At 5 a.m. on April 5th, Mark Stucky drove to an airstrip in Mojave, California, and gazed at SpaceShipTwo, a sixty-foot-long craft that is owned by Virgin Galactic, a part of the Virgin Group. Painted white and bathed in floodlight, it resembled a sleek fighter plane, but its mission was to ferry thousands of tourists to and from space.

Stucky had piloted SpaceShipTwo on two dozen previous test flights, including three of the four times that it had fired its rocket booster, which was necessary to propel it into space. On October 31, 2014, he watched the fourth such flight from mission control; it crashed in the desert, killing his best friend. On this morning, Stucky would be piloting the fifth rocket-powered flight, on a new iteration of the spaceship. A successful test would restore the program’s lustre.

Stucky walked into Virgin Galactic’s large beige hangar. He is fifty-nine and has a loose-legged stroll, tousled salt-and-pepper hair, and sunken, suntanned cheeks. In other settings, he could pass for a retired beachcomber. He wears the smirk of someone who feels certain that he’s having more fun than you are.

Inside the hangar, he and his co-pilot, a Scotsman named Dave Mackay, spent thirty minutes in a flight simulator that approximated the current weather and wind conditions. Afterward, Stucky announced to colleagues that he and Mackay felt “pretty comfortable.” If all went according to plan, they would strap themselves into SpaceShipTwo—which was attached like a marsupial to the belly of a mother ship, WhiteKnightTwo—and take off from the runway, like an ordinary plane. At an altitude of forty-five thousand feet, WhiteKnightTwo would release SpaceShipTwo as if it were a bomb. Then, on Stucky’s command, Mackay would ignite SpaceShipTwo’s rocket. It would burn for thirty seconds, bringing them to a speed of more than eleven hundred miles an hour—nearly twice the speed of sound—and sending them to roughly ninety thousand feet, higher than Stucky had ever flown. (Passenger jets cruise at about thirty-five thousand feet.) If the flight landed successfully, and Virgin Galactic then completed a few more supersonic tests, the company could soon start offering spaceflights to the six hundred customers who have already paid a quarter of a million dollars for the thrill.

The Virgin conglomerate is owned by Richard Branson, the British billionaire, and Virgin Galactic is one of three prominent startups that are racing to build and test manned rockets. Its rivals are Blue Origin, which is owned by Jeff Bezos, the founder of Amazon; and SpaceX, which is owned by Elon Musk, the founder of Tesla. Musk has said that he hopes that all this rocket building will “inspire the public to get excited about space again.” Branson recently told CNN, “I hope that Virgin Galactic will be the first of the three entrepreneurs fighting to put people into space to get there.”

The companies have different visions for the journey. Virgin Galactic plans to take half a dozen passengers on a “suborbital” flight, cresting at more than fifty miles above the Earth. Blue Origin has a similar altitude goal for its first manned flights, but it is developing the kind of vertical-launch system that one associates with nasa rockets. SpaceX is perhaps the most ambitious: Musk wants to colonize Mars.

Mars is more than thirty-three million miles from Earth. By comparison, what is called “low Earth orbit” starts at a hundred miles above sea level; the International Space Station orbits a hundred and fifty miles above that; G.P.S. satellites, which operate in “medium” Earth orbit, are about thirteen thousand miles away. In February, SpaceX launched its biggest rocket yet: it is two hundred and thirty feet tall, and capable of transporting humans, and some seventy tons of payload, into orbit. In the CNN interview, Branson praised Musk and his team, saying that he’d love to try to “upstage that one,” but added that he would leave Mars to Musk.

Three months ago, Branson called me from Necker, his private island in the Caribbean, and said, “We see ours being the spaceship for Earth”—a vehicle whose purpose is not escapist but humanistic. He referred to a 1987 book, “The Overview Effect,” by Frank White, which quotes former astronauts reflecting on the profundity of staring at Earth from space. One of them describes the effect as a “feeling of unity.” Another says, “You don’t see the barriers of color and religion and politics that divide this world.” Branson told me, “I believe that, once people have gone to space, they come back with renewed enthusiasm to try and tackle what is happening on this planet.”

Branson is betting that a suborbital flight will be a transcendent experience, if not a very long one. Virgin Galactic passengers will spend about ninety minutes in the air; for most of that time, the craft will be coupled to WhiteKnightTwo as it climbs to forty-five thousand feet. After the rocket-boost portion of the flight, during which SpaceShipTwo will shoot upward at nearly ninety degrees, passengers, released from gravity’s pull, will be able to unbuckle their harnesses and float in the cabin for about four minutes, taking in stunning views of the Grand Canyon, the California coastline, and the Baja Peninsula. Like tour-bus drivers, the Virgin Galactic pilots will help passengers identify celestial bodies and terrestrial landmarks that can be seen out the window.

For now, this itinerary remains a fantasy. None of the startups has even attempted a manned spaceflight, and some experts view the idea of commercial space travel as irresponsibly risky. The explosions of the Space Shuttles Challenger, in 1986, and Columbia, in 2003, made clear that even formidable government agencies like nasa are susceptible to fatal mistakes. David Cowan, of Bessemer Venture Partners, which has invested in commercial satellite companies, told me, “If you want to build confidence in space, don’t try sending people there. Any failure will be a catastrophe.”

Shortly after 6 a.m., Stucky and Mackay stopped by the mission-control room, where three dozen engineers sat at consoles, reviewing the latest flight data. A supervisor directed them to confirm that they were ready to fly.

“Flutter: Go.”

“Aero: Go.”

“Stabs: Go.”

“Pneumo: Go.”

“Avionics: Go.”

“Prop: Go.”

“Thermal: Go.”

“Loads: Go.”

Stucky, speaking on behalf of himself and Mackay, solemnly addressed the people in the room: “We love you—no shit.”

The pilots retrieved their helmet bags from the locker room. They were driven to the east end of the runway, where WhiteKnightTwo and SpaceShipTwo had been towed. Lime-green fire engines, driven by men in hazmat suits, got into position. The sun rose over the buttes to the east, and a faint half-moon still hung over the Tehachapis, a mountain range to the west. On nearby hillsides, hundreds of wind turbines pinwheeled.

Stucky climbed through a side hatch into the left seat of the cockpit. He posted on Facebook, “Zero hour 9 am and I’m going to be high as a kite by then.” He put on his helmet, lowered its shaded visor, slipped on his gloves, and breathed through his oxygen mask, to insure that it was working.

Behind Stucky and Mackay was a seventeen-hundred-gallon tank of liquid nitrous oxide, and, farther back, a twenty-seven-hundred-pound rocket motor, which was packed with ignition squibs and one ton of solid fuel. After SpaceShipTwo was released, the squibs would be ignited as nitrous oxide was sprayed onto the solid fuel, generating a controlled explosion.

Rockets are categorized by propellant type: liquid, solid, hybrid. Each kind comes with advantages and risks. A solid-fuel motor is arguably the simplest, but it burns like a firecracker, making it less than ideal for manned spaceflight: if anything goes haywire, the rocket can’t be shut off and will probably blow up. With a liquid-fuel configuration, the pilot can use a throttle to limit the flow of fuel, but such engines are often extremely complex—relying on multiple valves and cryogenic storage tanks—thereby increasing the likelihood of something going wrong. 

Virtually from the start, Virgin Galactic had decided to focus on suborbital flights. Because such journeys would require much less fuel, energy, and infrastructure than orbital flights, tickets could be far cheaper. (A ticket for an orbital flight would likely cost tens of millions of dollars.) Moreover, whereas suborbital passengers would experience a minute of thrust, peaking at Mach 3, orbital passengers would experience more than eight minutes of thrust, peaking at Mach 25. After considering safety, cost, and the touristic goal of allowing passengers to view Earth while weightless, Virgin Galactic settled on a hybrid-fuel rocket that combined solid fuel with a liquid oxidizer. This configuration allows the pilot, at any time, to close a valve and halt the combustion process. And the solid fuel could be mixed in a way that would deliver an even, steady boost: a smooth ride. 

