On the morning of May 27th, 1931, a  physicist named Auguste Piccard and   his assistant loaded themselves into a  strange contraption of his own design:   an airtight metal sphere attached to a balloon.

The two men had told the groundcrew  they’d be back around noon,   before lifting off and disappearing into the sky. But hours after the deadline,  they still weren’t back.

Two airplanes were sent after the balloon. But each had to abandon course. With the oxygen supply presumably exhausted and  the balloon drifting aimlessly over the Alps,   onlookers could only assume  the scientists were dead.

But, they were very much alive, trapped  some 15,000 meters above the Earth. They had managed to survive one catastrophe  after another, and there were still more to go. Because spoiler alert: they  survived the whole thing.

Their flight to the stratosphere may have  been a disaster, but it was humanity’s first. And in the process, they helped solve  one of science’s biggest mysteries. [♪ INTRO] In the early 1900’s, scientists began to suspect something weird was  happening to Earth’s atmosphere. Thanks to folks like French  physicist Henri Becquerel,   they already knew that pretty much  everything on Earth is quietly and   constantly being peppered by low  doses of high-energy radiation.

Don’t worry, a typical yearly dose is like  20 times below general exposure limits. Scientists just call it background  radiation at this point. But at the time, we didn’t know exactly  where all this radiation came from.

Some of it, scientists would learn,   came from radioactive elements that just  naturally exist in the rocks beneath our feet. Elements like radium and uranium. But “some” isn’t “all”.

And in the meantime, something  weird was happening in the air. To understand what was going on, you need to  know that radiation can be blocked by air. It’s not immediate.

It’s not like a big lead shield. But generally, the farther away you  go from the source of the radiation,   the more of it gets absorbed by  the molecules in our atmosphere. So if all the radiation came from rocks and  buildings, and if you were able to go way,   way up into the sky, the radiation levels  should go down in a predictable way.

I’m simplifying a bit, but that is the gist. However, in 1910, a Jesuit  priest named Theodor Wulf   carried a radiation counter up the Eiffel  tower and got some weird measurements. He’d done what he needed to: put a  lot of air between him and the ground.

And the radiation levels did go down,  but not as much as they should have. Assuming his numbers were right,  there were a couple of explanations. Perhaps up until that point, all the physicists   had gotten something wrong about  how air and radiation interact.

That was pretty unlikely, but the other  possibility seemed equally strange: A second, unknown source of  radiation pushing the numbers up. A radiation source in the atmosphere itself. But were Wulf’s numbers right?

There were quibbles with his findings,   like if he’d accounted for the metal in the  tower, so his data were mostly just ignored. Still, they hinted we were missing something. And if we were going to figure  out what that something was,   we needed a way to go higher  than the Eiffel tower.

A lot higher. In the 10th century, a scholar and polymath  named Abbas ibn Firnas tested a homemade   glider by jumping from a minaret in  Spain, with admittedly some injuries. Others followed suit with their  own gliders and parachutes.

But these were all more “falling  with style” than true flight. China is reported to have experimented  with human-lifting kites in the 1200’s. But let’s jump forward to 1783, when  the hot air balloon came onto the scene.

Inspired by toys such as sky lanterns,   these vehicles took advantage  of the fact that hot air rises. People would also eventually experiment with  lighter-than-air gases, like hydrogen or helium. And these really took off,  if you will pardon the pun.

Within 10 years, balloons were  being used by some militaries   to get a bird’s-eye view of the battlefield. For example, it’s reported that,  during the American Civil War,   the Union army would send one-to-five people  up in balloons as high as 300 meters, using   signal flags or telegraph wires to communicate  what they were seeing and help aim artillery. These balloons were usually anchored  to the ground, although there was one   incident where a general decided to try it  out for himself…only for the ropes to snap.

He then found himself drifting over the  Confederate army, who upon seeing an enemy   general just hanging out above them,  started taking potshots at his feet. Also, fun fact, Jules Verne, the writer  behind 20,000 Leagues Under the Sea,   wrote a sequel that starts with POWs escaping  a Confederate camp in a hydrogen balloon. The plot goes on to be a kind of cross between  The Swiss Family Robinson and the TV Show Lost.

