Baumgartner's jump
Illustration by McKibillo

The Supersonic Man

Austrian daredevil Felix Baumgartner plans to jump out of a balloon gondola 23 miles above the earth, breaking the altitude record for skydiving and becoming the first free-falling human to reach the speed of sound. Dangerous? Only if his parachutes fail, he's killed by shock waves, or he starts spinning so fast that his brain snaps loose from its st

Baumgartner's jump
Mary Roach

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The PERRIS SKYVENTURE vertical wind tunnel is a hurricane in a can. Inside the core of a cylindrical building that looks like an air-traffic-control tower, air driven by huge fans whooshes upward at 100-plus miles per hour. The tunnel probably isn’t the tallest building in Perris, California—a sprawl of malls and tract homes a couple of hours east of Los Angeles—but it feels like it. Near the top, two sets of doors open onto the column of wind. Customers walk through the doors, lean into the air as they spread their arms and legs, and are lifted off their feet. It’s the sensation of free fall without the danger or rush: skydiving with its balls removed. If it’s your first visit, a staff person helps steady you—in case you drift upward and panic or start bouncing off the walls like an air-popped kernel.


Baumgartner Baumgartner in California, test-driving the suit he'll wear during the 120,000-foot skydive.


Baumgartner Baumgartner in Salzburg, Austria


Baumgartner Fine-tuning the suit at the David Clark Company

Baumgartner's jump

Baumgartner's jump Illustration by McKibillo

Today is Felix Baumgartner’s first visit to SkyVenture, but no one will be holding on to him. A photogenic 41-year-old Austrian, Baumgartner is a high-profile professional stuntman and BASE jumper. BASE is an acronym for “buildings, antennae, spans [meaning bridges], and earth [cliffs],” and Baumgartner has parachuted off all of these many times. You can go on YouTube and watch him jump off the outstretched right arm of the enormous Christ statue in Rio de Janeiro—or, more prosaically, the roof of the 20-story Warsaw Marriott. For most of his stunts, Baumgartner wears a skydiver’s jumpsuit. In the Marriott video, he’s dressed in business casual. He did this to pass through the hotel lobby without arousing suspicion, but as you watch him walk to the edge of the roof in his tie and dress shirt, the impression you get is that jumping off buildings is, for Baumgartner, just another day on the job.

THIS EVENING FINDS Baumgartner dressed like an astronaut. He’s in Perris training for his role in the Red Bull Stratos Mission, an elaborate, expensive, and very risky project sponsored by the Austrian energy-drink company. The mission’s aims are twofold—part record-breaking athletic feat, part serious science. I’m here because I’m interested in the aero­medical-research side of things.

During the Stratos jump, Baumgartner will test a modified emergency-escape space suit designed by the Massachusetts-based David Clark Company, makers of protective suits for test pilots and astronauts since the early days of jet flight and space exploration. Starting in 1986, when the Space Shuttle Challenger exploded 73 seconds after liftoff, astronauts have been required to wear pressurized, oxygen-fed suits not only while spacewalking but during launch, reentry, and landing—the most dangerous parts of a flight. Baumgartner will wear the test suit to stay alive during a “space dive” from 120,000 feet up, or roughly 23 miles. Though that height doesn’t technically qualify as space—true space, with its almost complete absence of air, starts at around 62 miles up—it’s close. Atmospheric pressure is less than a hundredth of what it is at sea level.

The jump is slated for late summer or fall in an undisclosed locale—most likely in New Mexico—that Red Bull is treating like an atomic secret. Wherever and whenever it happens, it will provide engineers with hard-to-come-by information about the behavior of a falling body in a pressurized suit in extremely thin air, along with data on the reactions of that body to transonic and supersonic speeds. This is not information with everyday practicality, but someday—if government-sponsored space exploration takes off in a big way, as it would during a long-term Mars mission, or if commercial space tourism ever becomes commonplace—the functionality of such suits could save lives.

Because there’s so little air resistance in the atmosphere’s upper reaches, Baumgartner is expected to reach the speed of sound—around 690 miles per hour—rather than just the 120-mph terminal velocity of a skydiver at lower altitude. No one has ever bailed out in a spaceflight emergency, and it isn’t clear how best to do it safely. Baumgartner’s plunge will help fill in the knowledge gaps.