The rocket was the most fearsome motor Stucky had commanded in four decades of aviation. The previous night, and into the morning, propulsion technicians had been dialling up the pressure in the nitrous tank. By this point, Stucky said, “the spaceship goes from being something you could safely park next to at a gas station to becoming a bomb.” Mackay further increased the pressure by flipping a switch that released helium from a smaller tank in the nose of the ship into the nitrous tank. The sound reminded Stucky of an old furnace hissing and clattering to life.

Such tactile sensations were part of SpaceShipTwo’s appeal. Despite the futurism of its mission, the vehicle was a relatively simple aircraft. No autopilot. No automation. The other space companies would control the journey to space with computers: everyone on board was more or less along for the ride. Once a Virgin Galactic ship was airborne, the fate of the ship and its crew was in the pilot’s hands.

As the lead test pilot, Stucky was expected to navigate unexplored aerodynamic realms, so that the engineers could define the spaceship’s capabilities and limits. Each test flight offered some new adventure. But “expanding the envelope,” as test pilots describe their work, was not adventurism for its own sake; it was a process that drew just as much on the discipline and the rigor of the scientist as on the artful improvisation of the daredevil. Fly, test, notate, adjust; fly, test, notate, adjust. This was the only way to guarantee that the spaceship would be ready for commercial service.

In some ways, SpaceShipTwo was a throwback, modelled on the experimental X planes that the Air Force and nasa had flown in the mid-twentieth century. In 1947, an X-1 piloted by the Air Force captain Chuck Yeager became the first vehicle to break the sound barrier. In the sixties, test pilots flew the X-15 above Mach 6, reaching three hundred and fifty thousand feet. SpaceShipTwo’s design engineers had used some of that flight data. “That’s the basis of our models,” Mike Moses, the president of Virgin Galactic, told me. “But the X-15 had a whole different wing profile, vehicle loft, and control scheme. We can tweak that data for our vehicle, but, really, we have to plow that ground ourselves.”

Comparing SpaceShipTwo with Blue Origin’s New Shepard suborbital rocket was equally inadequate. Moses explained, “A vertical-launch rocket handles those regimes a whole lot differently than an airplane with wings.” For a pilot like Stucky, the Blue Origin scheme held little appeal. “It’s automated,” he said. “They’ve got some astronauts, but I don’t know what the hell they’re going to do besides act like they’re doing something. It’s ‘Three, two, one—blastoff.’ ”

His hauteur echoed that of the X-plane pilots. Men like Yeager disparaged the Mercury astronauts for putting themselves in a capsule without any flight controls and then claiming they had flown it. In “The Right Stuff,” Tom Wolfe writes that test pilots referred to astronauts as “Spam in a can,” and notes, “Astronaut meant ‘star voyager,’ but in fact the poor devil would be a guinea pig.”

At 8 a.m., WhiteKnightTwo, which has a hundred-and-forty-foot wingspan, powered up its four jet engines and charged up the runway. The mother ship has two fuselages, side by side, and SpaceShipTwo was nestled between them. The pilot of WhiteKnightTwo, Mike Masucci, climbed above forty thousand feet, flying over Death Valley, then banked west, toward Sequoia National Park, and, finally, south, back toward Mojave. Stucky looked out the window of SpaceShipTwo and wondered if his wife, his son, his daughter, and his daughter’s husband—all of whom were watching him from the runway—could see him through the spotty clouds.

He extended his right hand, and Mackay grabbed it: their fates were intertwined. A radio operator gave them clearance to start their “L-4” checks: four minutes until rocket launch.

Mackay: “Roll boost?”

Stucky: “On.”

Mackay: “Speed brake?”

Stucky: “Enabled.”

Mackay: “Dampers?”

Stucky: “On.”

They were ready. Thirty seconds before rocket launch, Mackay flipped the switch that controlled the release mechanism, and said, “SpaceShip is armed, with a yellow light.” From WhiteKnightTwo’s cockpit, Masucci counted down: “Three, two, one. Release, release, release.”

Mark Stucky grew up in Salina, Kansas, where his father, Paul, taught physics at a local college. The family lived in a one-story brick home. On February 20, 1962, when Stucky was three, he watched a rocket launch on TV. As John Glenn rode an Atlas rocket into orbit, Walter Cronkite, the CBS anchor, cheered, “Go, baby!” Glenn, then a forty-year-old marine, circled the Earth three times. “That view is tremendous,” he reported, while looking out the window. Five hours after liftoff, Glenn, in a six-by-seven-foot capsule, splashed down in the Atlantic Ocean.

Paul Stucky deeply respected the space program, and when Mark showed an interest in astronomy he fostered it, taking him and his sisters to the observatory at Kansas Wesleyan University. But Paul was also a Mennonite; as a conscientious objector, he spent the Second World War at a Civilian Public Service camp in Puerto Rico. When Stucky told his dad that he hoped to become an astronaut, Paul replied that doing so was impossible. Astronauts were selected from the military, and no son of his would ever serve.

Stucky didn’t bring it up again for years. But in grade school he came across an old article in National Geographic, “I Fly the X-15, Half Plane, Half Missile,” co-written by Joseph Walker, an Air Force pilot. Walker described an X-15 flight: “Acceleration from that inferno in the tail pipe pinned me back in my seat.” Stucky told me, “I was enthralled.”

At thirteen, he was captivated by another National Geographic story, about Californians who had taken up the new sport of hang gliding. The author described taking off from a hill above Newport Beach: “What can I tell you about this first step that encounters nothing solid? There’s nothing to it. This upward stride causes the jaw to drop and the mind to cease its disciplined churning.” Stucky persuaded his dad to split the cost of a glider. He made his first flight on May 15, 1974, near Wilson Lake, Kansas.

Stucky enrolled at Kansas State University, majoring in physical science, but often skipped lectures and went to the library to study topographical maps of flint hills in the area. He became skilled enough at gliding that he performed, uninvited, at the halftime show of a football game, mounting a two-stroke engine on his kite and flying around the stadium. In 1980, he was interviewed by K-Stater, the alumni magazine, and confided his hope of becoming an astronaut. “I hate to tell people that, because it seems like such a kiddie dream,” he said.

After graduation, he defied his father and enlisted in the Marines. Paul told him that he’d spend his time peeling potatoes and would never become a pilot. But Stucky was accepted into flight school, and in 1982 he joined a training squadron for F-4 Phantom pilots in Yuma, Arizona. (At the time, my father, a former Marine fighter pilot, was an instructor in the squadron.) A senior officer advised him to keep his desire to become an astronaut to himself, because the Marines resented it when top fighter pilots were yanked out of combat squadrons. Nevertheless, Stucky stood out. He was a remarkable aviator, in part because his eyesight was so good. (“It came to that, time after time, who could see the farthest,” James Salter wrote in “The Hunters,” his novel about Air Force dogfighters in the Korean War.) Stucky also was a showboater. In 1985, on a patrol mission over the Sea of Japan, he spotted a Soviet bomber in the distance, caught up to it, flipped upside down, got close enough that only a few dozen feet separated the cockpits, and snapped a photograph.

In 1989, Stucky applied to nasa to become an astronaut. He advanced to the final round, but didn’t make the cut. Two years later, he had the same frustrating result. Looking back, he compared the process to competing in the Miss America pageant: “You can be one of fifty very talented and beautiful women, but you can’t plan on winning. There’s an element of luck involved.”

nasa clearly liked what it saw, however, and offered him a job, in Houston, as a test pilot. He accepted, and left the Marines. Three years later, nasa sent him to the Dryden Flight Research Center, its flight-test facility at Edwards Air Force Base, in the California desert, where Chuck Yeager spent most of his career.

