OTL, the age of stratosphere balloons was short -- even shorter than the age of zeppelins. Basically we're talking about a decade. And the whole thing is half forgotten today.
But 75 years ago, it was quite something.
Here follows a long quote; feel free to skip ahead.
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"In 1927, aeronaut Captain Hawthorne C. Gray, of the U.S. Army Air Corps, ventured into the stratosphere. He set a U.S. altitude record at 29,000 feet (8,839 meters) on his first flight, and although he attained 42,000 feet (13,222 meters) on his second flight, it was not an official record, because he had to parachute out of his balloon as it descended to save himself.
"His balloon, Army No. S-30-241, was a 70,000-cubic-foot (1,982-cubic- meter) single-ply rubberized silk envelope coated with aluminum paint. Gray's three flights offered him the opportunity to test high-altitude clothing, oxygen systems, and instruments as well as set a new record. On his third flight in November 1927, he reached 42,000 feet (13,222 meters) again, but ran out of oxygen on the descent. He arrived on the ground with his balloon, but he was dead...
"Gray 's death underscored the central problem facing high-altitude balloonists... [t]o fly above 40,000 feet (12,192 meters) without a pressure garment or the protection of a pressurized vessel was to invite death.
"The 1930s saw a large number of flights into the stratosphere. Auguste Piccard led the efforts. He... considered the problem of oxygen deprivation to be no obstacle. A leading cosmic ray investigator, he needed to rise above the atmosphere to study it. Obviously, he would have to design a sealed, pressurized gondola.
"Using an apparatus developed by the Germans for use in submarines during World War I, Piccard built a gondola sphere 82 inches (208 centimeters) in diameter that weighed 300 pounds (136 kilograms). The gondola was designed to keep two people alive for up to 10 hours above 40,000 feet (12,192 meters). The apparatus released pure oxygen into the cabin while scrubbing and recirculating cabin air by filtering it through alkalai.
"Piccard also solved the problem of the lifting gas of the balloon leaking away as it expanded during ascent by using a balloon envelope five times larger than necessary to get off the ground. The lifting gas would remain inside the balloon envelope as it expanded, giving him enough lift to return safely to Earth as the gas cooled at night. His 500,000-cubic-foot (1,416-cubic-meter) gas bag, fully inflated, could have lifted a locomotive.
"On May 27, 1931, Piccard and Paul Kipfer climbed into the stratosphere in a spherical, airtight, metal cabin suspended from a specially constructed, hydrogen-filled balloon. This balloon, with a capacity of 494,400 cubic feet (14,000 cubic meters), reached an altitude of 51,783 feet (15,787 meters). The following year Piccard ascended to an even higher 53,152 feet (16,200 meters) with Max Cosyns.
"Inspired by Piccard's success, the Soviet Union flew the largest balloon built to date, at 860,000 cubic feet (25,353 cubic meters), with a gondola. The balloon reached a record 60,700 feet (18,501 meters) on Sept. 30, 1933.
"Not to be outdone, the United States flew the Century of Progress, whose team was headed by Auguste Piccard's twin brother Jean Piccard, with a gondola to a record height of 61,000 feet (18,592 meters) on November 20, 1933. The balloon carried two instruments to measure how gas conducted cosmic rays, a cosmic ray telescope, a polariscope to study the polarization of light at high altitudes, fruit flies to study genetic mutations for the U.S. Department of Agriculture, and an infrared camera to study the ozone layer.
"The next year on January 30, 1934, a Soviet balloon flew to 72,000 feet(21,946 meters), but it descended too quickly and the crew died.
"In 1934, the U.S. Army Air Corps again began to participate in high-altitude flights. Captain Albert W. Stevens piloted the Explorer I and Explorer II. Explorer I had a balloon of 3,000,000 cubic feet (84,950 cubic meters), five times the volume of the Century of Progress. The first flight of Explorer I climbed to 60,613 feet (18,475 meters) on July 27, 1934, but the balloon ripped. and Stevens, co-pilot Maj. William Ellsworth Kepner, and Orvil A. Anderson, operations officer, had to parachute to safety."
-- Pause to contemplate that one. Their balloon is sixty thousand feet up -- almost 20 kilometers into the sky. Then it *rips*. So they have to climb out of the falling gondola and parachute. All this with 1930s equipment. I would love to read an account of that trip.
Note also the advance of the technology. In seven years, we've gone from 70,000 cubic feet to 3,000,000.
"In June 1935, a Soviet mission climbed to 52,800 feet (16,093 meters) in a balloon. This was the first of many flights taken by the Soviets to systematically explore the upper atmosphere, emphasizing physics over records.
