HISTORY OF SOLAR BALLOONING
Throughout history, humanity has rehearsed with lighter-than-air vehicles aiming for a different way to move through and with the air, only with the power of the sun.
Presented here are various attempts of human Earthly circumnavigation, undertaken by people whose types of relationship to the atmosphere and the planet have become marginalised, and increasingly rendered invisible under the hegemony of the fossil fuel regime. In presenting these sustainable methods of movement, we aim to inspire the co-formulation of a renewed relationship to the Sun, re-attuning our somatic modes of attention to the atmosphere and the elements that envelop all life-forms. In doing so, new motional methods could become tangible, and an era free of carbon emissions and geopolitical dependencies realisable – moving us out of the Anthropocene, towards fossil free futures in Aerocene.
As fellow aeronauts, we hope this alternative history of energy pioneers creates a passageway that informs and empowers our ongoing aerosolar endeavours towards these unfolding possible futures. Further, this is a call to action: share your expertise and insights with the community – let us work together on the crucial points for further sustainable development of Aerosolar Mobility, already we have collectively performed the first certified fully-solar manned flight in human history – Aerocene is on the (up)rise, aeronauts unite!
1. SAFETY FIRST
It is essential that all aerosolar vehicles and flight attempts establish and follow safety measures. Secure locations and environments are, and always will be, the launch pad for all Aerocene activities, along with the support of on site, certified professional aerosolar pilots.
2. FULLY SOLAR
All flights described below have used propane for inflation, either during the flight or for landing. The exceptionality of Aerocene flights is the full exemption from the use of any fossil fuels or rare gases: from the very beginning to the very end, Aerocene journeys the aerial powered only by the Sun.
3. LEGAL FRAMEWORK
We encourage and constantly work with the Fédération Aéronautique Internationale (FAI ) to define a category for Solar Flights. In our endeavours to dislodge the hegemony of fossil-fuelled movement, and the socio-economic models which propagate them, working together for the recognition of Aerosolar technology is crucial to establish recognition of its viability as a possible new mobility form, as well as its social, political and ecological benefits.
Aerocene is currently in conversation with the FAA for the creation of an ad hoc new category, specifically for Fully Solar Flights with Lighter than Air vehicles. This would move our presence from Notable Flights (important achievements with no specific section) to a legitimate category that acknowledges the lack of propane used during Aerocene flights – truly zero-emission.
Upon achieving legitimised categorisation, Aerocene’s reclamation of the airspace from corporate interests and geopolitical control could enact the paradigm shift needed for an epoch liberated from the infrastructures of the fossil fuel regime, and its polluting practices, towards an era of decarbonization and the preservation of Earth’s life-transmitting aether—the atmosphere we share, the air we all breathe.
TETHERED TO AN ECOLOGICAL FRAMEWORK OF SUSTAINABILITY AND AWARENESS, TOWARDS A RE-ATTUNEMENT TO THE RHYTHMS OF THE PLANET AND ITS SPECIES, WE ASK YOU:
1. HELP US TO COMPLETE THE HISTORY OF SOLAR BALLOONING
2 DIT: do it together - SHARE YOUR FLIGHT DETAILS
Solar Ballooning . . . Before Aerocene
1794 - THE FIRST UNINTENTIONAL FLIGHT OF A SOLAR BALLOON
On 29th May 1784, an aerostat referring to Académie de Dijon in France, was lying on the ground, spreading out its 3565 m3 bladder. Still inflated from a previous flight, it’s recent polish treatment was able to dry without interruption. The aerostat stayed ground-bounded until the following day, when the sun came rising once more. It was strong this time, and temperatures higher than average. It was the beginning of summer, around noon, the breeze intensified and wind started blowing, circulating the balloon and soon shaking it to life.
Two guards assigned to keep an eye on the balloon tried to hold it down. They grabbed the affixed net but couldn’t resist its strength. The net broke and the aerostat started floating upwards. First, it flew into a courtyard, carrying with it the attached net and ropes adding up to 122 kg to its total weight. After making its way out the court, it flew east, then over a building close to another courtyard. A sixteen year old boy named Crosnier happened to see the flying structure, and attempted to help out. Weighing only 34,7 kg, Crosnier courageously grabbed onto one of the ropes, wrapping it around his wrist, hoping he could secure the balloon and bring it safely back to ground. In that very same moment, the balloon – instead of adhering to the human force trying to ground it – lifted up Crosnier, carrying him over a 2,9 m high wall before dropping him on the other side.