Stucky’s superiors were impressed by his piloting skills; an evaluation said that he had “no apparent weak points.” In 1997, he got a chance to fly the world’s fastest spy jet, the SR-71 Blackbird. He put on a yellow pressure suit, climbed to eighty thousand feet, and crept past Mach 3. He was merely a quarter of the way to space, and yet, as he later wrote in the magazine Flyer, he could see “the infinite azure of the Pacific Ocean” and the curvature of the Earth.

At Dryden, he began taking on engineering projects. In 1998, nasa was contemplating a manned hypersonic-research jet, and Stucky was asked to consult with outside experts. He invited Burt Rutan, an eccentric, muttonchopped engineer who lived in Mojave, out for lunch.

Rutan had founded a company, Scaled Composites, that was producing a cutting-edge prototype every year. “I like to do far-out things with airplanes,” Rutan told CNN. One of his planes, Voyager, looked like a jumble of toothpicks, but it was the first plane to fly around the world without stopping or refuelling; Proteus, which set several altitude records, resembled a prehistoric bird. Today, five of Rutan’s planes are displayed at the National Air and Space Museum.

For Rutan, the desert isolation of Mojave, which is twenty miles northwest of Edwards, made it an ideal place for flight testing. Overhead was a block of military airspace where commercial traffic was forbidden. Sonic booms from Edwards often shook buildings. “This is the Silicon Valley for the new industry,” Jeff Greason, a veteran of Mojave’s aerospace industry, told the Los Angeles Times in 2007. “Nobody complains about making noise, or sending plumes into the sky.”

Stucky wasn’t expecting more than a brainstorming session with Rutan, but Rutan showed up with sketches for a scramjet—a plane that achieves combustion by funnelling supersonic air directly into the engine. Stucky told his bosses at Edwards about the drawings, but they showed little interest. Aviation priorities were changing: manned missions were out of fashion, drones were the rage, and national-security budgets were tight.

Stucky resigned. “It is disappointing to me that the world’s premier flight-test organization could consider going for extended periods without any . . . piloted research projects,” he wrote, in a departing note to nasa. “Dryden established its reputation by making the impossible possible but increasingly we seem content to make the possible impossible.”

He began flying for United Airlines, and sold mortgages for a few years, before going on active duty with the Air Force, in 2003. A year later, he deployed to Iraq. In an e-mail to friends and family, he recounted a harrowing, low-altitude helicopter ride across Baghdad: “I don’t care how much someone might have liked you, if you keep flying over their heads at 100 feet they are gonna eventually get annoyed.”

One night, he stayed up late to watch TV. He’d learned that Rutan was preparing to launch a manned, homemade rocket ship into space, and didn’t want to miss the event.

In 1996, an entrepreneur named Peter Diamandis announced that he would award ten million dollars to the first private citizen who sent a manned vehicle into space twice within two weeks. He called his contest the X Prize, and modelled it on a twenty-five-thousand-dollar award offered in 1919 to the first aviator to fly non-stop between New York and Paris. Four pilots died trying, and two others disappeared, before Charles Lindbergh, in May, 1927, crossed the Atlantic in the Spirit of St. Louis.

Working behind a partition inside a Scaled Composites hangar in Mojave, Rutan and his team built a potbellied, high-winged, twenty-eight-foot-long plane, with three seats, simple controls, and a rocket in the rear. “If space is going to be cheap, it has to be stick-and-rudder,” Rutan said at the time. He called the vehicle SpaceShipOne. Inspired by nasa’s use of airborne platforms to launch the X-1 and the X-15, Rutan also developed a mother ship, which he named White Knight.

On June 21, 2004, tens of thousands of space-travel enthusiasts gathered in Mojave to witness the flight. Some visitors likened the experience to watching the Wright brothers at Kitty Hawk.

A few minutes before 7 a.m., White Knight took off, with SpaceShipOne attached underneath. At forty-seven thousand feet, Mike Melvill, the SpaceShipOne pilot, commanded release; then a fiery plume shot out of the rear nozzle, as Melvill pulled back on the stick, aiming SpaceShipOne straight up. He was moving at Mach 3, and after he shut the motor down, as planned, the craft coasted past what is widely recognized as the boundary of space: sixty-two miles, or three hundred and thirty thousand feet, above sea level.

Stucky watched a broadcast of the launch from his office, in one of Saddam Hussein’s former palaces. Rutan’s success filled him with elation, envy, and hope. After his unsuccessful bids at becoming a nasa astronaut, he’d resigned himself to never reaching space. Now he wondered if there might be another way.

In the fall of 2004, SpaceShipOne completed two more spaceflights, earning Rutan the X Prize. President George W. Bush called to congratulate him. Buzz Aldrin, the second man on the moon, and William Shatner, of “Star Trek,” both witnessed the winning flight. Also in attendance was Richard Branson, the flaxen-haired British entrepreneur. Branson was invested in Rutan’s success, both financially and emotionally. At the age of thirty, Branson had produced a documentary to commemorate the Apollo 11 moon landing—a psychedelic montage of telescope images, ambient soundscapes, and John F. Kennedy’s “moon shot” speech. Eight years later, in 1988, Branson, who had recently launched a Virgin airline, appeared on the BBC program “Going Live!” A viewer called in and asked him if he’d contemplated extraterrestrial ventures. “I’d love to go into space,” Branson said. “If you’re building a spacecraft, I’d love to come with you.”

When Branson learned about SpaceShipOne, he made a deal with Paul Allen, the co-founder of Microsoft, who had been discreetly funding Rutan: Branson, they agreed, would pitch in a million dollars, and would secure the right to adapt Rutan’s design for space tourism. A week before Rutan won the X Prize, Branson announced the formation of Virgin Galactic. His timing was opportune. nasa’s funding was being cut, and the Space Shuttle program was sputtering out. Branson promised a ride on a spaceship to anyone with a quarter of a million dollars to spare. (Leonardo DiCaprio was among the six hundred people who signed up.)

Branson had no experience building rockets, so he contracted Rutan to do the work. The program ran into difficulties, some of them caused by Branson’s efforts to attract publicity. He’d announced that spaceflights could start as early as 2007, a wildly unrealistic projection, considering that Rutan and his team still had to design, build, test, and license two new vehicles, SpaceShipTwo and WhiteKnightTwo. Although these were being modelled on SpaceShipOne and White Knight, they had to be much bigger. SpaceShipOne could accommodate three people on board, and had a rocket that generated about twenty thousand pounds of thrust; for SpaceShipTwo, designed to carry two pilots and six passengers, the engineers calculated that they needed at least seventy thousand pounds of thrust. Propulsion is difficult to scale, and designing a viable rocket motor was giving Rutan’s team fits.

On July 26, 2007, a team of Scaled Composites engineers and technicians gathered at a site north of the Mojave airport to test their new hybrid-fuel rocket motor. A 1991 article in Aerospace America had praised hybrid-fuel rockets as “safer, more reliable, [and] more cost-effective” than rival designs. But they were not risk-free.

The engineers of the new rocket wanted to check the flow rates of nitrous oxide. At 2:30 p.m., the tank holding the nitrous oxide became overpressurized and exploded. Shrapnel sprayed in every direction. Three people died, and three others were severely injured. In a blog post, New Scientist said that the accident “raised serious questions about safety practices at Scaled.” Jim Tighe, the company’s lead aerodynamicist, told me, “It was a real blow to our confidence.” Rutan took a medical leave, citing heart difficulties.