Anyways, while the military was doing their thing,   scientists also became enamored  with these new balloons. Just a year after the first flight in  1783, scientists were going up to study   the atmosphere as well as things  like the Earth’s magnetic field. Which brings us back to our story, and  the weird radiation in the atmosphere.

It’s 1911, and a man named  Victor Hess was following   the same logic that sent Wulf up  the Eiffel tower the year before. He took an open-gondola balloon more than  one kilometer into the sky, and found that,   once again, radiation levels didn’t  decrease the way everyone expected. Wulf, it seems, had actually been onto something.

Subsequent flights by Hess and  others suggested that, even at   altitudes as high as five kilometers,  radiation levels actually increased. Where could this radiation be coming from? If it wasn’t the air itself…well, there was only  one thing higher than the atmosphere: Outer space.

In fact, we’d eventually start calling  this mysterious radiation cosmic rays. But other scientists pushed back, suggesting that   problems with Hess’ instruments  were to blame for his results. Over the next few years, the scientific  community went back and forth on the issue.

Measurements taken at even higher altitudes  could help figure out who was right,   but there’s only so high an  open-air gondola could go. Airplanes and uncrewed balloons could go higher. But some scientists still balked at the data,   suggesting those balloons  also had instrument errors.

Scientists needed the kind of  quality data that could only   be provided by manually-operated  instruments, not automatic ones. But they needed it from altitudes no human  had ever successfully reached before. Enter, Auguste Piccard.

Born in Switzerland, Piccard entered the  world as just one of a huge family of nerds. His father was a professor of chemistry. And growing up, Piccard and his twin brother  Jean both loved reading stories by Jules Verne.

And Piccard loved balloons. He and Jean would make hot air  balloons out of paper while growing up. And when he was a bit older,  Piccard actually joined a group   called the Swiss Aero-Club where he  learned practical ballooning skills.

He also served in the Army as part  of the observation balloon corps. Besides balloons and adventure, Piccard…being the   son of a university professor…had also grown  up hearing about those strange cosmic rays. He decided one of his life goals  was to investigate them himself,   maybe even figure out a way to  harness them as an energy source.

So perhaps unsurprisingly,   Piccard became a professor of physics  at University of Brussels in 1922. Four years later, Piccard discussed with  his twin…who also had become a scientist,   and moved to the United States…the  idea of a flight to study cosmic rays. In order to do so, Piccard would  need to collect data from a region   no scientist had successfully  reached yet: the stratosphere.

The stratosphere is part of the Earth’s  atmosphere, and was first discovered in 1902. Its height depends on your latitude, from  about 7 kilometers up right at the poles,   to about 20 kilometers near the equator. It sits right above the layer of the  atmosphere we live in, called the troposphere.

And unlike the troposphere, temperatures  tend to go up as you ascend. The stratosphere has a lot of ozone, very little  water, and basically no conventional weather. No rain or snow, and no clouds except  rare ones above the planet’s poles.

Like, imagine being so high up, you could look   down and watch entire hurricanes  and thunderstorms pass beneath you. That sounds awesome, as in the  original meaning of the word. Not like a hot dog with a bacon on it.

Now the stratosphere is far above the  death zone, where the air becomes so thin,   and so deprived of oxygen,  that humans cannot survive. But Piccard believed that  if he could get up there,   he could find new data on his beloved cosmic rays. If they really did come from outer space,  this would allow him an opportunity to   study them when they were “fresh”, so to  speak, having penetrated only a little   of the Earth’s atmosphere before the  air could absorb nearly all of them.

And beyond the science, there was still  that romantic, Jules Verne-style energy. Piccard wanted to show the world  that the kind of amazing feats he   read about as a boy were indeed possible,  and encourage the burgeoning air industry   to look to the high atmosphere  as a possible realm of travel. So he began to design and build himself a balloon.

Financed by the newly created Belgian  National Fund for Scientific Research,   Piccard added two key innovations  to his balloon over existing models. The first was an invention that  would dramatically save on weight. Instead of having the balloon  surrounded by netting,   he’d build the support for his  gondola into the balloon itself.

