Auguste Piccard piloted a balloon through an extended ascent into the stratosphere, presaging the space age with his pioneering use of a controlled-environment cabin.
In the early 1930’s, the last of Earth’s physical frontiers were slowly being understood and conquered. Stories of humankind pushing its limits regularly qualified for the front pages of major newspapers. When Auguste Piccard and Paul Kipfer ascended to 15,781 meters (approximately 51,775 feet) to break the world altitude record in a balloon of Piccard’s own design, the world was enthralled and the scientific community gained new venues for exploration.
The stratosphere remained as one physical barrier that had been touched previously only barely. In 1902, Léon Teisserenc de Bort discovered the stratosphere, a layer in the atmosphere above the troposphere. There, the temperature does not decrease with altitude but is approximately constant at –55 degrees Celsius. The altitude of the lower boundary of the stratosphere varies greatly; a useful average is 12 kilometers (about 7.46 miles). Because barometric pressure decreases with altitude, the ambient pressure at such an altitude is about one-sixth that at Earth’s surface; at 16 kilometers (9.94 miles), the fraction is only about one-tenth.
Prior to 1931, only two humans0 had been able to penetrate beyond 12 kilometers, and neither had available to them technology that would sustain life at that altitude for extended periods of time. In 1927, U.S. Army captain Hawthorne Gray
In the two decades preceding Piccard’s flight in 1931, the realm of high-energy physics saw unexpected developments. Victor Franz Hess
The balloon Piccard designed incorporated several innovative features. Most notably, the gondola was to be sealed and airtight, so that air pressure inside the gondola would not be lost as the balloon ascended to regions of lower and lower pressure. Piccard chose to construct the gondola out of aluminum, a material that had been under development only recently. Because the flight would be many hours long and the gondola relatively small, there needed to be a source of oxygen as well as a way of detoxifying exhaled air. For these purposes, Piccard imported technology used in German submarines, a filtering system known as a Draeger apparatus. It utilized alkaline compounds to absorb unwanted gases. The oxygen supply was stored in liquid form; it restored the cabin air as it slowly vaporized.
The balloon envelope was spherical, as was usual for hydrogen-filled balloons. The constraints of a high-altitude flight, however, dictated some adjustment. To prevent the lightweight rubberized cotton balloon from bursting as it ascended into the low pressures of the stratosphere, the balloon was only partially inflated at takeoff. The balloon, which was pleated for storage, would unfold and expand of its own accord as it ascended. To ensure that the fabric unfolded safely, Piccard devised a way to hang the gondola to the envelope from points on a horizontal band attached to the envelope, rather than from a net that enclosed the envelope.
Piccard applied for funding from the Belgian science agency, the Fonds National de Recherches Scientifique (FNRS), founded by King Albert I. As the king was eager to promote Belgium’s reputation as a leading nation in scientific and industrial endeavors, and given that he was a balloon enthusiast himself, he was happy to provide the necessary funds. The craft, named the FNRS, was ready in the fall of 1930. Piccard scheduled an ascent for September 14, from Augsburg, Germany. The weather changed, however, and Piccard reluctantly called off the flight at the last moment. Weather conditions were not suitable again until the next spring. An ascent was finally planned for 5:30
As the day progressed, Piccard and Kipfer discovered a problem with the gas exhaust valve. This was the valve with which they were to let gas out of the balloon, a principal component of their altitude control. Their eventual landing would be problematic if they could not control the valve. The only way to proceed was to wait until sundown, when the lower temperature would cause the balloon envelope to shrink, thereby reducing the lift sufficiently for a landing. Piccard and Kipfer tied down the instruments in anticipation of a difficult landing. Hours passed, and the balloon drifted southward over Bavaria and into Tyrol. Finally, around 9:00
Piccard had planned several scientific activities for the ascent of the FNRS. The quick rate of ascent, the emergency leak that had to be taken care of, and the uncertain landing all conspired to prevent any measurements from being made while the balloon was at any other but top altitude. Piccard and Kipfer thus lost their opportunity to obtain many useful data, such as information on cosmic-ray altitude-intensity curves. One approximate observation was made, however, that suggested cosmic rays were indeed more intense in the stratosphere than below it; this, in turn, lent support to the theory that cosmic rays are in fact extraterrestrial.
For their achievements, Piccard and Kipfer were knighted by the King of Belgium, and Piccard received nominations for the Nobel Prize in Physics in both 1932 and 1933. Their altitude record of 15,781 meters stood for more than a year, until it was surpassed by Piccard and Max Cosyns.