Stucky hang gliding in his home town of Salina, Kansas, in 1974. Photograph courtesy Paul Stucky via Mark Stucky

At the time, Mark Stucky was living in Las Vegas. After four deployments to Iraq, he’d received the Air Force’s Bobby Bond Memorial Aviator Award, which cited his “incredible resourcefulness and real courage” in training the Iraqi Air Force. In 2007, he moved to Nevada to work on a highly classified program; he wrote his own obituary, in case he was in a fatal accident. His schedule was erratic, and the secrecy strained his family life. His son, Dillon, who is now twenty-nine, told me, “He would be gone for a week, and couldn’t talk about where he’d been or what he was doing.”

Stucky had bought a paraglider that he could stuff in a backpack, and he leaped off cliffsides and soared over the desert. In a 2006 book that he co-authored, “Paragliding: A Pilot’s Training Manual,” he wrote that he loved the “elegant simplicity of the sport.” His wife, Joan, accused him of having a “sickness” for flight. Stucky believed that she intended this to sound diagnostic. Several of his family members had suffered from mental illness. Stucky recalled his father, in old age, saying, “Tell your friends in the C.I.A. that those window washers aren’t fooling anybody.” His mother, Lidia, became schizophrenic. While he was working for United, she once called in a bomb threat at LAX. But Stucky had passed one psychological examination after another in the Air Force. He told Joan that she was trying to shame him about his passion.

In late 2007, he asked the president of Burt Rutan’s company, an engineer and a test pilot named Doug Shane, about opportunities at Scaled Composites. The next March, Shane invited him to Mojave for a tour of the hangar and to fly the SpaceShipTwo simulator. Stucky performed well, and afterward he wrote to Shane, “You asked me about what I have to offer aside from flying. I have a reputation for getting things done successfully and one of my strong points is an ability to ferret out the real safety issues from the imagined.” Scaled Composites, he noted, had an “unequaled ability at figuring out what the real design and flight test issues are and then successfully addressing them,” adding, “I would meld well with your existing philosophy.”

A month later, Stucky and another member of the Desert Skywalkers, the local paragliding club, met near a ridge overlooking a dry lake bed south of Las Vegas. Before jumping, Stucky had noticed a few dust devils in the distance. “I knew there was some potentially evil air out there,” he said. Not long into the flight, a funnel cloud blew out his canopy. Stucky was three hundred feet above the ground, spinning out of control. As he fell, he tried to reopen the canopy. “I was purposely not looking at the ground, because I thought it would just slow me down,” he told me. “It’s kind of like having a revolver and having somebody rushing you and you’ve got to load the revolver with one bullet. If you sit there and look at him and try to hurry, you’re probably not going to do as good of a job as if you’re just methodically looking at the bullet, putting it into the revolver, aiming, and then pulling the trigger.” Sixty feet above the ground, he pumped the canopy back open, but it was too late to arrest his fall and he slammed into the ground. The impact collapsed both his lungs, shattered a vertebra, and compressed three others. He crawled to the nearest road and flagged a motorist, who called for help.

Stucky spent the next three months in an upper-body brace, recuperating in the guest bedroom of his house. The injury further stressed his marriage. Joan insisted that he stop paragliding. “My wife had no appreciation for my love for flight,” Stucky later wrote, in the magazine Hang Gliding & Paragliding. He filed for divorce. (Joan told me that Stucky’s characterization of her was “absolutely false,” adding, “I supported him in everything he did for twenty-nine years.”)

Stucky took off for California and moved in with a woman, Cheryl Agin. She had worked in the public-affairs department at Dryden, where, she recalled to me, “the pilots were the rock stars, and he was definitely the best-looking of them all.” She went on, “He would do the coolest flybys”—low-altitude, high-speed passes—“and he would get in trouble for them, but of course we all loved it.” When Agin became involved with Stucky, she knew what she was getting into: her father had been a civilian engineer on the X-15 project. Stucky told me, “She understood that flying is a part of my core.”

After his three children learned about Agin, they blocked his calls and ignored his e-mails. He wrote a song for his elder daughter, Sascha, and paid a professional guitarist to perform it; he sent her a recording, but didn’t hear back. Dillon, who had gone to the Air Force Academy to become a pilot, transferred to U.C.L.A. He competed in track and field, and on his U.C.L.A. profile page he listed, under “personal,” only his mom and two sisters. Stucky and Agin sometimes travelled to Dillon’s track meets, but, wary of being rejected, they lurked in the bleachers.

In April, 2009, Stucky accepted a test-pilot position with Scaled Composites. His portfolio included the SpaceShipTwo program. It should have been everything he wanted. But his estrangement from his children tempered his excitement. The military had trained him to compartmentalize distractions, but, commuting forty minutes every day on an empty desert highway, he had plenty of time to contemplate how badly he missed his kids.

That August, he wrote to Dillon, “The only way I can see that I would be so shutout is that you have been convinced that I have wronged your mother and/or am a scumbag. Neither is the case. . . . My previous job required me to sometimes be less than candid about what I did and where I was. That is over. If you will allow it, I would be happy to answer any personal (not prior job-related) questions with 100% truth and then let you be the judge and jury of my fate as a father.” He received no reply.

The engineers at Scaled Composites worked out a detailed flight-test program for SpaceShipTwo and WhiteKnightTwo. To prove the vehicles’ airworthiness to their client, Virgin Galactic, they needed to successfully complete a couple of “captive carry” flights (SpaceShipTwo remaining mated to WhiteKnightTwo), a dozen or so “glide” flights (SpaceShipTwo, upon release from WhiteKnightTwo, gliding down for a landing), and several “powered” flights (SpaceShipTwo, upon release from WhiteKnightTwo, igniting its rocket).

Stucky and another Scaled Composites test pilot, Peter Siebold, took turns in the pilot’s seat. Siebold, who was a decade younger than Stucky, was a prodigious engineer who’d been hired by Scaled Composites before he’d even graduated from college. Stucky found him intimidatingly smart; in a 2009 e-mail, he wrote, “I can point out how to make things better, but, unlike Pete, I can’t sit down and write the code to implement them.” But, the more Stucky got to know Siebold, the more he found him to be worrisomely cocky. For aviators, confidence is an asset but arrogance is a liability. As Chuck Yeager, who started his flying career as an ace in the Second World War, wrote in his memoir, “Arrogance got more pilots in trouble than faulty equipment.”

On October 10, 2010, Siebold flew the first successful glide flight. Rutan sent out a celebratory e-mail, spurring his employees to “reach our goal” of engineering “a spaceship capable to provide the space experience to thousands of adventurers.” They were hoping to install a rocket motor soon, but their propulsion problems had yet to be solved, so Stucky and Siebold continued doing glide flights.

Stucky flew the sixteenth glide flight on September 29, 2011. The word “glide” makes these flights sound deceptively tame. Some of them were extremely challenging, part of the battle testing that SpaceShipTwo had to endure before initiating commercial service. The sixteenth glide flight was designed to assess the craft’s propensity for “flutter”—oscillations across the wings and the tail which could lead, in extreme cases, to the vehicle’s breaking apart. The engineers wanted Stucky to enter a sharp dive, targeting a maximum speed just below Mach 1. Upon release, Stucky held the stick all the way forward, as planned. But the engineers hadn’t fully accounted for such a steep angle of attack, and the tail lost lift; the spaceship suddenly flipped upside down and began spinning to the left.

Stucky counted each rotation as the plunging craft spun past the sun: One, two . . .

In other vehicles, he had often practiced entering, and recovering from, inverted spins like this. These were unpleasant and dangerous maneuvers. In 1953, Yeager was flying an X-1 when he inadvertently entered an inverted spin at eighty thousand feet. As he later told NPR, for nearly a minute he was “fighting to try to recover the airplane and stay conscious from the high rotational rates.” At twenty-five thousand feet, he regained control. Thirty-two years later, the stunt pilot who filmed Yeager’s scenes in “The Right Stuff” was doing stunts for “Top Gun” when he entered an inverted spin; he crashed and died.