Baumgartner says he’s proud of the contributions he’ll be making to safer space travel, but he’s mainly interested in breaking records. The current skydiving altitude mark is 102,800 feet. It too was set by a man testing survival gear, in his case a parachute system. In 1960, in a project called Excelsior, U.S. Air Force captain Joe Kittinger stepped out of an open-top steel gondola carried by a helium balloon and skydived, in a partially pressurized suit, 19 miles to the ground. (Kittinger is an adviser on the Stratos mission.) In transcripts on file at the New Mexico Museum of Space History, in Alamogordo, Kittinger says he broke the sound barrier, but he wasn’t carrying the necessary measuring equipment to make the record official. Thus Baumgartner will probably also enter the record books as the first human to reach supersonic speed without being inside a jet or spacecraft.

For now, Baumgartner is slumped in a low chair, sipping water during a much-needed break. Today is the first time he’s worn the suit in wind-tunnel testing. He looks sweaty and undelighted. Pressure suits are heavy, claustrophobic, and restrictive. “There are some hot spots on the shoulder,” he says. He means places where the suit is rubbing.

The technicians exchange glances—there aren’t supposed to be any hot spots. “But it doesn’t matter,” Baumgartner says, adding that the jump is only six minutes long. He shrugs. “I’ll get used to it.”

BAUMGARTNER LEARNED about precision skydiving and aerobatics on a special-forces parachute team in the Austrian military from 1988 to 2002. A 1996 visit to Bridge Day, an annual BASE-jumping event in West Virginia, sparked a passion for this exceedingly dangerous sport. The BASE Fatality List on is, as of June 2010, at 147 deaths.

Tonight’s schedule includes only 15 minutes of “media time with Felix,” and later access was denied by Red Bull, so I can’t tell you as much as I’d like about the man inside the suit. Is Baumgartner the egotistical, publicity-thirsty “stunt-monkey” that critics on the blog would have you believe? (Among other things, his detractors say he falsely lays claim to the record for lowest BASE jump.) Or is he a talented, focused, career-savvy athlete who inspires jealousy and sour grapes? I saw no evidence of the former during my (admittedly limited) time with him, though Baumgartner’s Web presence is, it must be said, fairly devoid of humility. The Felix Baumgartner Wikipedia page lists his nickname as “God of the skies.”

From a purely visual standpoint, godlike isn’t too far off target. Baumgartner resembles a grittier, turbocharged Mark Wahlberg. To quote an industrial-products pamphlet I saw not long ago, he has very good bulk and edgeline toughness. He’s in the wind tunnel now, holding himself facedown in the classic free-fall position. He reaches around to his front to get a feel for the placement of the ripcord. (He can’t see it, because the space suit prevents him from bending or turning his neck.) Next he straightens his legs, assessing the suit’s flexibility. This adds surface area for the wind to push against, and he shoots up ten feet and then stops, hovering above a group of onlookers like a Macy’s balloon. He drops down again. Then up, then down, each time stopping an inch or two short of the webbing that forms the wind tunnel’s “floor.”

Red Bull Stratos technical project director Art Thompson cringes. Baumgartner’s chest pack contains an array of delicate medical instrumentation. “Felix!” Thompson barks into his mouthpiece. “Watch the chest pack!”

To get in position for the jump, Baumgartner will ascend in a custom-designed, pressurized capsule suspended below a huge—30 million cubic feet—helium balloon. (See “This Way Down,”) Once he jumps out, his biggest problem will be controlling his body’s position during free fall, due to the lack of air molecules in the upper atmosphere.

To get a sense of the problem, imagine holding your hand in the rushing air outside a car window. By angling your hand to present more or less surface to the wind, you can feel obvious shifts in direction and pressure. If the car were traveling 23 miles up, you’d feel none of that. Without air to apply counterforce, it’s harder for skydivers to stop a spin, and a poorly designed suit would make the situation worse. Baumgartner will need to free-fall for about 30 seconds before he gains enough speed to generate the wind force needed to control his position—or to benefit from the emergency stabilization chute he’ll carry.

The dangers of spinning were explained to me by retired Air Force colonel and master parachutist Dan Fulgham. Fulgham was Joe Kittinger’s backup before the record-setting Excelsior jump and is a veteran escape-system tester for the Air Force and NASA. During a 1963 test of the ejection system for a high-altitude jet called the X-20 Dyna-Soar, Fulgham went into a flat, turntable spin and experienced centrifugal forces so strong that he couldn’t hold his arms to his chest or control his legs.

