Cross the Atlantic!

Local Inventors race against time and weather to send the spirit of Knoxville across the globe in a ballooning adventure

A frantic call at 10 p.m. on Thursday, Jan. 3, alerts the core members of the UT Amateur Radio Club (UTARC) that, yes, the jet stream has dipped south, and that conditions are perfect to attempt to send a weather balloon across the Atlantic. It's an engineering feat that has never been pulled off successfully by private individuals.

The project, dubbed "The Spirit of Knoxville," easily conjures

images of vintage science fiction, like something out of Jules Verne or an old boyhood adventure novella. Right now, as our story continues on the tarmac of Downtown Island Airport on the south bank of the Tennessee River, the fates of Dan Bowen, Mike Coffey and a crew of ham radio enthusiasts, electrical engineers, and computer programmers—not to mention one rather large zero-pressure helium balloon with a 12-pound payload—are subject to the indomitable and crushing effects of pure probability.

"Sometimes it's a cliffhanger," Bowen says after hauling two helium tanks from his car. "We're not normally this last-minute, but we got a good jet stream."

He adds, almost fatalistically: "We are perpetually overeager to fly."

A small white sign with red block letters sits at the entrance to the main hangar. "Balloon Launch," it reads. Inside there's the gentle hum of two industrial heaters, and the crew's already at work. The balloon's stretched across the ground, completely empty. The airport closes at 11 p.m. They have just less than 30 minutes to get this thing into the air, and, of course, this isn't the most organized spectacle ever. "The balloon's out of the box" is yelled over to the guys who have been prepping the ballast.

Someone hollers, "Get the weight of the ballast box!"

11.75 ounces.

"I need help getting the strings tied around the payload."

"Carl? …Do you want to start rigging the box?"

"How much is it when the ballast's full?"

Five pounds, 13 ounces.

"It's 10:35. We're doing good."

They pump 300 cubic feet of helium into the balloon. "That's good helium," launch coordinator Greg Williams says to test the tank's contents. "How about them apples," his voice cartooning into a high-pitched squeak. The balloon finally begins to take shape, floating just above the ground like a plasticized jellyfish. "You guys might want to take it outside." It's 10 minutes till 11.

"Hey, Dan!—this thing's lifting!"

"It's supposed to."

"Huzzah," someone says in deadpan tone. They walk the Spirit of Knoxville (SNOX), flight No. II, out of the hangar for the first time.

TO CROSS THE ATLANTIC, YOU HAVE TO GO UP—and stop, to get into the jet stream," Bowen says. He's an impossibly thin tech-head, as comfortable explaining Boyle's Law as he is plugging lines of code into a compiler. When he speaks, his voice is measured, calculated, always reliant on total economy of language. "We have learned so much about weather that we didn't intend to," a brief, intentional pause, "very tedious."

The jet stream consists of high-altitude, narrow paths of wind that typically run at 100 to 200 mph. As a general rule of thumb, the jet stream's only good for crossing the ocean during wintertime. The window of opportunity opens from the beginning of December to March, and maybe continuing into early April. Usually the jet stream sputters along in isolated gusts, but during the colder months is when it's most likely to be blowing in a continuous stream.

"It's a river of high-speed air," Bowen explains, "going all the way across the Atlantic Ocean into Europe, or Africa occasionally."

Bowen, as the SNOX project coordinator, has a mantra; he'll recite it whenever the mood strikes. To briefly summarize the point of Spirit of Knoxville, he'll say: "We wanted to do something exciting, something that has never been done before."

It's an act of cavalier simplicity each time they launch a timid, beeping box of electronics below a balloon, into the uncertainty of weather patterns, hoping that it'll find the perfect path inside the harsh, frigid jet stream 35,000 feet above ground.

Early tests, which began launching three years ago, used a classic latex balloon, the exact same thing that the National Weather Service sends up nearly every day, averaging about 7,000 each year.

"The problem with a rubber balloon is that it's gonna keep going up and up until it pops, and there's really no way to resist that," says Carl Lyster. He builds radios and flight computers from scratch. He's a brilliant electronics engineer, and a steady hand with the soldering iron. He's not an electrical engineer by trade, though; it's just his hobby.

"We started doing these balloons about—almost three years ago," Bowen goes on. "Most everybody was doing up-and-down. Short flights, you know, up—pop—and then down."