Stucky knew that he had to move quickly to slow the spin. He was falling five hundred feet a second. He deployed the speed brakes and stepped on the opposite rudder pedal, but the spaceship continued to tumble: Three, four . . .

He was out of ideas, preparing to open the hatch and parachute out, when something occurred to him. A decade earlier, when Rutan was designing SpaceShipOne, he’d been deeply concerned about the vehicle reëntering the Earth’s atmosphere askew and breaking apart. In 1967, a friend of his named Mike Adams had been flying the X-15 at Mach 5 when he lost control, and reëntered the atmosphere spinning sideways. This chaotic descent generated fifteen g’s, or fifteen times the force of gravity, and the plane was pulverized in midair. As a fix, Rutan made his spaceship’s tail booms—flat panels that normally are parallel with the base of the fuselage—movable. When they were raised perpendicular to the fuselage, the craft slowed down and started descending like a shuttlecock. Rutan called his innovation the “feather.” In the documentary “Black Sky,” Brian Binnie, a former Scaled Composites test pilot, calls the feather “the angel’s wings on this vehicle.”

Stucky slid the feather handle to the “unlock” position, and raised the feather. The vehicle immediately stopped tumbling forward. Stucky regained control and glided to Earth. The angel’s wings had saved him, his co-pilot, and a flight-test engineer sitting in the back from almost certain death.

One evening, Stucky and Agin, who married in 2011, had me over to their house for a drink. They live in a hillside subdivision overlooking Palmdale, a city south of Mojave. We had been sitting around a fire pit in their back yard when Stucky invited me to see the cockpit video from glide flight sixteen. I followed him to his office computer. He pulled up the video, and the footage was upsetting: Stucky straining to avoid passing out; hazard alerts beeping; red lights flashing on the cockpit console; the horizon whipping past. Agin, a stern, fit woman with a pixieish haircut, watched over Stucky’s shoulder, swallowing tears.

He paused the video. “Is this emotional for you?” he asked, sounding sharper than he intended.

“It’s O.K.,” Agin replied.

They didn’t discuss the dangers of his job much. Stucky told me that Agin had an “overinflated opinion” of him, and that he didn’t want to frighten her. She told me, separately, “He’s gifted”; one of her friends, a photographer at Dryden, had flown with Stucky and told her that Stucky was the best pilot she’d ever gone up with. Agin tried not to worry about him. Years ago, when he came home with documents for her to sign, detailing medical-emergency protocols in the event of a crash, she broke down. “I just had never even thought about the possibility that that would happen,” she said.

Stucky said, “We’re test pilots of spaceships. As a Marine Corps colonel once told me, ‘If you want to be safe, go be a shoe salesman at Sears.’ ”

Scaled Composites began rocket-powered flights on April 28, 2013. Peter Siebold was supposed to pilot the first one, but he broke his heel in a paragliding accident, and Stucky took his place. The night before the flight, he and Agin drove to Mojave and checked into a hotel by the airport. Stucky woke up at 3 a.m., ate yogurt and string cheese, and reported to the hangar for a briefing.

He’d spent weeks running through every anticipated action and utterance during the flight, wondering what might go wrong. “I’m always thinking about emergencies and how I would handle them,” Stucky told me. He memorized flight plans until they were like songs stuck in his head.

His co-pilot was Mike Alsbury, a thirty-eight-year-old engineer at Scaled Composites. Alsbury, who regarded Stucky as a mentor, was studious and humble, rare qualities in a community of hot shots. Stucky once described him as “the consummate professional,” praising his “over-all flight-test knowledge.”

Before a test, the engineers draw up a “flight card,” describing the purpose, the limitations, and the priorities of the journey. That day’s card directed Stucky and Alsbury to burn the rocket for sixteen seconds. Shortly after dawn, they boarded SpaceShipTwo, which was affixed to WhiteKnightTwo, and took off. When they reached their target altitude—forty-seven thousand feet—the release latch was activated and the spaceship fell away. “Fire,” Stucky said. Alsbury ignited the rocket.

Within seconds, they were hurtling forward at more than seven hundred miles an hour. Stucky’s heart rate jumped, but he maintained a clinical manner. “If you savor the moment, you can miss a test point,” he told me.

Approaching Mach 1, Stucky felt the ship twitching. He strained to keep the nose level. They had entered the “transonic zone,” a band of airspeed between Mach 0.8 and Mach 1.2. On Earth, sound waves generally travel between six hundred and fifty and seven hundred and fifty miles per hour, depending on the altitude, the air temperature, and other factors. Before Yeager broke the sound barrier, some people doubted whether it could be done, and suspected that undefined aerodynamic forces would destroy an object moving that fast. Strange things happened to aircraft entering the transonic zone. Instrument gauges went wacky. Flight controls stopped working. Yeager, reflecting on flying transonic for the first time, recalled, “It felt like I was driving on bad shock absorbers over uneven paving stones.” In 1956, a Navy test pilot passing through the transonic zone fired his cannons, caught up with his own bullets, and shot himself down.

During subsonic flight, air molecules move to one side or another of an oncoming wing. But, when an aircraft approaches supersonic speeds, the molecules can’t move fast enough, and stack up, forming shock waves. These waves cause transonic instability. “The flight controls feel like they’re in hardening concrete,” Stucky said. “We know a lot about supersonic, and a lot about subsonic, but transonic? It’s the unknown”—the Bermuda Triangle of airspeed.

Every supersonic airplane experiences transonic instability of some kind, but engineers can program modulations into the flight computers of most modern jets in order to mute some of the bobbling. SpaceShipTwo was a more austere machine, and in its first supersonic flight Stucky felt the bobble more intensely than he’d expected. But he and Alsbury rumbled through the unstable air, smoothed out the ride, peaked at Mach 1.31, and then, as planned, shut off the rocket motor. Their flight trajectory was a parabolic arc. At the top of it, Stucky fetched a sock monkey from a side console and lobbed it into the air. It floated, illustrating zero gravity for crew members back at mission control who were monitoring the cockpit.

The flight took just thirteen minutes. Branson, who embraces risk almost as avidly as Stucky does, was waiting on the runway. How was it? Branson asked him, slapping him a high ten. Stucky replied that he’d been tempted to let the rocket burn and head straight into space. “That’s my kind of guy!” Branson said.

A view of Earth from SpaceShipOne, during a 2004 flight. Photograph courtesy Virgin Galactic

Scaled Composites didn’t attempt another rocket flight for five months. The engineers were still contending with propulsion problems, though they didn’t acknowledge it publicly. After the fatal nitrous-oxide explosion, they outsourced rocket development to the Sierra Nevada Corporation, which promised to deliver a motor capable of a stable minute-long burn. But, in initial ground tests, prototypes were vibrating excessively on the stand long before sixty seconds. This caused tremendous concern at Virgin Galactic. Mike Moses, the president, couldn’t imagine moving forward with such a motor, even if Sierra Nevada could tweak its design so that the rocket burned for a full minute. Humans didn’t respond well, he noted, to excessive “eyeball-vibration frequency.”

Quietly, Virgin Galactic and Scaled Composites began pursuing alternative rocket programs. Jarret Morton, a thirty-one-year-old rocket scientist, was placed in charge of Virgin Galactic’s effort. In November, 2013, he wrote an e-mail to management asking to fire Sierra Nevada “as soon as possible.” 

At one point, Steve Isakowitz, then Virgin Galactic’s chief technology officer, met with Elon Musk and asked him about buying Merlin rockets from SpaceX. The Merlin is a liquid-fuel rocket, but Scaled Composites had done a feasibility study and concluded that its craft could use such engines. Musk offered to sell a Merlin. But the price was high, and the Merlin was so large that expensive modifications would have to be made to SpaceShipTwo in order to accommodate it. Virgin Galactic decided instead to design its own rocket, under Morton’s direction. 