The second, and arguably more important one,   was an airtight, spherical aluminum  gondola, about 213 cm in diameter. Picard himself was 198cm tall,  so, for our American audience,   the gondola was 7 feet in  diameter and the man was 6’6” Inside the sphere, oxygen would  come not from the atmosphere,   but from bottles of ultra-cold liquid oxygen  to be opened and tipped out as needed. It would then instantly boil, since the  boiling point of oxygen at a standard   atmospheric pressure is like -183 degrees Celsius.

In the meantime, any exhaled carbon dioxide  would be removed via alkali scrubbers,   devices that draw the dangerous gas  out of the air via chemical reactions. Piccard took the technique from  German submarines at the time. Thanks to the controlled conditions  inside the air-tight gondola,   Piccard would not only be able to survive the  dangers of the stratosphere, but could also   bring up instruments so sensitive they could  only normally be used inside a laboratory.

Not in the field. And once the balloon was built, Piccard just  had to wait for an opportunity to use it. In 1930, an attempt on September  14th was canceled due to bad weather.

But the following May, things were looking up. The weather the preceding days  had been quote-unquote “perfect”,   per reporting by the New York Times. And on the night of the 26th,   at 11 PM, Piccard had his crew start  filling the balloon with hydrogen.

He hoped to lift off from the Riedlinger  balloon factory facility in Augsburg,   Germany early the next morning. Joining Piccard would be  his assistant, Paul Kipfer. But even before they left the  ground, problems started to occur.

Though the weather had been good before,   as the balloon started to fill, a wind  kicked up and knocked everything around. A bunch of stuff got slightly battered,   including the seal around an instrument  built through the wall of the gondola. But nobody noticed at the time, and things  seemed like they were all working correctly.

Piccard and Kipfer ended up lifting  off at roughly 3:55 that morning. It looked for a second like the balloon  might hit the factory roof on liftoff,   but they managed to avoid it. And began to rise.

And rise. And rise. They were expected to land  about eight hours later,   around noon or the early afternoon, somewhere  between the cities of Freiburg and Basel.

But just in case, Piccard packed double the oxygen  he and Kipfer would need for that length of trip. This decision turned out to be a good one, because  as the two men were ascending into the atmosphere   and starting to unpack and set-up the instruments,  Piccard started to hear a hissing sound. Remember that broken seal in  the wall that nobody noticed?

Air from inside the gondola was  being sucked out through it. The airtight gondola that  would let them survive the   low-pressure atmosphere was no longer airtight. Piccard was able to stuff the leak with a  mixture of vaseline and loose cotton waste.

But they were rising fast, and by the  time the leak had been patched up,   they were already in the stratosphere. In fact, the whole trip up  only took about half-an-hour. Once at the top, things must have been looking up.

Sure, the leak was unfortunate,  but that was taken care of. And now they could marvel at what they’d achieved. Later, Piccard would write: “The beauty of this  sky is the most poignant thing we have seen:   it is sombre, dark blue or violet, almost black.” He described looking down and seeing the  whole countryside below him, the snowy   tips of mountains revealing themselves  bit by bit above the foggy clouds below.

There had been a few hiccups, but their trip  up to the stratosphere had been a success. Piccard and Kipfer deployed their instruments  and started to take some measurements,   counting how many cosmic rays they  were seeing pass through their cabin. Their trip down, however, would not be as easy.

After a bit of time, Piccard  went to release a bit of gas. Piccard and Kipfer’s intention had been to  take measurements at many different heights,   to build out a whole map of different  radiation levels along their journey. And to do that, they’d built a valve  into the balloon that they could use   to release just a bit of gas at a time, which  is how they planned to control their descent.

But when Piccard went to pull on the cable  that opened up the valve, it wasn’t working. Perhaps that early wind had caused the  cable to get tangled up in something. After more fiddling with it... the cable broke!