“It was like I was encased in iron,” he said in a telephone interview. His chute opened automatically, but he still came close to dying. Sensors clocked him spinning at 163 revolutions per minute. “We ran some monkeys on the centrifuge at Wright-Pat, where the force was outward on the head at about 145 rpm,” he said, referring to the Wright-Patterson Aero Medical Laboratory, in Ohio. “The brain compressed enough into the top of the skull that it separated from the spinal cord. That should have happened to me.” He also could have died from “red-out,” wherein blood is spun into the brain with enough force to rupture blood vessels.

ONE THING BAUMGARTNER and the Stratos team will check out today is whether the space suit will allow him to get into proper “tracking” posture: angled downward with his arms extended from his sides in a V.

The mechanics are explained to me by Art Thompson, who is overseeing tonight’s tests. Thompson uses a pair of folded reading glasses to demonstrate. By shifting the center of rotation, the proper tracking position converts a tight, level, turntable spin into a larger, slower, more controllable three-dimensional spiral. If that doesn’t work during Baum­gartner’s jump, the forces of the spin will trigger the release of a stabilizing chute called a drogue. The drogue will pull his head upright, keep him from spinning into a red-out scenario, and, one hopes, save his life. (Unless it deploys prematurely, winds around his neck, and chokes him until he passes out, as Joe Kittinger’s did in an Excelsior dress-rehearsal jump from 76,400 feet. Kittinger’s main chute, triggered by an altimeter, opened automatically, saving his life.)

There is no way, down on earth, to simulate free fall in a near vacuum. The Air Force, in the 1950s and ’60s, used to try it by dropping anthropomorphic dummies out of high-altitude balloons. The results were worrisome: lots of high-speed spinning and tumbling. On a side note, civilians would sometimes be passing through the drop zone and head over to see what was going on. Because the project was operated in secrecy and the recovery teams behaved in a furtive, scurrying manner—and because the dummies had fused fingers and no ears or noses—the tests fueled long-standing rumors that the military was secretly recovering the bodies of aliens who had crashed in the scrublands outside Roswell, New Mexico.

On one occasion, the alien was Dan Fulgham himself. Fulgham and Kittinger crashed one Saturday morning in 1959 when their balloon came down in a field on the outskirts of Roswell. The 800-pound gondola had been released too early and begun to tumble, coming to a stop on Fulgham’s head. When he took off his helmet, his entire head swelled so severely that Kittinger described his face as “just a big blob.” Fulgham was taken to the hospital at Walker Air Force Base, in Roswell, which was staffed in part by civilians. I asked him if he recalls people pointing and staring.

“I don’t know,” he said, “because the only way I could see was to put my fingers up and pry my eyelids open.”

Art Thompson thinks the dummy results were misleading and that high-altitude spinning is unlikely to be a serious concern for Baumgartner. I brought up Fulgham’s near-lethal spin and Kittinger’s drogue-chute problem. Thompson pointed out that, back then, people didn’t skydive for sport the way they do now. “They weren’t used to the idea of controlling body position in flight,” he said. “There’s been so much advancement.”

But astronauts aren’t skydivers. And while Baumgartner will begin his descent at zero miles per hour, jumping from a balloon that’s drifting on air currents, a person ejecting from a spacecraft during reentry would be traveling in the neighborhood of 12,000 mph. It’s not a neighborhood you’d want to spend any time in.

JONATHAN CLARK, THE RED BULL Stratos Mission medical director, is well qualified for his post. Clark was a high-altitude-para­chute specialist working with the U.S. military’s special operations. He’s been a flight surgeon for NASA Space Shuttle crews, and he was involved in the investigation of the Columbia, which disintegrated over Texas during reentry in February 2003, killing all seven astronauts onboard. Clark’s team examined the autopsy reports to determine at what point the astronauts perished and how, and whether anything could have been done to save them.

Clark isn’t with us in Perris. I met him more than a year ago, up on Canada’s Devon Island, in the high Arctic, where NASA performs lunar and Martian expedition simulations at a site called the HMP Research Station. Clark showed me a PowerPoint about the technologies that air forces and space agencies and, lately, private companies have come up with to keep fliers and astronauts alive when things go wrong. It also covered the things that happen when those technologies fail—or, as Clark put it, “all the things that can kill ya.”