In the meantime, Stucky and the other pilots would continue flight testing using Sierra Nevada’s motor. It was qualified to run for only thirty seconds, but short flights were better than no flights. Even with twenty-second burns, the pilots could continue expanding SpaceShipTwo’s envelope.

The team focussed on addressing some of its concerns about maneuvering in the transonic zone, and Stucky worked on improving communication between the pilot and the co-pilot. On future flights, he wanted the co-pilot to announce when the spaceship had reached Mach 0.8. That way, the pilot could anticipate transonic instability. The engineers installed fins on the top of SpaceShipTwo’s wings to help dampen the pitch bobble.

With Siebold still recuperating from his injury, Stucky flew the next two rocket-powered flights, in September, 2013, and January, 2014. The modifications paid off: he pushed through the transonic zone with ease. After the second flight, he was honored by the Society of Experimental Test Pilots with its annual Iven C. Kincheloe Award, named for an Air Force pilot who, in 1956, became the first person to fly above a hundred thousand feet. The award was gratifying, but Stucky was even more pleased when his daughter Sascha came to Mojave to watch him fly. Her boyfriend, Jonathan, had recently decided to propose, and had visited Stucky to secure his blessing. Jonathan then urged Sascha to give her father a second chance. She agreed, and asked him to walk her down the aisle.

The next rocket-powered flight was scheduled for October 31, 2014. Siebold was feeling healthy again, and he assumed the pilot’s seat. Stucky would remain on the ground this time. Siebold chose Mike Alsbury to be his co-pilot.

Stucky was happy for Alsbury. They had become close while working together on a classified project for Scaled Composites. For more than a year, they had kept a gruelling travel schedule, spending most weekdays away. It had been tough on Alsbury, who was married and had two kids, but he was pleased to have forged such a strong bond with Stucky. They shared meals, and Stucky enjoyed hearing Alsbury talk about his daughter and son. Once, back in Palmdale, Stucky accepted an invitation to throw the first pitch for Aerospace Aviation Night at the local minor-league baseball stadium. He worried about embarrassing himself, and Alsbury offered to meet him at the park one afternoon before the game, to practice. Alsbury’s daughter, Ainsley, watched from the grass as Stucky pitched to her dad.

By the time the October launch date was announced, SpaceShipTwo had completed eighteen captive-carry flights, thirty glide flights, and three rocket-powered flights. For the new flight test, Scaled Composites had installed a rocket motor of its own design, and planned to let it burn for thirty-eight seconds, with the goal of propelling SpaceShipTwo above a hundred and thirty thousand feet. After two or three more flights like that, they might be ready to take their first passengers—Branson and his two kids—into space. Sam Branson, the billionaire’s son, told NBC, “I think any rational person would be slightly nervous.”

On the thirtieth, Alsbury left work early and went with his wife, Michelle Saling, to Ainsley’s dance practice, and also attended Family Night at their son’s school. Liam, a second grader, wanted to become a pilot. After saying good night to his kids, Alsbury fell asleep at nine.

Stucky, who on that day would be assisting the test conductor in mission control, reached the airport at 4 a.m. At the hangar, things struck him as a bit disorderly: a sensor system in SpaceShipTwo had fuzzed out and was being replaced; the nitrous truck had come late, so the liquid inside it was too cold, and thermal blankets were now draped over the tank. Siebold, meanwhile, was pacing the tarmac in the dark.

By 8 a.m., the sensor system had been fixed and the nitrous temperature had risen. Siebold and Alsbury shouldered their parachutes and stepped into SpaceShipTwo. Saling arrived at the airport with her children. It was the kids’ first time watching Alsbury fly the spaceship.

WhiteKnightTwo and SpaceShipTwo zoomed off the runway. They flew about a hundred and fifty miles northeast, alongside a craggy mountain range streaked with purple and green mineral deposits. After reaching Death Valley, and still ascending, they looped back toward the release point. Stucky, in mission control, was watching the cockpit video and listening over the radio as Siebold and Alsbury ran through their checklists.

Alsbury: “Seat belts and shoulder harnesses?”

Siebold: “Snug.”

Alsbury: “Rocket burn timer?”

Siebold: “Set and verified.”

Alsbury: “Stick?”

Siebold: “Stick is forward.”

The pilots flooded their masks with oxygen, in case of an emergency. Neither was wearing a pressure suit.

Alsbury armed the release switch, and the spaceship dropped from WhiteKnightTwo. He fired the rocket. “Good light,” Siebold said, his voice reedy from the onset of g-forces. A moment later, following Stucky’s protocol, Alsbury announced their airspeed: Mach 0.8. They were in the transonic zone. Everything was going well.

“Yeehaw!” Siebold cried out.

Then Alsbury did something inexplicable. “Unlocking,” he said. He began reaching for a lever that controlled the locks on the feather.

Stucky hoped that he’d either misheard Alsbury or failed to notice that the spaceship had passed the transonic zone. He checked the Machmeter on the main display screen, and saw that the speed was still below Mach 1. His body seized: without the locks in place, aerodynamic forces would push the feather up, creating a tremendous amount of drag and shredding the spaceship in midair.

He lunged at the call button, intending to scream, “Don’t!”

Siebold grunted in agony. The audio feed stopped, and the video froze mid-frame. An engineer looked up from his console and gave Stucky a searching look.

Stucky said, “They’re gone.”

He raced to the roof, but streaks of clouds to the north obscured his view of the sky. He couldn’t stop thinking of the video feed’s final image: Siebold and Alsbury, slumped forward in their seats from the sudden deceleration. On the tarmac, Saling and Siebold’s wife, Traci, were ushered into a nearby building and informed that one man had apparently survived; the pilot of the “chase plane” trailing SpaceShipTwo had spotted a parachutist, who had waved. But it wasn’t clear which man was still alive. Saling asked a friend to take Ainsley and Liam home.

The breakup occurred twenty-five or so miles north of Mojave, at about forty-six thousand feet. “Bad stuff happens at those altitudes,” Bill Thornton, a retired Air Force brigadier general, told me. “It’s about minus sixty degrees. There’s no oxygen up there.” Pilots have survived exposure to such altitudes, but their experiences have been brutal. In 1959, a Marine F-8 Crusader pilot survived after ejecting at forty thousand feet into a thunderstorm, though his ears, nose, and mouth were oozing blood. In 1976, an Air Force SR-71 pilot bailed out at seventy-nine thousand feet. He was wearing a pressure suit, which saved his life.

As SpaceShipTwo disintegrated, Siebold heard a loud noise as the wings, the tail booms, the rocket motor, and the cabin tore away from the cockpit. Miraculously, he slipped out of his seat, and moments later his parachute automatically deployed. His eyes burned and he gasped for oxygen as he fell to Earth. He landed in a creosote bush near a dry lake bed. When E.M.T.s arrived, in a helicopter, they braced his neck and administered oxygen. His collarbone was broken, and his right arm, which was fractured, was bleeding through his flight suit. At the hospital, a doctor removed fibreglass from Siebold’s left cornea.

Stucky got into an airplane with another pilot and surveyed the crash site. Later, he returned in his S.U.V. to help search for wreckage and for Alsbury. The cockpit had crashed twenty miles north of Mojave, making a nine-foot-wide, three-foot-deep crater in the dirt, and though Alsbury’s torso remained strapped in his seat, affixed to the cockpit, human remains and vehicle fragments were scattered widely. One scrap of the spaceship landed on a golf course fifty miles away. Employees, investigators, and pathologists from the coroner’s office fanned out across the desert, collecting what they could.