After this, the balloon traveled further, passing over Course de la porte Bourbon, where it was greeted by an astonished group of people running towards it, excited to see the spectacle. After a while, the buoyancy force decreased, and the balloon started to descend, eventually landing in recently planted trees, which teared the balloon apart across all its length.
“Voyages aériens” – by J. Glaisher, C. Flamarion, W.De Fonvielle et G.Tissandier – Hachette – 1870”
1970s – DOMINIC MICHAELIS AND HIS SOLAR BALLOONS.
Having completed his technical-speculative thesis on solar homes and floating solar villages, Dominic Michaelis graduated with a degree in architecture and engineering from Cambridge University in 1964. Bridging knowledge and know-how, Michaelis started working soon after his studies, managing an international consulting group called Solar Energy Developments. Together with his team, Michaelis realized a 45 m diameter Solar Dome for the movie Hu-Man, directed by Jérôme Lapérousaz.
Dominic Michaelis believed: an hot air balloon should be able to fly only with the power of the sun. To prove this hypothesis, Michaelis built a small balloon with a double skin envelope. The differential of temperatures from the inside and outside of the balloon was about 27°C, corresponding to a lift of approximately 100 grams per m3.
Michaelis started building more to prove his point. He tried with a larger balloon. It had a diameter of 10 m and was able to carry a lift as heavy as his son, Stéphane, weighing 30 kg. In turn, Stéphane became the first human pilot ever to be lifted by a solar tethered balloon.
In 1972, after Michaelis’ first balloon experiment had ended with the balloon escaping and flying away, Michaelis built a venturesome balloon: measuring a 22 meter diameter- around 5000 cubic meter – with a 12 micron transparent polyester film (Melinex® – Mylar® of DuPont Polyester Films), the balloon was monumental. Within its interior, three vertical black screens, with 120° between them, formed a trefoil. The air inside the balloon was heated through the greenhouse effect and the black screens absorbed the energy through the transparent polyester film. The envelope was reinforced by vertical and horizontal adhesive tapes (J-Lar910® or J-Larii®), which in turn defined 240 panels and limited possible tearing to a maximum length of 50 cm. The balloon was fitted with a very stiff but light structure: an aluminum honeycomb basket. This specific balloon could easily lift one adult man, which Michaelis went on to prove, undertaking various test flights in which he countered strong thermodynamic forces through tethering the balloon to a car, enabling it to rise skywards.
MICHAELIS AND THE FIRST MANNED SOLAR FREE FLIGHT IN EUROPE.
Following his successes, Michaelis’ focus became the performance of a solar balloon free flight. For this endeavour, Michaelis chose to build a balloon with a double envelope; the internal layer black, while the outer was transparent.
Commissioned by Michaelis to Cameron Balloons in Bristol, UK they produced a black balloon of polyester (Dacron®) with 3000 m3 and a double layered transparent (Melinex®) balloon with 4000 m3. The transparent outer skin consisted of two transparent films with an in-between layer of glue coated mesh reinforcement. Each hole in the mesh defined an air bubble which increased insulation.
The balloon’s transparent surface allowed air to flow in, enabling a greenhouse effect to take place. The inner black envelope absorbed the trapped solar radiation, transferring the energy to the air enclosed within it. The black balloon and the transparent envelope were working in tandem with each other in order to maximize the thermal insulation of the vessel.
The twin envelopes were attached to a basket carrying a gas burner, a construction to ease inflation, or to aid in the case of cloudy skies, covering the sunny day above. The altitude control was achieved through opening or closing horizontal panels located at the balloon equator. The deflation was made possible by rip-stop panels at the balloon crowns.
The balloon (number G-BAVU) participated in a number of hot air balloon festivals in England from 1976 to 1980. The flights were usually performed during the late evening in such a way that, should a valve fail, the uncontrollable balloon would not rise too high.
