from the ground to the balloon.
• Temperature - it's a cool -40C in the daytime, and a chilly -70C at night. Nothing works like you'd expect it to when that cold. You must cryotest everything before flying
• Power - you've got to carry a lot of battery power with you - and batteries that can operate super cold are few and far between Energizer e2 lithium are likely candidates. The weight of solar panels and aiming mechanics usually outweigh the benefit.
• Software - Software needs to manage ballast, telemetry, and also make decisions based on latitude and longitude boundaries - some countries don't allow certain radio transmissions from balloons.
• Electronics hardware - cheap, lightweight, low power, small size
• GPS - must be verified to work at high altitudes - many gps models have an artificial altitude threshold they will stop working above.
• Cost - typically each flight attempt will cost $400-$500
• Quantity - Many (4 to 8) attempts will have to be made before the weather and our luck coincide, and nearly every flight that fails will never be recovered - don't expect to re-use any hardware.
• Weather - the only way to cross the ocean is to ride the Jet Stream. Special balloon flight forecasting software must be set up to warn us when the Jet Stream is travelling from here to the other side of the pond. This will only happen about 8 times during the whole year.

High Altitude Balloons in general

High altitude weather balloons are large latex or plastic balloons that carry instruments and experiments into the upper atmosphere. A typical simple balloon will be 4 feet in diameter, white latex, and carry 2lbs of payload. It will climb at 1000 feet per minute, swelling as the air pressure decreases. It will burst when it reaches approximately 10 feet in diameter, usually around 70,000 ft altitude. The tattered remains of the balloon, and the payload, then descend on a parachute to the ground, usually dozens of miles from the point of launch. These are commonly executed and recovered by amateur radio operators and others using simple GPS location transmitters.

What is Long Duration Balloon Flight?

Balloon flights are considered "long duration" when they do not follow the traditional rise-until-you-pop flight path, but instead they level off, and float at a particular altitude. Large NASA "LDB" flight may float anywhere from 1 week to 90 days at their float altitude. However, those balloons require a special condition found only at the polar regions of the planet to accomplish this ultra-long duration flight - continuous sunlight. NASA balloons that have done this are large- extremely large - usually the size of an entire football stadium when inflated. Mere amateurs cannot hope to construct balloons of this scale. However, what has been discovered recently by amateurs, is that LDB flight is possible with small zero-pressure balloons. Perhaps even weeks if one could get to the polar region with an amateur balloon, but with significant work and planning, even at our Kentucky latitude, several days flight should be possible.

The Jet Stream is the way

The Jet Stream is a river of high speed air, that is about 100 miles wide, and about 10,000 ft thick, between 30,000 and 40,000 ft altitude. It travels usually at speeds of 100MPH to 200MPH. If you put a balloon into this raging river, and you hold your altitude, it will move as fast as the stream - up to 200MPH. You could make it from here to Europe in just 24 hours.

Cost

In the prior Spirit of Knoxville group, we paid about $200 for each trans-atlantic zero pressure balloon. The home-made electronics came to about $60 including GPS. Helium is about $100. The rest of the materials were trivial, probably $40 of payload box and parts to drop ballast. So the SNOX flights cost about $400 per flight. There were 5 full SNOX flights, the fourth is the one that made it across most of the way. Three of the five suffered significant failures: two of the balloon envelope, and one of the electronics.