THE GONDOLA OF THE BALLOON in which Professor Piccard ascended into the stratosphere was hermetically sealed. This was an innovation in the history of ballooning. Past experience had shown that oxygen masks and pressure suits had their possibilities, but Piccard wished to be bodily transported, with his normal supply of air and in his normal surroundings, into a region where life would ordinarily be impossible. All stratosphere ascents by balloon since Piccard’s first attempt have been made in hermetically sealed gondolas.
THE first man to enter the stratosphere in a balloon and to return alive was Professor Auguste Piccard, Swiss Professor of Physics at the University of Brussels. On May 27, 1931, he and his assistant, Paul Kipfer, reached a height of 51,775 feet - nearly ten miles - and laid one of the foundations of stratospheric research.
Professor Piccard had been carrying out cosmic ray investigations for some time in his laboratory in Brussels, and, having realized that these rays came from outer space, he was attracted by the idea of studying them at closer quarters. He wished to study them at a point where they would have penetrated only one-tenth of the Earth’s atmosphere. Calculations led him to believe that this point would be reached at an altitude of about ten miles.
At the time, the official altitude record was held by an aeroplane which had attained a height of 43,166 feet, but Piccard decided to use a balloon. This would allow him to carry certain delicate instruments which would not have given reliable results inside an aeroplane.
The design of a suitable balloon, from the mathematical and scientific point of view, offered no insurmountable difficulties. It was largely a matter of obtaining the correct relation between the balloon’s capacity and the weight to be lifted. One feature came into play, however, which did not concern the designers of balloons for normal purposes. This was the fact that, because of the exceedingly low pressure which would be encountered, the gas within the balloon would expand, at great heights, to about ten times its normal volume at sea level. Thus, a balloon was required of great size which would rise from the ground when filled with hydrogen of only about one-fifth of its eventual volume. Then, in the upper atmosphere, the reduced pressure and the heating effect of the sun would cause the gas to expand, and would give the balloon extra lifting power which would carry it upwards for several miles. The balloon would be pear-shaped at the start and spherical at its upper limit, where an excess of gas could be allowed to escape through the normal valves and controls.
The real innovation introduced by Professor Piccard was the hermetically sealed gondola in which the ascent was made. Past experience had shown that oxygen masks and pressure suits had their possibilities, but Piccard wanted to remain in his normal surroundings and to be bodily transported, with his normal supply of air, into a region in which life would ordinarily be impossible.
The hermetically sealed gondola was an innovation in the history of ballooning, but all the stratosphere balloon flights made since Piccard’s first ascent have been made on the Piccard system.
The gondola built for the ascent was 7 feet in diameter. Lightness was an important consideration, and for this reason the gondola was built of an aluminium alloy a mere eighth of an inch in thickness. The method of maintaining a steady and adequate air supply was evolved from submarine practice, and was known as the Draeger system - a process of air conditioning which consisted of replacing the spent oxygen and extracting the carbon dioxide by a chemical process. The apparatus was light and compact, and it provided the crew of the gondola with an adequate quantity of fresh air during the entire flight.
The gondola was fitted with two man-holes and eight portholes; on circular panels round its walls were meteorological instruments and delicate apparatus for the study of cosmic rays. An interesting experiment was the painting of one side of the sphere with black paint, the other side being left white. Piccard hoped,by an arrangement of a little propeller at the end of a projecting arm, to be able to move the gondola round at will. A black surface absorbs heat, and a white surface reflects it. The purpose of the paint was to make it possible to control the heat inside the gondola by turning either side towards the sun.
Unfortunately, the propeller arrangement did not work, and the stratosphere explorers were forced to endure a temperature of 104 degrees Fahr., with a temperature of 60 degrees below zero on the outside of their thin aluminium shell.
A balloon of enormous size was necessary. Its capacity when fully inflated was 500,000 cubic feet - some ten times greater than that of the average balloon Used for work at normal heights. The balloon weighed about 1,500 lb and had a diameter of 99 feet. The difficulties of inflating it were considerable; for, although the weather was perfectly calm at ground level, tile enormous bag, pear-shaped when partly inflated, would reach high into the region where there were gusts of wind.
Failure of the Release Valve
It was also desirable that the ascent should be made from a place far distant from any great expanse of water, for balloonists have a natural dislike of being forced to alight on the sea. Eventually it was decided to inflate the balloon at Augsburg, Bavaria, at the aerodrome of the firm which had manufactured it.