Crucial to the balloon chronicles of the 70’s was also Tracy Barnes. The US pioneer made several solar flights under tetrahedral single-skin solar balloons, one of which he named ‘Barnes Solar Firefly Tetrahedron’. Barnes first piloted a fully-solar-powered balloon flight on 1st May 1973, followed by Jim Woodman with the Condor I and Fredrick Eshoo with the Sunstat soon after.
MIR (MONTGOLFIÈRE INFRAROUGE) : THE STRATOSPHERIC BALLOON OF CNES
Since 1977, the Centre National d’Études Spatiales (CNES, the French equivalent to NASA) has been developing the MIR balloon for long durational scientific stratospheric flights.
During the day, the MIR balloon flies at an altitude of about 28 to 32 km. During the night, between 18-22 km, depending on the infrared flux radiating from the surface and the temperature of the air at flight altitude. The MIR is a hot air balloon “open at the bottom”, using a helium complement for takeoff. It can carry a maximum payload of about 50 kg. The balloon route follows stratospheric winds and indeed, they are able to circumference all around planet Earth.
Designed with a reflective surface, the balloons are buoyed only by the heat from the sun during the day and the infrared radiation from the earth during the night. The “passive” heater warms the air inside the balloon, lifting up the vehicles, which range in sizes from 35 000 m3 to 45 000 m3.
The MIR is made from two different materials, offering a good balance between optic-thermal properties and weight. The top part is made of aluminized Mylar, 12 μm thick, forming a cavity for absorbing ascendant infrared radiation and blocking any re-emissions into the sky. Meanwhile, the bottom part is made of 15μm thick linear polyethylene. It is an infrared transparent material tough enough to withstand the extreme cold temperatures of the stratosphere, measured at an average of -80°C.
1980s – JULIAN NOTT AND THE CHANNEL CROSSING
The 9th Congress of the International Solar Energy Society (ISES) was held in Brighton, UK, in 1981. Balloonist Julian Nott had achieved a world record the year before, having reached an altitude of 55,000 feet. Aiming higher the following year, Nott wanted to not only rise up but to travel far. He decided to use Dominic Michaelis’s solar balloon in an attempt to cross the English channel’s aerial scope.
Nott’s ascent skywards began at 7:30 am on 22nd August 1981, North West of Dover, UK. After a very silent channel-crossing without any troubles, the balloon landed at Tournehem sur la Hem in the Pas-de-Calais, FR. Nott only used the burner once, during the landing. The envelope of this solar balloon is conserved at the British Balloon Museum, a testament to its groundbreaking status in balloon travel history.
1990s – ENCLOSING A CLOUD IN A BALLOON: JEAN-PAUL DOMEN AND THE BULLE D’ORAGE.
A revolutionary hot air balloon
Jean-Paul Domen, an independent engineer, recalls his solar balloon experience “…at the beginning, I wanted to make a solar balloon. I didn’t know it was already made and even distributed by the kid magazine Pif Gadget : some plastic trash bags to build a black screen, adhesive tape to put together the envelope. Build it in my kitchen … Launch… and a ridiculous result : my toy got into a tangle at the top of the TV antenna of my neighbor… anyway, it flew for a short while. From this time, I have extrapolated to build a solar balloon able to lift a human to a high altitude. Computing all that I noticed that the needed energy increase faster with the balloon size than the energy actually intercepted. To sum-up the bigger the balloon the slower it rise. So we need an energy proportional to the volume.”
A huge amount of energy accumulates in thunderstorms. It is caused by a rapid rise and falling currents of air. Jean-Paul Domen found a solution to this power conundrum: within a cumulonimbus cloud, the vertical velocity can reach 100m/s because of the heat generated by the condensing water vapor. But “what if we’d do the same inside the balloon, enclosing a small cloud?” Domen thought. Thus, the Thunder Cell Balloon was born.
From this point on, Domen started storing water vapors inside his balloon envelopes. During the ascent, the sun heats up the air enclosed within the body. When the “point de rosée” (dew point altitude) is reached, it is mainly the condensing water vapor that provides the energy needed to continue the ascent. The best conditions to experiment with these type of balloons would be on a sunny summer day, floating at around 2000m altitude.