"Explorer II was the last high-altitude flight of the 1930s. It had an envelope of 3,700,000 cubic feet (104,772 cubic meters) and was the first helium balloon. Its sealed gondola kept the crew from freezing to death and their blood from boiling due to the low air pressure. On November 10, 1935, Explorer II reached 72,395 feet (22,066 meters), high enough to see the curvature of the Earth. Piloted by Anderson and Stevens, it set a world altitude record that would stand for the next 21 years.
"Their flight marked the end of the great era of human stratosphere ballooning. The enormous and heavy balloon envelopes had clearly reached the limits of rubberized fabric balloon technology, and a worldwide depression was setting in."
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Now. OTL this exploration of the stratosphere used a certain amount of WWI spinoff technology. But I don't think a simple high-altitude balloon was beyond the capabilities of the Belle Epoque. You need a suitably tough envelope, protection from the cold, and oxygen. That all seems doable. Rubberized envelopes could have been done in the 1890s; short-term chemical rebreathers were first developed around 1900.
Certainly the possibility was there. Two Englishmen, Coxwell and Glaisher, had briefly ascended to over 10 km in 1862. Remarkably, they survived, and set a record that would last until Captain Gray's ascent 65 years later. The POD... heck, I don't know. Some early airship developer gets a bug. Maybe altitude records become a source of national pride, like reaching the North and South Poles.
So, beginning in the 1890s, two or three nations start sending balloons 10 km high. Payloads are light, and the trips are short. The aeronauts will start off wearing crude pressure suits, probably adapted from contemporary diving suits, with simple insulation underneath. (Simple as in wool sweaters, probably. Temperatures will go down under -40, but the longest trip will be under an hour, so this is not completely daft.)
Now, this is going to be incredibly dangerous. Rips in the envelope; leaks in the crude pressure suits; failure of the rebreathing apparatus; anoxia; hypothermia. Or simply landing in the wrong place. High altitude balloons could catch fast high-altitude winds and end up very far away from their takeoff. OTL one high-altitude balloonist was killed when his balloon drifted out to sea; he landed safely, but then drowned -- his pressure suit became waterlogged and dragged him down.
But this is the Belle Epoque! Man against nature! National pride at stake! How high can we raise the Union Jack? We must not let the Germans beat us to the stratosphere!
So. By 1905, there have been several expeditions over the 10 kilometer mark. By 1910, at least two have ascended over 14 km (45,000 feet). There have also been a number of gruesome accidents, but never mind... the rivalry has captured the public imagination. By the eve of WWI, there have been several flights over 50,000 feet, and balloons have stayed aloft around the 30, 000 foot mark for several hours at a time.
And then the Archduke goes to Sarajevo.
Some thoughts.
1) Pure science. We know about the ozone layer a generation sooner, and that cosmic rays are cosmic. (OTL they were discovered in 1912, when a German scientist named Victor Hess took a balloon up to 4000 meters.)
Meteorology gets a shot in the arm. I have a mental image of some insane American with a Kodak Brownie trying to get a picture of a Great Plains thunderstorm from above.
2) Spinoffs. I think parachute technology comes earlier in this TL. Diving apparatus will be improved faster. Knock-ons for submarines too, I'm sure. Pressurized cockpit technology will be waiting for airplanes that can use it.
3) Military applications. This gets wacky, but hear me out. In 1914, no airplane could climb past about 12,000 feet. By the end of the war, the ceiling would be over 20,000 feet, but still... a balloon 8 or 10 kilometers up would be completely untouchable.
At 8,000 meters or 25,000 feet, with reasonably clear weather, you can see a hundred miles away. An aeronaut with binoculars, a wireless set and a rebreather can stay up for several hours. It's every general's dream: an untouchable eye in the sky.
-- Okay, not quite untouchable. A big balloon can easily rise at over 1000 feet per minute, so the ascents will be relatively safe: take off in the early morning, when no enemy fighters are around, and keep radio silence until you're at cruising altitude. Descents may be trickier, though... the enemy may have heard your wireless broadcasts and sent interceptors, high-altitude winds are unpredictable, and you may be running short on air.
So overall, the Stratonautical Service is not going to be a good insurance risk. One of those "either a Victoria Cross, or a wooden cross" sort of things. But it's wartime, and there are always young men willing to try something new and crazy.
I don't think this will make much of a difference on the Western Front. In the east, though, I think it gives a significant tactical advantage to the more technically advanced Germans.
What think you?
Doug M.