Stucky returned to the crash site nearly every day for weeks, nominally searching for wreckage. Agin, who joined him on weekends, said, “We didn’t want pieces of the spaceship to end up on eBay.” But the trips also offered him a form of therapy. “In my line of work, and in my line of extracurricular activities, I’ve lost dozens of people I know,” he told me. In 1992, he had watched a good friend, a Navy lieutenant, crash short of the runway at Edwards Air Force Base, killing himself and a crew member. In 2005, another friend, a nasa test pilot, was doing acrobatic maneuvers when the cockpit canopy came loose and knocked her in the head; she crashed and died. But this was different. Alsbury had been both his wingman and his co-pilot, and during the previous year he’d become Stucky’s closest friend. “Nothing’s affected me quite like his death,” he told me. He couldn’t stop thinking about his friend’s mistake—why Alsbury had “skipped a chapter in the hymnal.”

He wasn’t alone in his grief. The day of the crash, Jim Tighe, who had led the engineering team at Scaled Composites, broke down when he saw Saling in the parking lot, repeating, “I killed Mike!” Virgin Galactic flew in a pastor and a psychologist to counsel distraught employees.

The business press began asking if Virgin Galactic would survive. Customers demanded refunds. The Independent quoted an asset manager in Switzerland as saying, “I want out.” A lot of the coverage was breathless and inaccurate. Joël Glenn Brenner, a former Washington Post reporter who was researching a book about commercial space travel, told CNN, erroneously, that the crash had been caused by a rocket malfunction: “The rocket stopped, and then within one second it restarted, and that is when it exploded.” She said of Virgin Galactic, “They took this pilot’s life.”

Doug Messier, an aerospace blogger based in Mojave, published posts accusing Virgin Galactic of being cavalier about safety. In the comments section, Stucky replied angrily: “In the last couple of weeks I’ve lost a great friend and a great spaceship. Almost immediately you and other pseudo-journalists were quick to lay blame on the rocket motor and perceived programmatic pressures, both of which couldn’t be further from the truth. You act horrified about unconfirmed testing schedules and yet never compare them to other manned rocket programs—either historical or planned.”

Stucky wondered if his days flying SpaceShipTwo were over. After the crash, Virgin Galactic took over the program fully from his employer, Scaled Composites. When test flights resumed, only Virgin Galactic pilots would be involved.

Then, five weeks after the accident, Virgin Galactic’s president, Mike Moses, asked to stop by Stucky’s house. Moses is a cheerful, hypereducated man with an Apollo-era flattop. He spent thirteen years with nasa before joining Virgin Galactic, in 2011. He has experienced the triumphs and the tragedies of spaceflight. He can recount eating his lucky breakfast—Mountain Dew, a strawberry Pop-Tart—on launch days at Cape Canaveral, and he can also vividly recall scouring forests in East Texas for debris after the Columbia explosion.

Moses, who felt certain that Virgin Galactic would emerge from the calamity a better company, offered Stucky a job as the fifth member of Virgin Galactic’s pilot corps, alongside Dave Mackay, the Scottish flier, who was a Royal Air Force veteran; Mike Masucci and Todd Ericson, former U.S. Air Force test pilots; and C. J. Sturckow, a retired marine and a former nasa astronaut, who’d flown four Space Shuttle missions and had logged more than twelve hundred hours in space. Stucky immediately accepted.

As Moses was leaving the house, he passed a deflated red balloon hanging in a frame on a wall. Attendees at one of Alsbury’s memorial services had released red balloons into the sky. A few days later, Stucky and Agin were driving down a desert highway when they noticed one snagged on a tumbleweed; they took it home. Someone had written on the balloon, in black marker, “Your spirit will always inspire us to new heights.”

Moses predicted that his team would need about two years to build another spaceship and resume flight testing. He knew that the delay put them at risk of losing the commercial space race. But another accident could put them out of the running altogether. In April, 2015, after Blue Origin completed a successful test of New Shepard, its space-tourism rocket, Moses said to me, “I see that and go, ‘Crap!’ Because I look at their timeline and see that they have a good shot at beating us.”

He is a relentless optimist, though, and decided to view the extra time as an opportunity to build an even better spaceship. He directed his engineers to reassess every system on the vehicle, from the rocket motor and the landing gear to the feather and the seat belts. “It’s not that Scaled was wrong,” Moses said. But its specialty was building prototypes, and Virgin Galactic was trying to build a passenger spaceship. “They were asking, ‘Is it safe for twenty flights?’ We’re asking, ‘Is it safe for a thousand flights?’ ”

Moses was highlighting the greatest engineering challenge for his team. SpaceShipTwo needed to be supple enough to break the sound barrier, light enough to reach space, strong enough to avoid breaking up on reëntry, and tough enough to make the journey once a week for years. “Reusability,” to use the industry watchword, has hardly been a priority in space-travel engineering. For fifty years, nasa, the Department of Defense, and government-contracted launch providers treated rockets as expendable. Even the most seasoned member of the Space Shuttle fleet, Discovery, went to space only thirty-nine times. Moses’s business model anticipated each SpaceShipTwo craft making at least five hundred missions.

Virgin Galactic’s main hangar, known as faith (Final Assembly, Integration, and Test Hangar), is a corrugated-metal structure covering an area larger than a football field. On the morning of January 4, 2015, Bryon Holbrook, a production manager with the company’s manufacturing subsidiary, stood in front of a scaffolded fuselage, rallying his team. A patchily colored husk was all that existed of the new spaceship. He told the group that they had exciting work to do. “It’s go time,” he said.

Stucky (left) at his winging ceremony, or flight-school graduation, in 1982. Photograph courtesy Mark Stucky

He pointed to a whiteboard scrawled with dates and the names of mechanical parts, and then at a tail boom lying on the ground. “We got to hang this thing very, very soon,” he said. I followed Holbrook to a second hangar, where techs in bunny suits were cutting, molding, and curing pieces of carbon fibre—the primary material used to build SpaceShipTwo and WhiteKnightTwo. “Carbon-fibre composites don’t fatigue like metal does,” Moses told me, adding, “One of the beauties of carbon-fibre-composite airplanes is that you can literally tape and glue parts on and off.”

Morale had been flagging, Holbrook admitted. Employees were hearing rumors that Branson was pulling out. “This crash is not going to define me,” Holbrook said. “Are we really going to go to Alsbury’s kids and say, ‘Your dad died for a program that ended’? No way.”

In the second hangar, a tech pulled him aside. “I need people,” she said. She was missing deadlines because she was short-staffed. Building the spaceship’s frame was labor-intensive: you had to bind together sheets of honeycombed carbon by applying resin, cut the sheets into shapes with laser-guided precision, and bake each piece in a Celotex oven.

“That’s the hardest thing about this place—recruiting and retaining good people in the desert,” Holbrook said. Military vets like Stucky were used to drab locales, but many techs and engineers found the Mojave wasteland stifling. Holbrook’s wife, Brandi, kept asking him for schedule updates, hinting at her desire to move on. He told her that he at least wanted to see SpaceShipTwo get to space.

One night, when I joined them for dinner, Brandi said to her husband, “You keep extending our sentence.”

“This is the most fulfilling thing I’ve ever done in my life!” he told her.

Their kids were stuck in a terrible school, she said.

“They’re in kindergarten,” he said.

A month after the dinner, Holbrook called me from the road. He’d just accepted a job in Colorado. “I was going to lose something,” he said. “Either the spaceship or my family.”

The night of the crash, Stucky received a Facebook message from Dillon. “Glad you are OK,” his son wrote. “I was tripping out for a bit. Sending my condolences for your colleagues.” Stucky hadn’t heard from Dillon in almost a year, and had been desperate to reëstablish contact. But the tragedy had left him exhausted and despondent. “Hmm, let’s see,” Stucky replied. “Son ignores father and refuses to include him in his life but would be ‘tripping out’ if father might be dead. Sure sounds logical to me.”

Not surprisingly, Dillon didn’t write back. Seven months passed. In May, he ended the silence, telling Stucky, “I’m pretty tired of being estranged.” He drove up from L.A. for brunch. Things felt awkward, and so they talked about a subject that seemed safe: flying. Dillon was interested in learning how to paraglide. Stucky offered to mentor him. They started meeting up on weekends.