We sat at his desk in the medical tent. No one else was around. A wind turbine outside made a haunted, droning sound. At one point, without comment, Clark handed me an STS-107 mission patch, like the one Columbia‘s astronauts had worn. It seemed like a good time to ask about his work on the investigation.

I knew from reading a government document called the “Columbia Crew Survival Investigation Report” that the astronauts didn’t have their visors down when the crew compartment lost pressure. I wondered if they might have survived had their suits been pressurized and they’d been equipped with self-deploying parachutes.

The closest thing to a precedent was the crash of test pilot Bill Weaver. On January 25, 1966, Weaver survived when his SR-71 Blackbird broke up around him while traveling at Mach 3.2—more than three times the speed of sound. His pressure suit—and the fact that he was flying at 78,000 feet, where the air is about 2 percent as dense as the air at sea level—protected him from the friction heating and windblast that would, at lower altitudes, handily kill a person moving that fast. (Weaver briefly blacked out, but his chute deployed automatically at 15,000 feet.) Columbia was traveling at nearly Mach 17, but, given the negligible density of the atmosphere at 40 miles up, the windblast was about the equivalent of a 400-mph blast at sea level. It presented what Art Thompson describes as a manageable risk. “It’s survivable,” said Clark.

But the Columbia astronauts faced crueler threats than windblast and thermal burns. “We had some very unusual injury patterns that were not explainable by anything that we are accustomed to,” Clark said. (By “we” he meant flight surgeons: people accustomed to brains spun off their stems and limbs snapped by windblast.) “We know how people break apart,” Clark continued. “They break on joint lines.” Like chicken. Like anything with bones. “But this wasn’t like that. It was like they were severed, but it wasn’t from some structure cutting them up. And it couldn’t have been a blast injury, because you have to have an atmosphere to propagate a blast.”

As he talked, I was looking at the Columbia patch. The seven crew members’ last names were stitched on the perimeter: MCCOOL RAMON ANDERSON HUSBAND BROWN CLARK CHAWLA.

Clark. Something clicked in my head: When I first arrived on Devon Island, I’d heard that the spouse of one of the Columbia astronauts would be here. Jonathan Clark, I now realized, was the husband of astronaut Laurel Clark, who’d died. I didn’t know whether to say something, or what that something should be. The moment passed, and Clark kept talking.

The atmosphere at 40 miles up is too thin for blast waves but not for shock waves. The team concluded, mostly through a process of elimination, that it was shock waves that killed the Columbia astronauts. Clark explained that in high-speed breakups, like those above Mach 5—five times the speed of sound, or about 3,400 mph—an obscure phenomenon called shock-shock interaction is thought to come into play. When a reentering spacecraft breaks apart, hundreds of pieces—none with the carefully planned aerodynamics of the intact craft—are flying at hypersonic speeds, creating a chaotic web of shock waves. Clark likened them to the bow waves behind a water-skier’s boat. At the places where the shock waves intersect, the forces come together with savage, otherworldly intensity.

“It basically fragmented them,” Clark said. “But not everyone. It was very location-specific. We had things that were recovered completely intact.” One searcher who combed the Columbia‘s 400-mile debris path in Texas found a tonometer, a device that measures intraocular pressure. “It worked.”

PROTECTING PEOPLE in these conditions is a complicated challenge. Any spacecraft-escape system works with a limited range of altitude and speed. Ejection seats, for instance, work for the first eight to ten seconds of launch, before Q force—the interplay of air density and speed-generated wind force—builds to a lethal level. An ejection system needs to quickly blast the astronauts far enough away to keep them from smashing into the craft’s appendages or getting caught in the fireball of a catastrophic explosion.

To survive the extreme speed and heat of reentry is more problematic still. Roscosmos, the Russian space agency, has tested prototypes of an inflatable crew-escape pod called a ballute (an amalgam of balloon and parachute). Heat shielding on the broad forward face of the pod is designed to protect the terrified occupants, and the large surface area creates the drag needed to slow the pod to a speed at which a multistage parachute system could, if all goes well, lower it safely to earth. But such a system has never flown all the way from space to the ground, even in tests.

Alternatively, a parachute could lower an entire capsule or crew cabin to the ground. (NASA’s new Orion capsule may be used initially as an escape pod for the International Space Station.) The chute would be heavy and costly to launch—and in the case of the Space Shuttle, the process of separating the crew compartment from the rest of the craft pre­sents serious technical challenges.