Conditions appeared favourable for an ascent on September 13, 1930, and everything was prepared. Inflation was begun late in the evening, In the presence of a large crowd of spectators. At the last moment, however, clouds appeared, the barometer dropped rapidly, and a. light wind sprang up. An accident seemed inevitable, and the balloon was emptied. Professor Piccard had to wait eight months until conditions were favourable again.
Inflation was begun again at midnight on May 26, 1931, and early the next morning everything was ready for the ascent. The wind was springing up, and the aluminium gondola was being blown about on its journey across the aerodrome. It was badly dented, and some of the apparatus installed in it was put out of adjustment by the jarring which it had received. An early start was planned. Professor Piccard and his assistant climbed into the gondola and were sealed in at about 3.30 a.m. The balloon was released before they were completely ready, and rose almost vertically, quickly disappearing from the view of the thousands who had congregated to see the start.
Then came the first hitch. Piccard was busy with the insertion of an electrostatic sounding instrument in the one hole in the gondola which had been left open - a small aperture about one inch in diameter. He found, to his dismay, that the rim of the hole had been bent during the buffetings which the gondola had sustained, and that the instrument could not be made to fit. As the balloon was ascending quickly, air was escaping rapidly through this hole; unless this escape could be checked, there would be nothing to do but to check the ascent by releasing gas. As it happened, the release valve was not operating, because the valve rope had been twisted at, the take-off. Fortunately, however, the aeronauts knew nothing of that at the time. Had they known it, they would probably have descended immediately.
At 15,000 feet the recording instrument was at last forced into the hole, but the escape of air was not checked completely and a telltale whistling noise proclaimed that the internal pressure was still falling rapidly. By pouring liquid oxygen on the floor Piccard prevented for a time any further fall in internal pressure, and finally the leak was stopped with a mixture of oakum and petroleum jelly. After twenty-eight minutes Piccard and his assistant were at last able to take some observations, and it was found that they were at an altitude of some 50,000 feet. The sun was shining brilliantly from a sky of a beautiful deep purple and the moon also was a brilliant object in the sky. Occasional glimpses of the Earth were possible, but misty weather prevented detailed observations. More serious work, however, than the observation of the beauties of Nature was before the aeronauts, and they began their scientific observations at once.
Ballast of Lead Dust
The balloon was moving slowly, and it was levelled off at a height of 49,100 feet. Now the professor made the alarming discovery that the release valve would not work, but he knew that the balloon would descend of its own accord when the sun set and the temperature fell. This discovery made him extremely careful about the oxygen supply, as the flight was obviously to be prolonged beyond original expectations.
It was discovered, too, that the electric motor designed to operate the propeller for turning the gondola would not work, and as the black side was facing the sun the inside temperature rose steadily. The supply of drinking water was exhausted, and the two men, one-eighth of an inch from nearly 100 degrees of frost, were enduring the conditions of an earthly heat wave. Some of the rubber joints of the manholes were becoming warped by the heat and the internal pressure began to fall again. This necessitated the use of more and more of the precious supply of oxygen. These circumstances combined to limit the height of this first ascent. Piccard and his assistant had used little of their ballast - lead dust was used instead of sand - but, although they might have risen at least 2,000 feet higher by using more, they decided otherwise.
Early in the afternoon the balloon began to sink at the rate of about 100 feet an hour. As this meant that it would not reach the Earth for three weeks, Piccard and his assistant were not particularly happy; but as the evening lengthened the rate of falling increased. At last - by 8.50 p.m. - they were only some 12,000 feet above the ground, and decided to open the manholes. The balloon was now over some high mountains and, although it was not in any way under the control of the aeronauts, it made a safe landing in Austria on the Gross Gurgl Ferner glacier, nearly 9,000 feet above sea level.
INSTRUMENTS AND EQUIPMENT used by Piccard. Before his attempt, the existing height record had been made in an aeroplane. Because his delicate instruments would have been unreliable in an aeroplane. Piccard chose a balloon.
Piccard and his assistant packed up the instruments inside the gondola, and then set about the work of detaching and packing those attached to the outside. After having secured the balloon in a rough and ready fashion, they improvised a camp for the night. Watchers on the ground had been growing more apprehensive all day, as it was originally expected that Piccard would land at about 2 p.m. At 7 p.m. the balloon was sighted from Garmisch and did not appear to be descending. Some anxiety was felt because of the limited capacity of the oxygen supply which the explorers were known to have taken up with them, and an aeroplane was sent up from Munich in pursuit of the balloon. The pilot located it, over the Tirol, but could not rise to more than half its height, and it was impossible to establish any communication with Piccard.