One of these first flights, using two extra-large latex balloons, UTARC soared to a height of 115,942 feet, which was number nine for a short time in the record books kept by a trusted record keeper among amateur balloonists, Ralph Wallio of Iowa-based WØRPK. (His website,, lists the current record holders.)

There are a half-dozen or so groups experimenting with weather balloons. There's Bill Brown in Huntsville, Ala., who's generally considered to be the father of amateur ballooning. There's a group in Grosse Pointe, Mich. And Edge of Space Sciences (EOSS), a Denver, Colo.-based non-profit organization, has flown over 100 missions to date.

"Then there's that mystery group that came out of nowhere," Williams says. Near Space Sciences (NSS), a co-op of crafty science geeks from Richland Center, Wis., is a relatively unknown force to be reckoned with in the race to become the first privately-funded group to send a weather balloon across the Atlantic. The group contacted the Spirit of Knoxville crew to deliver a single message: "We're going to beat you."

But there's no formal competition. The first team to cross the Atlantic won't be welcomed by warmhearted Frenchmen and -women, like Charles Lindbergh would've. This is a quieter kind of fame, reserved for a few ham radio operators who, for reasons that seem as weird and esoteric as the bits of data that their radios intercept on a daily basis, continue to find new frontiers to explore. The last 20 flights have returned with stunning photographs of the Earth, which are among the few pictures of the heavens that weren't taken by the government. (Visit for more info and more photos. Visitors can sign up to receive an email alert before the next launch.)

To attempt a trans-Atlantic flight, however, UTARC needed a fresh design, something a little more versatile—and less expensive—than their latex balloons. One idea involved a superpressure balloon, which is basically a sealed plastic bag, much like a Ziploc bag. When pressure increases outside the bag as the balloon rises, the helium becomes so dense that it's no longer lighter than air, and the balloon descends until the pressure decreases and the balloon regains its lift. The idea could work, but for UTARC, the problem was crafting a balloon that could withstand such high pressures.

The next idea was more traditional: a zero-pressure balloon, similar in design but smaller in comparison to the 200- to 300-foot balloons that NASA uses to circumnavigate the Earth.

"We wanted to try this with balloons 30 feet tall, and between two and five feet wide," Bowen says, offering up an ad hoc boast: "We're aiming to be the first small balloon to go across the Atlantic Ocean."

AS THE ZERO-PRESSURE BALLOON GOES UP, the helium expands and is leaked through a hole in the bottom of the bag. To keep it at a steady altitude of, say, 35,000 feet, smack in the middle of the jet stream, the onboard computer routinely squirts out precisely measured amounts of denatured alcohol, and the balloon rises. With a ballast of five pounds of denatured alcohol, the SNOX flights are designed to stay in the air for nearly five days, should the onboard electronics work correctly.

"[The zero-pressure design] really spurred us on in thinking that we were close to a solution," Lyster says. But building a functional zero-pressure balloon isn't exactly an easy task. As luck would have it—and in this line of work, sometimes luck is all you have—Mark Caviezel's design firm, Global Western Industries, had a zero-pressure balloon that they were anxious to test in the field.

"They were perfect, actually," Bowen says. "They could haul the maximum amount of weight that we can legally send into the sky. Without going over 12 pounds, we can pretty much do anything we want."

At the same time, no one's eager to push his luck too far.

"We typically call the local McGee-Tyson Airport," Bowen continues, "and tell them that we're about to launch. They say, ‘We've got your mission on file here, go ahead.'"

Once, as they were prepping for one of their early missions, one that was never designed to be trans-Atlantic, UTARC received a call from the Atlanta Center, which controls the high altitudes over the entire Southeast. They had seen the report that was filed to announce the balloon flight, which is called a "Notice to Airmen," which is standard operating procedure. The report, unfortunately, had been filed incorrectly. Instead of a weather balloon coming up to 40,000 feet, the Atlanta Center was under the impression that there would be a tethered balloon at 40,000 feet.

They wanted to know why in the hell there would be a balloon attached to a tether at such a high altitude, next to an airport. The project was explained, as artfully as one can probably do over the phone, and the man from the Atlanta Center said, "I still don't like what you're doing, I don't like how this came to my attention, I'm not going to approve it."

Bowen explains the situation, "I very politely had to figure out how I was going to tell him that he didn't have to approve this." Under existing laws, so long as the payload is under 12 pounds, UTARC has few restrictions when they send a balloon into the sky. The National Weather Service has been launching balloons for the past 40 years, and these weather balloons have never affected air traffic.