What must it have felt like, seeing the only  way to get back home just dangling there? With no way to control their descent,   Piccard wrote in his notebook:  “We are prisoners of the air.” We’ll be back with more of  this wild story in a minute. But first, a quick ad.

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Now, everything that goes up must come down. And as scientists, Piccard and  Kipfer knew there was an out:   Gases expand when heated,  and contract when chilled. With the Sun outside heating their balloon during  the day, the gas would stay heated and stay aloft.

But as the Sun set, the gas inside the balloon  would start to condense and lose buoyancy. The problem was that they would have to wait  the hours it would take for that to happen. All on a limited supply of oxygen.

Oh, and the air leak reappeared, too. “So the struggle for life began  again…” Piccard would later write. Unfortunately, that wasn’t  the end of their bad luck. To make things worse, at some point a barometer   inside the gondola shattered and  spilled some mercury on the floor.

Mercury can chemically react with aluminum,  and might have started to eat a hole through   the gondola’s floor if it weren’t for a  thick layer of paint coating the inside. Nevertheless, mercury isn’t exactly  a good thing to have just, like,   splashing up around your feet as you walk around. So Piccard turned into Angus MacGyver once again.

Ask your parents. He took a hose connected to the atmosphere  outside and – since the outside had so little   air pressure – when he opened it up, it was kind  of like opening up a tiny airlock to outer space. The hose was turned into a makeshift vacuum.

A bit of their oxygen was lost, but most  of the mercury was sucked right out. Not all of it, but most. Which leads us to the next problem  they discovered: They had no water.

They were supposed to have two large bottles of  drinking water to split between the two of them,   but instead they discovered  they only had one small one. There was some water that had collected at  the bottom of the gondola from their breath,   and they could have theoretically used that  to quench their thirst, but that stuff was   full of dust and the rest of the mercury  that Piccard wasn’t able to vacuum out. It was bad, but their thirst  was going to get worse.

Because by pm, the mechanism meant to  regulate the temperature inside the gondola broke. The gondola’s exterior had  been painted black on one side. Darker colors absorb more of the  sun’s energy, so if it got too hot,   Piccard simply had to rotate the whole thing so  the shiny aluminum side pointed toward the Sun.

And vice versa. But when they went to test  it, the motor wasn’t working. So the temperature went up, and up...

At one point, the inside of the gondola  reached over 40 degrees Celsius. Piccard described it as, “unpleasant”. Eventually, around 2 PM, they started to descend.

But it was slow going. So let’s check in on the ground. Piccard and Kipfer were  supposed to have landed by now,   and there was no radio to communicate  with them to learn what went wrong.

Two airplanes were sent from Germany  to try and make contact with Piccard,   but they couldn’t reach the necessary altitude. So by the evening, everyone on the ground was  totally convinced the scientists were dead. A reporter from the New York Times wrote that,   quote, “even the makers of the  stratosphere balloon had given up hope”.

Back in the sky, the balloon  was now slowly descending,   and as the Sun went down, the  heat was finally relenting. But this only led to another new  problem: At first it was too hot. Now, it was too cold.

It got so cold, in fact, the moisture in the air  started to freeze to the walls and instruments,   with Piccard comparing it  to snow inside the cabin. Sounds miserable, but at least this  kind of solved their water problem. They could scrape frost off the inside of  the gondola, caused by their own breath!

This is how they had to exist for hours. But, eventually, their rate  of descent started to pick up. And around 8 PM, they returned to the troposphere.

They were right that the cool of the  evening would get them back to Earth. But they still had to be careful. While they were headed in the right direction,   that broken valve meant they couldn’t  control how fast they were descending.

They could jettison some ballast  to make sure they didn’t crash. That is to say, throw stuff off the side. But if they lost too much weight, the  balloon would start to rise again.

Meanwhile, Kipfer had been keeping  a close eye on the barometer. And when they hit an altitude of around  4,500 meters, he called out that the air   pressures inside and outside the  gondola had finally equalled out. After 17 hours of being sealed inside  the gondola, the two scientists could   finally open up the portholes and stick  their heads out to breathe fresh air.