The villagers of Gurgl, however, had seen the balloon hovering over them, and early the next morning they saw it apparently balanced on a mountain ledge. They formed a rescue party and climbed towards the spot, and were greatly relieved to meet the stratosphere fliers on their downward journey.
It was difficult to remove the metal gondola from the glacier, and it remained there for some days. Ultimately, however, scores of soldiers, peasants and skiing enthusiasts managed to lower it over the glacier and tow it to Innsbruck. The envelope of the balloon was returned to Augsburg.
Official examination of the instruments showed that the balloon had reached an altitude of 51,775 feet - 8,000 feet higher than any human being had previously reached.
Until the end of the nineteenth century, scientists had believed that the atmosphere extended upwards for some seven miles only, and that above this there was nothing which presented anything of interest. As the height above the Earth increased, so they believed, the density of the atmosphere became less and less, until finally it tailed off into the vacuum of space.
The existence of the stratosphere, a region beginning some seven miles above the surface of the Earth, was discovered by a French scientist, Tessereinc de Bort, in 1899. During his experiments with sounding balloons he discovered that at a height of about seven miles temperature ceased to fall as height was increased.
ONE SIDE OF THE GONDOLA was coated with black paint, the other side being kept white. Piccard hoped that, with the help of a propeller at the end of a projecting arm, he would be able to turn the gondola round at will. A black surface absorbs heat and a white surface reflects it. The purpose of the black paint was to make it possible to control the heat inside the gondola by turning either side towards the sun. The propeller arrangement did not work, however, and Piccard and his assistant were forced to endure a temperature of 104° Fahr., while there was a temperature of 60 degrees below zero on the outside of their gondola.
Several attempts were made to reach the stratosphere in ordinary balloons, but most of these attempts ended in failure or in tragedy because of the imperfect equipment with which the would-be explorers were provided. The combined effects of low temperature, low pressure and lack of oxygen were too much for the daring pioneers who attempted to brave the mysteries of the upper atmosphere in an open basket. Before Piccard’s ascent “sounding balloons” carrying scientific instruments had provided valuable data concerning the conditions to be met. The average height reached by such balloons was about fifteen miles, but on one occasion a balloon reached an altitude of more than twenty-three miles, at which the temperature was found to be 60° Fahr. below zero.
There are many reasons for exploration of the stratosphere, the investigation of cosmic rays being one of the most important. Professor Piccard determined to enter the unknown region himself, and he profited by the experience of scientists who had collated data from the ascents of sounding balloons, and also from the unfortunate experiences of those who had tried to make ascents themselves. His was the first adequately equipped expedition into the stratosphere, and it rightly commanded world-wide admiration.
Professor Piccard said that he believed that the stratosphere was the future highway for world travel because of the complete absence of clouds and winds. Professor Picrard and others discovered that a pilot flying in the stratosphere during the day is always flying in the sunshine. At night a brilliant, starry sky will guide him. There are no clouds in the stratosphere, so that it never rains.
Piccard further discovered that, although there is no wind in the stratosphere itself, the wind changes as a balloon or aeroplane ascends. If the wind were blowing due east when a pilot began his flight or a balloonist his ascent, he would find that the wind would drop as he entered the stratosphere and would then change round to due west. Piccard also observed that there was a tremendous source of thermal energy in the stratosphere which, in his opinion, would in the future be harnessed and used as a source of power. Professor Appleton, in England, has since discovered that in the upper atmosphere there is a vast layer of intense heat, which he believes to be at a temperature of about 1,800° Fahr. Another extraordinary discovery about the stratosphere is that at a height of some forty miles there is enough hydrogen in the atmosphere to form an explosive mixture.
The primary purpose of Piccard’s first ascent was cosmic ray investigation, and he obtained results which were sufficiently interesting to justify the planning of a second ascent. The necessary funds were provided, as they had been provided for the first ascent, by the F.N.R.S. (Fonds Nationals de la Recherche Scientifique), which owed its origin to Albert King of the Belgians.
The original gondola had been badly damaged during its travels, and Professor Piccard designed a new one. This was made in Brussels and was taken to Zurich on a motor lorry. The new gondola was painted white all over because of the discomfort suffered by the occupants of the first gondola with its black surface pointing to the sun.
The second ascent was planned to start from Dubendorf aerodrome, near Zurich. A miniature rail track was laid for the special purpose of taking the gondola from the hangar to the middle of the aerodrome.