Later, a supervisor from the Atlanta Center called with more questions, and more yelling. He said, "I'm not going to approve it, and I cannot deny it, but that's about all I can tell you guys at this point."

That's the way it goes for amateur ballooning. "About 20 percent of the time somebody has a conniption over it," Coffey says. Mike Coffey, the bespectacled computer whiz who wrote a program that predicts the position of the jet stream, has a quiet, unpretentious demeanor, and his subtle dark humor is often a welcome reprieve from the gobs of tech-speak that's parlayed among members of UTARC. A single tank of helium, for instance, can cost anywhere from $75 to $85 due to a worldwide helium shortage. The Department of the Interior has even made an announcement on NPR asking faithful listeners to reserve helium. Coffey laughs:

"We have a strategic helium reserve, to keep the Goodyear blimp afloat during times of war."

The SNOX II, after it finally took to the sky a few minutes before midnight Jan. 3, never made it into the jet stream. Instead, it meandered at random before coming to a gentle stop a few miles north of Island Home. The balloon lurched slowly upwards, lumbering awkwardly at first, before it finally settled into the wind. It seemed graceful at that moment, as it took its time floating out of sight.

"People will call to report an alien sighting."

"We've got a good relationship with the FAA——"

Back at 401 East Stadium Hall, at the UTARC office in the bowels of Neyland Stadium (nickname: "The Shack"), the crew anxiously checked the GPS tracking data for the balloon. They weren't getting much good news, and just a little under an hour into the flight, the balloon came crashing down, onto a telephone line in a North Knoxville neighborhood.

Several things went wrong with SNOX II. The most pressing factors were the time constraints. "We were lured by that siren song of a good jet stream," Bowen waxes poetic. One unforeseen problem was the heat coming down from the hangar's overhead heaters. The helium was thus heated while the balloon filled, creating the illusion of much greater lift. Outside, in the freezing cold, the lift was bound to decrease dramatically as the helium cooled.

"Under normal circumstances," Bowen continues, "we would've thought of that."

They estimate that the temperature dropped about 60 degrees when it was taken out of the hangar. That drastic drop in temperature could cause the balloon to lose 10 percent of its lift. As a result, it only flew to about 800 feet above ground level, making a short trip across the city.

FOR UTARC, FAILURE AND STRANGE ENCOUNTERS with colorful people have been a matter of course. Three years ago, while out scouting potential launch sites, they found a field near Watts Bar Lake. The field, located within plain sight of the Watts Bar nuclear power plant, was an idyllic setting for a launch. There was even a windsock staked into the ground. Conditions seemed, well, just about perfect.

At least until a white pickup drove into the field and came skidding to a stop. The nuclear plant security officers immediately informed their superiors that there were some suspicious persons in the area and, what's worse, they had a map.

Escorted to the plant, they met with the plant supervisor, who was particularly interested in the map, which was just an el cheapo roadmap from a convenience store. It was confiscated, as a precaution.

"We trespassed," Bowen says. "It wasn't marked though."

"It was just a beautiful field with a road leading into it," Coffey chimes in. No one ever explained why the map was such a red flag. A few months later, the crew returned and launched a balloon in a field on the opposite side of the lake. The nuclear plant was still in plain view.

"Everything we're doing is perfectly not described by any law," Bowen explains.

Flight No. 7 of the early latex series ended up in Irwin, Tenn., for a month and a half before it was eventually shot out of a tree with a potato gun. The sheriff's office in Irwin had been notified, because one concerned citizen had seen the payload's parachute engage as it fell towards the ground. It was reported that, perhaps, a jet fighter had gone down.

When a UTARC recovery crew drove to the crash site—a group of guys with ham radio equipment, headphones, and cars spiked with antennas—the local authorities suspected that these radio enthusiasts were, in fact, drug runners. And so it goes.

Then, there are the perfect flights, when everything just happens according to plan. During a mission to test their zero-pressure balloon's ability to hold a constant altitude, it flew over Kentucky and into West Virginia before the balloon finally descended after a flight across the U.S.A. At last, it seemed like this just might work.

By Dec. 1, 2007, they hoped to have a balloon ready for a trans-Atlantic flight. SNOX I was launched on the first day of December. Dubbed the SNOX I, because it was the first launch that was designed to purposefully attempt a trans-Atlantic voyage, the balloon flew about 600 miles, splashing down near the Bahamas.