Domen went on to make a vapor generator adapted from his earlier balloon experiments, testing these during flights to see how they performed. From 1992 to 1996, successful test flights excelled, becoming the Bulle d’Orage. It’s aim was to lift a heavy payload into the stratosphere:
15 May 1992. Payload 1 kg – Balloon 30m3 – Altitude reached : 18000m.
6 May 1993, Payload 40 kg – Balloon 600m3 – Altitude reached: 12200m.
February 1996, Payload 270 kg – Balloon 8000m3 – 25m diameter – Altitude reached: 12000m.
In the summer of 1996, Jean-Paul Domen performed the first free flight of a solar balloon which covered a distance of 300m. The balloon was 16m in diameter while inflated with ambient air (i.e. without adding vapor). The balloon consisted of a simple envelope made from black polyethylene. It’s thickness was 15 microns with a valve of 2,5m diameter attached to the top. The bottom opening was about 2m wide. Here sat a propeller driven by an electric motor which allowed for a controlled inflation/deflation of the balloon, through which altitude could be adjusted.
Gérard Auvray Collaboration
Together with Gérard Auvray, the electronic engineer and radio ham F6FAO, Jean-Paul Domen utilised 4m diameter solar balloons for experiments into transmitting temperatures, humidity, and other meteorological data.
The 6 July 1997 takeoff from Arachon at 09:30, saw a 4m balloon with a 500 gr payload rise into the sky. Onboard: a power card, an analog to binary converter card, an analog/digital/format packet, and card probe anda bip-bip transmitter. The balloon ascended to more than 18,000 m. The outside temperature registered -50°C and the polyethylene temperature hit 80°C! The balloon landed close to Marseille at around 23:30.
The localization of the balloon during the flight was made possible by radio ham (chasse aux renards).
The collaborative endeavours of Domen and Auvray currently focus on a solar drone with a 6m wingspan, weighing 7kg. This drone will be assisted through the dense layers of the atmosphere by a solar balloon, which will carry it to high altitude then detach. In its total autonomy, the drone will then cross the Atlantic. It will use the stratospheric winds that flow from east to west, opposing the atmospheric currents; there will be no clouds at this height and the day zone also traces to the west. It will compute it’s route with the help of a microprocessor linked to a GPS and an inclinometer. and to the engines from Emmanuel Laurent and François Kormann.
ALEJANDRO URIBE AND THE LARGEST SOLAR BALLOON
In 1998, in Medellin (Colombia), Alejandro Uribe aimed to change the tradition of paper balloons, which use only the sun to heat their upward journey. In South America, particularly in Brazil, there is a tradition of flying hot air balloons. Local communities put them together, using silk or kraft paper. Sometimes reaching more than 60 m tall, these balloons are a part of various regional cultures, and are present during many societal celebrations. Here, tethered balloons of all sizes and shapes fly around. Surrounded by human shouts and other symbolic gestures, the balloons carry banners and various candles, illuminating their journeys as they travel through the night.
A gas burner is placed under the balloon envelope, heating up the air. During the day, children and adults follow them, eagerly trying to be the first to catch one as it succumbs to gravity’s embrace, becoming Earthbound once more. What some often forget, however, is that these balloons can start grave fires. Forest fires, household fires, and other damaging consequences happen more frequently then one might think.
In December 1995, near Medellín, a paper balloon instigated a fire that completely destroyed the Renault industrial plant, la SOFASA. Following this event, the police took action, destroying all balloons in the country, including those under construction. They also forbid all future balloon flights, the risk was too high to allow them to become airborne.
In Brazil, the gas burning balloon tradition has been forbidden since 1998. Yet, the baloeiros (‘the balloon makers’) remain committed to their traditions, continuing to build giant paper balloons and launching them over neighborhoods, undercover.
Living locally is Alejandro Uribe. While remembering a gimmick illustrated on the milk pack labels in the 80s, Uribe was inspired. The gimmick depicted a cylindrical solar balloon, the same as the Pif Gadget recalled by Jean-Paul Domen. From Uribe’s milk pack memories, an idea started to take shape. He wanted to evolve the repressed balloon tradition.