Conditions were favourable on August 11, 1932. The Swiss Military Air Force and Police were ready at hand, and the large ground staff took the balloon out into the field. At the last moment, an unfavourable weather report was received, and the flight was postponed. Six days later, however, another favourable period began, and the ground staff was mobilized on August 17. The balloon was laid out on the ground in the heat of the afternoon, and inflation was begun in the evening. Just as day was breaking the wind dropped, and the balloon was released at 5.07 a.m. on August 18. Apparently there had been a slight miscalculation of the desired amount of lift, and it was necessary to dump a small amount of ballast, after which the balloon made a perfect ascent.
A HUGE BALLOON was necessary for Professor Piccard’s ascent. Its capacity when fully inflated was 500,000 cubic feet - about ten times greater than that of the average balloon for work at normal heights. Piccard’s balloon weighed some 1,500 lb and had a diameter of 99 feet when fully inflated. The difficulties of inflating a large balloon are considerable. Although the weather may be perfectly calm at ground level, the enormous bag, pear-shaped when inflated, would reach high into that part of the air where there may be gusts of wind. On Piccard’s first attempt (September 1930) the balloon had to be suddenly deflated when it was nearly full, because of a fall in the barometer.
This second flight differed from the first in that the crew of the balloon - Professor Piccard and a pupil of his, Max Cosyns - suffered from intense cold. The gondola was sealed at an altitude of about 5,000 feet, just before sunrise. In less than half an hour the balloon had reached a height of 28,000 feet, and a few minutes later the temperature had dropped to 39° Fahr.
Professor Piccard’s log comments on the fact that he and his assistant were too busy with their scientific instruments to be able to look about them and admire the glorious views. They did, however, notice the Gross Gurgl Ferner glacier, on which their balloon had descended at the end of the previous year’s flight.
During the ascent a thermometer containing mercury broke and the mercury was spilt on the floor of the gondola. Mercury penetrates aluminium almost as quickly as acid. Piccard and Max Cosyns worked desperately to collect all the spilt mercury before it could eat its way through the thin shell of the gondola.
By 11.50 a.m. they decided that the time had come to make preparations for descending, and by 12.12 p.m. their instruments showed that they were at an altitude of 54,450 feet - nearly 300 feet higher than their previous record. Piccard and his assistant were suffering great discomfort, the thermometer within the gondola showing a temperature of 5° Fahr.
They began to release hydrogen - the escape valve was working perfectly this time - and started dropping at the rate of six feet a second. Soon the sun became so powerful that it began to dilate the gas again, and, in spite of the amount of gas that had been released, the balloon again began to climb. By 1.24 p.m., however, they were dropping at ten feet a second, and their new anxiety was that they might hit a mountain on the way down. They were then north of Lake Garda, in Italy.
The descent continued smoothly and uneventfully until, at 3.28 p.m., the balloon was at a height of 21,450 feet. A few minutes later the porthole was opened, and within an hour they saw that they would land on a broad plain within sight of Lake Garda. Almost exactly twelve hours after the start of the ascent, Piccard and Cosyns stepped from the gondola into a field some 150 miles from their starting place.
After having been nearly frozen to death more than ten miles above the Earth, the two scientists were overcome by the suddenness of the ground heat. They soon recovered, however, and it was apparent that they were to suffer no ill effects.
It was not until midnight that they were able to retire to rest. The scientific instruments had to be adjusted and carefully packed, but many of the observations did not yield positive results until afterwards. It was eventually found that the official record of the maximum height attained gave the figure of 53,152 feet. The cosmic ray observations were carried out between 9,000 feet and the maximum height attained, and the evidence obtained proved that the cosmic rays do not arrive from any particular direction. This was one of the important points that Piccard had hoped to settle. The other scientific investigations concerned measurements of temperature and barometric pressure; observation of the speed and force of the wind at various heights; measuring changes in the electrical conductivity of the air; determining the concentration of ozone in the upper air; and comparisons of sky, sun and Earth brightness.
Many other complex problems have been studied by other scientists who have made ascents since 1932, but Professor Piccard was the pioneer who made these ascents possible, and his own second ascent proved that stratosphere flights, properly equipped, could be quite uneventful and perfectly safe. The gondola used on the second ascent was shipped to Chicago, Illinois, where it was placed on view at the Exhibition of 1933. It proved to be one of the main centres of attraction among the scientific exhibits.
By ascending twice to heights never previously reached by a human being, Professor Piccard gained great distinction in the history of scientific achievement, and his work has since been carried on by many other scientists.
TESTING THE INSTRUMENTS in the gondola before the ascent. During the ascent the instruments and scientific apparatus for the study of cosmic rays were fixed on circular panels round the walls of the gondola, which was 7 feet in diameter and was built of an aluminium alloy.