By this time, they only had 1 hour of oxygen left. Without Piccard’s foresight  to double up “just in case,”   they would have suffocated to death hours ago. He would later write: “Above us, the starry sky.

Beneath, the high mountains, snow and rocks. The moonlight was magnificent.” They saw  distant thunderstorms and the mountains,   the peaks of some already  towering above them as they fell. The two men weren’t done yet, though,   and Piccard knew the next few  minutes were going to happen fast.

They were going to land  somewhere in the mountains. It was probably going to be a  rough landing no matter what,   but if Piccard and Kipfer were careful,  they could avoid smashing into a field   of jagged, bone-breaking rocks, or  disappearing down a glacial crevasse. At one point, they even bounced off a steep  snowfield, but Piccard kept his nerve.

Eventually, he saw a smooth stretch  of glacier beneath the balloon. He pulled a ripcord, releasing the  entirety of the balloon’s gases. And at roughly 9 PM, the balloon finally  came to rest on the Gurgl glacier in Austria.

Piccard later said, "We jolted slightly  when the gondola scraped over the glacier,   but the balloon was scarcely damaged.” Far away from any rescue, Piccard and Kipfer  wound up spending the night on the glacier,   using balloon material as a blanket. In the morning, they cooked themselves a  meal of “arrowroot mixed with glacier ice”,   before starting the hike down  to the village of Obergurgl. And halfway through their journey,  they were caught by a rescue party   who’d seen the balloon go down,  led by the village schoolmaster.

Piccard and Kipfer ultimately  arrived in the village at 5 PM. They then made their way to Brussels,   where they met with politicians,  students, even the king and queen. Not to mention their families.

And eventually, they went back up and  retrieved the balloon from the glacier as well. So what happened after? Well, first off, Piccard and  Kipfer’s altitude record of   15,781 meters was accepted by the Swiss aero club.

But what about the science? What about Piccard’s beloved cosmic rays? Unfortunately, between all of the hullabaloo, the  scientists only took one radiation measurement,   right at the peak of their flight  at just shy of 16,000 meters.

After some re-calibration on Earth, Piccard found  the data did match what Victor Hess had predicted. Cosmic rays really were coming from outer  space…according to that one measurement. If you’re a good scientist, that isn’t  enough to say anything definitive.

But as far as single data points  go, it was a tantalizing one. Piccard would fly again the following year,  going even higher into the stratosphere. Thankfully, the flight was much more  boring and yielded much more data.

Within a few years, thanks to Piccard  and other balloonists…as well as   improvements to uncrewed balloons…  a conclusion was finally reached. Today, we know that most cosmic rays are  subatomic particles that get shot across   the universe from things like supernovas at  nearly the speed of light, only to crash into   our atmosphere where they explode in a shower  of gamma rays and other high-energy particles. As for Piccard, he dreamt that his  success would encourage nearly all   future air traffic to reach the stratosphere.

That future has…not arrived yet, if it ever will. We still tend to stick to the troposphere,   but some modern airplane trips may go through  the very lowest bit of the stratosphere. Eventually, and apparently not  satisfied with conquering the skies,   Piccard turned his sights to creating an  airtight vessel that goes down: the bathyscaphe.

In 1953, he and his son Jacques took a  bathyscaphe to a record depth of 3,150 meters. And as inspired as Piccard was by  the likes of fictional explorers,   he too became the inspiration for others. The Professor Calculus character in the comic  series Tintin was explicitly based on him.

And yes, there is a certain Star  Trek captain who shares his surname,   with a slight shift in spelling. Although it isn’t quite clear from  the historical record which, if any,   member of the Piccard dynasty  Jean-Luc Picard was named after. So that’s the story of why humanity’s first  visit to the stratosphere was kind of a disaster.

A scientific expedition with lofty goals,  only to be spoiled by a loss of control,   emergency leaks, crash landing, and what  must have seemed like a return from the dead. But hey, no one died. And even though Piccard wasn’t able  to accomplish that much science on   the trip, he still helped solve a  decades-long scientific mystery… … and proved that the kinds of expedition  he dreamed of as a kid were indeed possible. [♪ OUTRO]