The flight of the FNRS made its mark on a wide cross section of the scientific world, less by resolving scientific controversies than by preparing the way for further exploration. The data obtained on the flight were encouraging. Piccard and Kipfer measured cosmic radiation apparently 2.5 times more intense at 16 kilometers (9.94 miles) than that measured by Werner Kolhörster at 9 kilometers (5.59 miles). This piece of information was only marginally useful, however; because only one measurement was taken, it could not be calibrated with data from previous flights at lower altitudes, and its accuracy was not absolutely certain.
Nevertheless, this first flight gave subsequent balloonists a resource of experience and technology from which to draw. In fact, the next stratospheric ascent, with Piccard and Cosyns piloting the FNRS in August, 1932, was quite successful scientifically as well as logistically, bringing back data to fill in the Hess-Kolhörster cosmic-ray altitude-intensity curve between 9 and 16 kilometers. A 1934 flight in Explorer II by Americans Albert Stevens and Orvil Anderson returned cosmic-ray data that physicists Robert Andrews Millikan and his rival Arthur Holly Compton both considered useful for their respective theories. In addition, the flight carried interesting experiments in other branches of science. For example, Stevens and Anderson measured ozone distribution in the atmosphere, photographed Earth from very high altitudes, and demonstrated an increased mutation rate in fruit flies. Piccard’s vision of the balloon as a platform from which to conduct scientific research thus did prove moderately productive.
Ascents subsequent to those of the FNRS retained many of Piccard’s innovations. For example, American balloons such as Explorer used bands also rather than nets to attach the gondola. Most significant, however, was the sealed gondola. As late as 1956, balloons such as Stratolab were still using a gondola of essentially the same design as that of 1931.
The flights of the FNRS preceded the space age by only three decades. During those years, stratospheric ballooning evolved from a matter of rising in open-air baskets to one of orbiting Earth in space capsules. Pressurized passenger airplane cabins and the modern-day space shuttle trace their ancestry to the sealed cabin that Piccard devised for his FNRS. Although the impact of Piccard and Kipfer’s ascent into the stratosphere reaches beyond the glory that their achievement brought, the glory itself was instrumental in promoting ballooning to the public and to policy makers. Proponents of aeronautic exploration in the United States in the following decades pointed to the flights of the FNRS to convince major funding agencies that research in high-altitude flight was feasible and that the symbolic value of accomplishing such flights was worth the expense. Both technologically and sociologically, it was only a small step between the Stratolab 5 balloon flight in 1961 and the Mercury, Gemini, and Apollo space missions of the same period. To those who came after Piccard, his flights stood as vital inspiration and encouragement.
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DeVorkin, David H. Race to the Stratosphere: Manned Scientific Ballooning in America. New York: Springer-Verlag, 1989. Excellent history of ballooning and analysis of science policy by the curator of the Smithsonian Institution’s National Air and Space Museum. Focuses on ballooning in the United States, but Piccard and his twin brother, Jean-Felix, figure prominently in the story. Well-researched and highly readable resource. Includes reference notes and extensive bibliography. -
Piccard, Auguste. “Ballooning in the Stratosphere.” National Geographic 63 (March, 1933): 353-384. Consistent with its calling to promote exploration, the National Geographic Society supported scientific ballooning from the start, publishing reports of projects such as Piccard’s in its popular magazine. -
_______. Earth, Sky, and Sea. Translated by Christina Stead. New York: Oxford University Press, 1956. First-person account of Piccard’s voyages into the stratosphere and later, in a bathyscaphe, into the depths of the sea. Provides a personal perspective on his work. -
Sekido, Yataro, and Harry Elliot, eds. Early History of Cosmic Ray Studies: Personal Reminiscences with Old Photographs. Boston: D. Reidel, 1985. Anthology of writings by leading cosmic-ray researchers provides a depiction of the birth of the field that is balanced and thorough. Acknowledges and describes the roles of manned and unmanned balloons, underwater observations, and developments in theory. Often technical, but aimed at the general science reader. Includes photographs, illustrations, notes, and index. -
Stehling, Kurt R., and William Beller. Skyhooks. Garden City, N.Y.: Doubleday, 1962. Details the stories of fifteen historic balloon flights from the birth of ballooning in 1783 to the early 1960’s in a manner accessible to the general reader. Chapter on the flight of the FNRS contains some minor inaccuracies. Includes a chronology of important ascents.
Hess Discovers Cosmic Rays
Millikan Investigates Cosmic Rays
Lemaître Proposes the Big Bang Theory
Discovery of the Cherenkov Effect