The balloon connection 25 March 2020

By Ian Parker, freelancer,

Sometimes the oldest ideas combine with the newest to produce wonderful results, which is the case regarding the Loon LLC project – a combination of balloons and internet electronics to give online coverage in remote parts of the world at a significantly lower cost compared with satellites.

Ballooning is nearly 2,000 years old. Around 250 AD, the Chinese used them for military signalling. The first flight carrying people was by the Montgolfier brothers in France in 1783. In 2012, Felix Baumgartner jumped from a balloon in the stratosphere and reached 850mph, before ‘slowing down a lot’ for a safe landing. Hot air ballooning is a thriving sport around the world. On many a calm summer’s evening, they can be seen flying regally across the sky.

Balloon people are unusual and so are their craft’s uses. During the Siege of Paris (1870 – 71), Leon Gambetta, the minister for war, was flown out by hot air balloon. Quite a few people escaped by this method and over 60 unmanned messenger balloons were sent out, most of which were found, and their messages delivered to the intended recipients.

The Prussian gunners surrounding the city were highly frustrated by this activity because they were not prepared for balloons being used for such purposes. Consequently, their guns could not be elevated enough to fire at the balloons. The escaping Parisians, delighted at their untouchable elevation, expressed their contempt for the gunners as they flew overhead and poured scorn on them as well as various ‘unpleasant substances’.

Over the centuries, balloon journeys got longer until in March 1999, Bertrand Piccard and Brian Jones successfully flew a balloon around the world. Being surprised at the unexpected uses of balloons has continued since their invention and their speed and altitude capabilities continue to increase.

Old supports new
Now, balloons are being combined with internet electronics to give internet coverage in remote parts of the world. Some 4.5 billion people around the world do not have an internet connection. The potential for a connection to improve the lives of very poor and very remote people is huge. It can be done by satellites; but the cost of such a system is high and, like anything else, it must be economically viable before it can be established.

The company planning this is called Loon (a reference to ‘lunatic’ or ‘loony’ and ‘balloon’). Since many industry observers initially thought the idea was lunacy, the planners decided to coin a name which is attractive, entertaining and with the potential to say: ‘So you thought we were loonies’ if it becomes successful. There is no question that the idea is loony. The question is whether it is loony enough to be a huge success – recent indications are that it is.

Loon (a subsidiary of Alphabet Inc) has taken the most essential components of a cell tower and redesigned them to be light and durable enough to be carried by a balloon about 20km up, on the edge of space. Loon balloons are designed and manufactured to endure the harsh conditions in the stratosphere, where winds can blow at over 100km/hr, and temperatures can drop as low as -90°C.

Stratospheric winds blow in various and somewhat predictable directions so the balloons can be navigated remarkably accurately – it is not a case of them drifting around unpredictably as most people would assume. By varying the altitude of the balloons, they can be steered. This technique of navigating balloons has been used for decades by the leisure balloon community and facilitates balloon races, even with tacking ‘up wind’ like a yacht.

A less obvious challenge is the construction of the balloons to stand the severe environments in which they operate. Much of this challenge concerns how the balloons are constructed and held together. Made from sheets of polyethylene, each tennis court sized balloon is built to last for well over 100 days before being brought down.

The balloons make a controlled descent gently by parachute at the end of life. Nobody wants a few hundred pounds of electronics and solar panels crashing down on them. Each balloon/payload has a notice on it about what it is and who should be alerted, in case it’s not retrieved immediately by Loon – in effect a ‘may we have our balloon back please’ type message.

Materials and manufacture
The balloon envelopes are designed and made by Raven Aerostar and are based on its Super Pressure Balloon product (internal pressure somewhat above ambient). Most balloons (particularly leisure hot air types) are not super pressure, so don’t need to be as strong.

The balloons are composed mostly of polyethylene, about 0.076mm (0.003 inch) thick. They are some 15m (49 feet) across and 12m (39 feet) tall when fully inflated. Firstly, ‘gores’ (sections) are made, which are bonded together with a proprietary method and materials.

This is a highly critical process because the balloons' leak rates must be very low and the seams must not fail. Raven is understandably coy about its precise manufacturing procedures and materials.

Preventing those leaks, in the gores and in the seams, is the work of a squad inside Project Loon that has doggedly chased down every possible cause and come up with preventive measures. These researchers have studied balloons retrieved from the stratosphere, poured over video footage of others inflated to bursting point on the ground, and developed a ‘leak sniffer’ to find tiny holes by detecting helium. The leak squad’s findings have led to changes in the design of the balloon envelope; fluffier socks for workers who must step on the envelopes during production; and new machines to automate some manufacturing steps.