The final transmissions of SNOX I were completely garbled, incoherent data, as the salt water began to leak in. The last thing anybody heard was a long beeeeep, and that was it.

"It was amazing that we could build something, on our workbench, and it would go out almost to the edge of space," Williams says.

And Bowen adds: "We wanted to see if the Earth is round. We wanted to see if Space really is black."

The Spirit of Knoxville's past failures, such as SNOX II, were just steppingstones. Back at The Shack, it's business as usual.

Scattered about—in various stages of construction—are the the large circuit boards for the next flight computers, a few two-liter bottles that'll be crafted into new ballast containers, and old, seemingly Flintstonian radio equipment. The machines crackle and buzz, occasionally picking up a brief piece of coherent data.

A few books fill their bookshelves—A Brief History of Time, Amateur Radio Today, How Business is Done in Japan, The Radio Amateur's Satellite Handbook, Fundamentals of Gas Turbines....

There are also the remains of pasts flights, pre-SNOX, that were recovered by UTARC. The payload for flight No. 7, the one that was caught up in Irwin for so long, sits on top of a filing cabinet, with a hole about the size of a potato in the side, caused by shooting it out of a tree near the Nolichucky River. The shot was perfect, missing the on-board flight computer by just a few inches.

"We'll keep launching until we make it," Bowen says. It's now a quiet Sunday afternoon, and Bowen's carving into a piece of Styrofoam. He's prepping the new ballast chamber. A few weeks earlier, during a launch on Jan. 14 that had the luxury of time on its side, the crew worked at an easy pace before lifting off at Downtown Island Airport. That balloon, SNOX III, went into the skies without much ceremony, and without any apparent glitches. They tracked its initial progress, and everything seemed to be on target.

"We had a very unusual failure with that one," Bowen recalls. "We had a GPS failure, or something in the line of the GPS signal failed. It'd never happened to us before."

SNOX III flew wonderfully, but the only data that they received seemed to indicate that the GPS had somehow failed.

UTARC tracks who's receiving those signals as the balloon flies along the path of the jet stream. As SNOX III went eastward, they could home in on its path each time a station within 200 miles of the balloon picked up its signal.

They predicted that it eventually dropped somewhere in the ballpark of 500 miles off the coast of Newfoundland, because it could never be alerted to ballast properly.

A few brief blogs from Jan. 15 tell the story: Currently it seems to be near Raleigh, N.C. It transmits a message every 5 minutes, but it can't tell us where it is.

Later that day, what looked like bad news was confirmed: The balloon has gone out to sea, likely landed at sunset today. We will analyze this one, and carefully, but quickly, build SNOX IV.

Every six hours the National Weather Service sends out a 250-megabyte file. This data gives predictions in weather patterns at specific latitude and longitude coordinates. Interpreting this data, under ideal circumstances, gives UTARC 48 hours notice when they might be able to slip into the jet stream. Other amateur balloon clubs are in a better place, geographically speaking, to catch the jet stream. Here in Knoxville, the next SNOX launch may come at any moment.

"We are not very optimally situated for this adventure," Bowen says, "but we can't afford to move."

Today, Lyster's at home, cloistered in his workshop to work on the payload's transmitter. Bowen and Coffey test the new flight computer. A steady flow of Morse Code indicates that it's working just fine. By inputting GPS coordinates into the flight computer, Coffey simulates a flight across the Atlantic. It's still just a dream, though, an opportunity to do something that's never been done before.

University of Tennessee film student Chris Heggen has been documenting UTARC's progress over the last couple of years. He's slogging through hours of video, and the result is a simple, peaceful moment of beauty, as the world is captured from onboard a weather balloon. From Knoxville of all places.

Circle Modern Dance's artistic director, Joy Davis, is considering choreographing a dance to commemorate the Spirit of Knoxville. She's asked about the possibility of using balloons that are capable of lifting a dancer for at least a few seconds.

Jen Rock, who plays guitar in local psychedelic four-track outfit, Deek Hoi, plans to compose music inspired by the videos filmed by some of the early missions. It'll be part of her latest group, New of the Moon, a multimedia art project.

"I'm looking forward to getting some sleep," Coffey says outright. "I'm sure we're gonna be on ‘News of the Weird,' right between the 450-pound lady and whatever else."