While we’re at it, what about a more obvious customer base: airplane passengers? Is there a way to bail out safely from a jet that’s about to crash? Why, other than the weight and expense, don’t airlines outfit every seat with a portable oxygen supply and a seat-back parachute? For many reasons, but the main ones involve windblast and hypoxia.

At the halfway point of the Beaufort Wind Force Scale, air travels at 31 mph. “Umbrella use becomes difficult,” states the Beaufort, a tad overdramatically. The scale tops out at 73+, the starting point for hurricane-force winds that can reach 190. That’s about all the blow nature can muster. Where the Beaufort leaves off is where windblast studies begin. Windblast isn’t weather. The air isn’t rushing at you; you’re rushing at it—having bailed out or ejected from an imperiled craft.

At the speed of most private planes—135 to 180 mph—the effects of windblast are mainly cosmetic. The cheeks are pressed flat against the skull, bestowing a taut, facelifted appearance. I know this both from hideous photographs of me in the SkyVenture wind tunnel and from a 1949 Aviation Medicine paper on the effects of high-velocity windblast. In the latter, a man identified as J.L., handsome at zero mph, appears in a 275-mph windblast with his lips blown agape, gums in full view like an agitated, braying camel.

At 350 mph, the cartilage of the nose deforms and the skin of the face starts to flutter. “The waves begin at the corners of the mouth,” the Aviation Medicine paper explains, “and progress across the face at the rate of about 300 per second to the ear, where they break, causing the ear to wave.” At faster speeds, this Q force causes deformations that can, as Aviation Medicine gingerly phrases it, “exceed the strength of tissue.”

Cruising speed for a transcontinental jet is between 500 and 600 mph. At that speed, you cannot bail out. “Fatality,” to quote Dan Fulgham, “is pretty much indicated.” A windblast of 250 mph will blow an oxygen mask off your face. At 400 mph, windblast will remove a helmet—as it did to Bill Weaver’s SR-71 co-pilot. His visor was blown open and acted like a sail, snapping his head back against the neck ring of his suit and breaking his neck. At 500 mph, “ram air” blasts down your windpipe with enough force to rupture elements of your pulmonary system. A 1957 paper by the late Air Force colonel John Paul Stapp—a pioneering expert on survival during high-speed bailouts—mentions a case study from an aviation-industry interim report wherein an airman ejected at more than 600 mph. The windblast inflated his stomach like a pool toy. In this unusual instance, it helped the man survive when he hit water. “The estimated three liters of air in the stomach,” Stapp wrote, “substituted for flotation gear, which he was in no condition to inflate.”

AT SUPERSONIC SPEEDS, your body would face the kinds of Q forces that used to shake jets to pieces. Fulgham has seen autopsies of pilots who ejected at 600-plus. “Ejection seats back then had metal wings on each side of the head to keep it from flopping around,” he said. “When they did autopsies, they found the brains had just been emulsified because of the tremendous vibration of the head between those steel plates.”

That is why, whenever they can, fighter pilots stay with a crippled jet until they can slow it down, reducing the Q load. On this score, Red Bull has ample cause to be nervous about Felix Baumgartner. He could be vibrated to death inside his suit as he approaches or surpasses the speed of sound.

As this story went to press, Baumgartner had been doing test jumps from helicopters, and he’d already survived one close call. On March 21 of this year, unable to see the various handles on the front of his space suit because of his limited mobility, he cut away the wrong chute. He jettisoned his main chute instead of his drogue stabilizing chute. He did have a reserve chute, but he couldn’t tell, by feel, the difference between its deployment and cutaway handles. (The handles have since been modified.) Baumgartner began to tug at the cutaway handle, which, had it activated, would have left him without a chute. Dead.

Fortunately, the release was rigged so that it would not activate in those conditions. As risky as skydiving from extremely high altitude is, it’s still probably no riskier than Baumgartner’s other occupation—jumping from extremely low altitude. If something starts to go wrong during a space dive, you have six minutes to figure out how to remedy it. On a BASE jump, you barely have six seconds—and no reserve chute.

If you ask Baumgartner how he feels about the possibility of something going terribly wrong, he’ll give you the standard daredevil shrug: “I could die in my sleep.” Art Thompson isn’t worried about him. “He’s gonna be fine,” he told me in Perris. Let’s hope so.

Mary Roach’s new book, Packing for Mars: The Curious Science of Life in the Void—from which this article is adapted—will be published IN AUGUST by W. W. Norton & Company.

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