Drawing from the paper balloons powered by gas, he started reconstructing them, designing them to use the simplicity of solar energy. He then employed polyethylene, which is much more efficient in absorbing solar energy than silk paper. In 1998, Ubrie made a 5m solar balloon assembled from black trash bags. One of them, which hosted a reflective panel, was once mistaken for an UFO and caused great fear in the population. Initially, Uribe manufactured solar balloons with black polyethylene but soon went on to experiment with colored polyethylene, as well as non-symmetrical shapes.
To welcome the beginning of the 21st century, Uribe inflated a structure 135m long, composed from 250 kg of polyethylene and 17 km of tape on the 31st December 1999. A lot of people turned up to participate in lifting of the largest solar balloon ever built. The event was covered by an extensive press and media presence. A musician played the flute directed to the inside of the balloon to improve its chances and its luck.
The balloon started dancing with the winds, losing its shape a few times along the way, before finally ascending into the sky above the town. Unfortunately, the endeavour was ill-fated. After only 15 minutes of buoyancy, a huge hole caused the balloon to crash into some power lines. Luckily, a diligent team were quick to recover the balloon, repairing it within 20 days. It was then ready to attempt it’s first flight of the century on January 23th 2000. This time, it was successful.
Following this triumph, Uribe continued to test and experiment with many different balloon shapes and sizes. To support the living tradition of the balloon festival, Uribe organizes the Fiesta del Globo Solar – Festival of Solar Balloon every year throughout the month of December, active since 2001.
2000s – LAURENT BESSET CARRIES OUT DOMEN AND AUVRAY’S LEGACY
In Spring 2000, Laurent Besset discovered the solar balloon after a meeting with Jean-Paul Domen and Gérard Auvray, ultimately deciding to continue the legacy of their project.
Prior to this decision, Laurent Besset had built an electronic card performing two functions:
1. An auto stabilizer of the flight altitude: a software that controls the opening and closing of a valve at the top of the balloon, a servo control wind up or unwind the string controlling the valve.
2. A display parameters for manual control of: altitude, inner temperature-outside temperature, distance envelope to valve, battery power level.
In the summer of 2000, Besset undertook calculations and tests on the following items: envelopes (template, build method, sizing of the valve, the rip panel, rotation panel), loading circle link to the polyethylene envelope, harness ballasts (fastening on the loading circle), materials for inflating (protection fabric on the ground, fan, tethering) and building the altitude control. During the summer of 2001, Besset performed some tethered test flights with an 11m and 14,5m balloon, undertaking many indoor tests of their electronics, such as altitude autopilot mode, simulating altitude variation, distance envelope to valve variation and software modifications. Besset ultimately created a mini-balloon which could be built in a living room by anybody using certain guidelines and instructions.
Other important figures in the developement of these tests are Emmanuel Laurent et François Kormann, membres du GRETSS (Groupe de Recherche et d’Etudes des Techniques Spatiales de Strasbourg).
2010s – CHRISTOPHE PRATURLON AND THE SOLAR JUMP
In January 2011, at the 9th Dolomiti Balloon Festival in Toblach / Dobbiaco in South Tyrol, the Solar Jump, performed by Christophe Praturlon, took place.
FIRST WEATHER DETECTION WITH SOLAR BALLOON
The first 100% solar weather probe, named Ballon ORA, was launched from the French Antarctic Dumont d’Urville Station in January 2011 by a joint team of students, scientists and engineers.
The aim was to assess the feasibility of using solar balloons as probes in remote areas, where saving the use of lifting gas, helium or hydrogen, would be even more advantageous. The flight was a success, reaching 46,000 ft (14,000 m). The benefits of this success do not only concern the elimination of lifting gas in itself, the ORA Balloon further alleviates the need for resource transportation and of the heavy gas canisters they are transported in.
Thanks to every aerosolar dreamer sharing their adventures around the Planet- if you have any stories or inquiries please contact us and contribute to the preservation of solar energy history, and recognition of its pioneers.
We look forward to further learning together,