“Altogether, Google X (which started the project) has introduced the first major changes the balloon industry has seen in decades,” says Mahesh Krishnaswamy, who oversees manufacturing for Project Loon and has previously worked on Apple’s manufacturing operations. “Those changes have paid off. In the summer of 2013, Loon balloons lasted only eight days before having to be brought down. Today balloons last on average over 100 days, with most exceeding that time in flight; a handful have lasted as long as 130 days.”

Google X enlisted experts in ballooning, aerospace, textiles and other disciplines to learn why they were failing. It hired ex-military personnel to retrieve downed balloons, which sometimes fell in hard to reach places.

“Raven Aerostar is our balloon design partner and manufacturer of our envelopes. It brings to the project decades of expertise in high altitude balloon engineering, as well as the latest breakthroughs in super pressure balloon engineering,” comments Mike Cassidy, former project lead at Google X.

Some of the testing has been carried out in extreme conditions such as those the balloons might face in the atmosphere. At one point, temperatures fortuitously dropped to sub-freezing temperatures in South Dakota, one of the balloon manufacturing locations. More recent testing was done at the McKinley Climatic Laboratory at Eglin Air Force Base in Florida, which allowed the team to subject the balloons to extreme weather conditions, such as high winds and below freezing temperatures, in a controlled lab environment. Many of the failures were found to be caused by tiny leaks that were hard to detect. Even the tiniest pin sized hole greatly decreases a balloon’s time in the air. Leaks through the fabric must me minimal too. Hydrogen and helium are tiny atoms, which will escape through many materials. Due to the findings, the seams were strengthened, and more careful balloon handling protocols were implemented.

Aside from improving the viability of its own project, Google’s efforts have provided breakthroughs in ballooning generally. Due to design improvements, balloons now stay afloat for around 100 days. One even stayed up a record 187 days and circled the planet nine times. These are flight times that were unheard of before, and previously considered by some experts to be impossible.

The contribution of the fasteners and fixings industry is a vital part of this project. The balloons must last in very harsh conditions and therefore their construction must be of the very highest standards. The biggest challenge is the seams that join the balloon gores together. Their integrity must be second-to-none. Loon uses a proprietary tape and adhesive system, which has performed extremely well so far in all balloon tests and operations.

“Our work with Loon aligns with our purpose to connect, protect and save lives, and the accomplishments and milestones achieved are a testament to our team’s commitment to innovation,” states Scott Wickersham, Raven’s quality and service division vice-president and general manager.

As part of Raven Industries, Raven Aerostar traces its roots back to the General Mills Applied Sciences division, where barrage balloons and other scientific items were developed and manufactured for the war effort. Raven’s founders had a passion for ballooning that compelled them to advance and develop all other aspects of ballooning. “Our ‘lighter than air’ platforms have helped NASA, Google, the US Air Force, and many other customers achieve and exceed dynamic missions, including communications, data relay, surveillance, intelligence, and more,” says Raven.

A passion for odd things can often result in people being somewhat ostracised. These things can then sometimes become hugely beneficial. In the early 1800s, Michael Faraday discovered the principles of electromagnetic induction at the Royal Institution in London. The prime minister saw his demonstrations and is reported to have asked “Of what possible use is this?” Faraday replied: “I do not know yet sir, but whatever it is, I’m sure you’ll find a way of taxing it.”

The principles which Faraday discovered are now connecting the world, in concert with balloons for remote areas. The joining of these two things will be great. Who would have thought that balloons and electronics would be merging to meet this fundamental human need? What things will merge next to meet great demand? That’s not certain, but what is certain is that they’ll all need fasteners and fixings.

Freelance Journalist

Ian Parker Freelance Journalist t: 07710 810957


Ian Parker graduated from Loughborough University with a BSc in ergonomics in 1979 and then joined the staff of Flight International as an editorial assistant. In 1985 he joined Shephard Press where he edited Space, Aerospace Materials, Helicopter World and Defence Helicopter magazines. In 1998 he joined US publisher Access Intelligence as European editor of Rotor & Wing, Avionics, and Aviation Maintenance. In 2001 he went freelance, writing on a wide range of engineering topics. In 1997 he won the excellence in communications award from the Helicopter Association International. For many years he was a class rating instructor on the Yakovlev 18T and 52 aircraft.