Meanwhile, construction was proceeding on the new spaceship. On May 21, 2015, crew members standing on cherry pickers removed the final piece of scaffolding from the new iteration of SpaceShipTwo. At an employees-only ceremony at faith, George Whitesides, Virgin Galactic’s boyish C.E.O., reminisced about arriving in Mojave in the late aughts, when Virgin Galactic “was just a couple of words.” Now, he said to applause, “it’s a real fucking spaceship company!”

Two months later, Whitesides flew to Washington, D.C., for a meeting with the National Transportation Safety Board. Investigators at the agency had spent nine months probing the crash. Whitesides was anxious: a critical report would ruin Virgin Galactic’s reputation. In recent months, it had distanced itself from its former partner, Scaled Composites, and in a written statement to the agency it had noted that “Scaled Composites was responsible for all aspects of the flight-test program at the time of the accident.”

Whitesides’s worries were misplaced. The agency said that the crash was the result of pilot error.

The N.T.S.B. investigation reawakened raw feelings. One morning, Stucky said to me, “If I had been flying with Mike that day and heard him say, ‘Unlocking,’ I think I could have stopped him in time.” Agin said, “I will always believe that if Mark had been in that spaceship that they wouldn’t have crashed.”

In September, 2015, he and Mackay, the Scottish pilot, delivered a presentation about the crash at the annual symposium of the Society of Experimental Test Pilots. On the first three powered flights of SpaceShipTwo, Stucky said, he had imposed “sterile cockpit rules,” because he “did not want extraneous calls during boost and other high-workload portions.” But, Mackay noted, “Scaled gave their pilots-in-command the leeway and authority to run their cockpit as they saw fit,” and this failure to “impose a rigid set of standard operating procedures” had “created an environment where callouts and actions could be missed both in the cockpit and in the control room.”

Peter Siebold, who had recovered from his injuries, was in the back of the banquet hall. Neither Stucky nor Mackay mentioned his name, but Stucky privately faulted him for his unnecessary shout of “Yeehaw!” during the boost, and for not stopping Alsbury from unlocking the feather.

After the presentation, Stucky and Siebold ran into each other by the coffee urns. “It’s too early,” Siebold said. They have hardly spoken since.

By February, 2016, construction on SpaceShipTwo was largely complete, and Branson wanted to celebrate. He and his family, several publicists, a production crew, journalists, and such celebrities as Harrison Ford and Sarah Brightman gathered at the hangar, which had been transformed into a club. Servers handed guests flutes filled with champagne and blue curaçao. At one point, as a fog machine started up and a d.j. played triumphalist dance music, a curtain parted, revealing the new SpaceShipTwo. It was towed by a white Land Rover, and Branson, whom the Times once called “a one-man publicity circus,” was poking through the open sunroof, blowing kisses.

The party was premature: Virgin Galactic wasn’t ready to fly again for another seven months. During that time, Stucky’s frustration with the engineers built. Some of them were drawing the wrong lessons from the crash, he thought, allowing a fear of failure to dominate their calculations. If they couldn’t live with some risk, they’d never roll the spaceship out of the hangar.

There was no such timidity, Stucky had heard, at rivals like SpaceX. Elon Musk reportedly scolded and overworked his employees. I asked Branson, whose companies are famously collegial, if he’d contemplated taking a harder line. “I don’t think that works in the long run,” he said. “We actually attract a lot of people from these other space companies—and I’m not naming names—who don’t necessarily enjoy that atmosphere.”

Virgin Galactic finally set a date for the first flight: September 8, 2016. Stucky would pilot SpaceShipTwo, but the test was a captive-carry flight, so he wouldn’t need to do much, unless WhiteKnightTwo unexpectedly dropped the spaceship in midair.

On the morning of the flight, Stucky and others were gathered around a conference table in the hangar, making final preparations, when a crewman announced bad news: an hour earlier, he’d been inspecting the spaceship with a flashlight, and noticed a one-inch hairline crack along the spine of the vehicle, near the spot where it attached to WhiteKnightTwo. It might be nothing, or it might warrant scrubbing the flight.

“No pressure,” Moses said. “If it’s not good, we don’t go.” He told Mark Bassett, SpaceShipTwo’s project engineer, to take a few hours to analyze the crack.

Bassett returned ten minutes after the deadline. “Let’s start with the good news,” he said. Given the crack’s location, he’d determined that “its ability to propagate is very small.” He wasn’t sure what had caused the crack, or how long it had been there, but he didn’t feel that these small mysteries were significant enough to justify cancelling the flight.

Todd Ericson, the former Air Force test pilot, had become Virgin Galactic’s vice-president for safety, and he asked if anyone else had reservations.

“I can’t lie and say I’m not a little hesitant,” Wes Persall, a flight-test engineer who was assigned to fly aboard WhiteKnightTwo, said. “We’ve come a long way, and it would be a shame to do something now that would delay us even further.”

Persall had been friends with Alsbury, and had watched the breakup, in real time, on a high-resolution feed at Edwards Air Force Base.

Moses, sitting at one end of the table, had suspected that there would be “jitters,” as he put it, before the flight. He was contending with his own charged emotions. He’d recently found in his office a photograph of Stucky and Alsbury from the first powered flight, smiling and gripping hands. He broke down at his desk. “A man died, and his family was torn apart,” Moses told me. At the same time, Alsbury’s mistake had cost them dearly. If it hadn’t happened, Moses felt, Virgin Galactic would likely be flying tourists to space already. He told me, “Then you feel guilty that you feel just as bad about the program as you do about the people most affected. So you bury all this, because it doesn’t seem right to feel more, or as, sad about a thing as about a person.” He’d wrestled with similar feelings after the Columbia crash: “When I see a picture of the Columbia crew, I get a sadness, a feeling of great personal loss. But I also can’t not remember the six months we spent cleaning up debris in the forest. And that’s a whole different kind of hurt—a realization that the ship was gone and that the program was over.”

Persall couldn’t shake his concerns about the crack. He said that he’d watched enough training videos about taking risks seriously to know that he should listen to his gut.

Stucky in Iraq, in 2004, while on active duty with the Air Force. He watched a broadcast of SpaceShipOne’s launch from one of Saddam Hussein’s former palaces. Photograph courtesy Mark Stucky

Stucky spoke up. “On the devil’s-advocate side, what you don’t see in those videos is when they have these kinds of meetings and then they go up and nothing happens,” he said. With experimental vehicles, he added, this kind of thing happened on “practically every flight.”

Persall gave in, and the captive-carry flight proceeded. It all went fine.

Now that the SpaceShipTwo flight-test program had resumed, Stucky went on a diet and started attending yoga and kickboxing classes. He honed his flight skills on sailplanes, his paraglider, the simulator, and WhiteKnightTwo. To maintain his stick-and-rudder skills and his g-tolerance—his body’s ability to handle extreme gravitational forces—he regularly performed flips, rolls, and banks in an Extra 300L, a twin-seat aerobatic propeller plane owned by Virgin Galactic.

One day, he offered to take me up with him. We emptied our pockets in the faith locker room and put on parachutes. Tarah Castleberry, Virgin Galactic’s flight doctor, shared a technique that would help me avoid getting sick or passing out. “Pretend like you’re squeezing a walnut down there,” she said, referring to my gluteal muscles.

Stucky took off and corkscrewed above the airport until we reached about eight thousand feet. He then jerked the stick to the side, pulling five g’s. He held this for fifteen seconds. Next, he did half a loop; we were upside down, experiencing negative g. After fifteen seconds, he flipped the Extra right side up, and went straight into another five-g bank.

This routine wasn’t sadistic in intent: it had been designed by Virgin Galactic medics and pilots to achieve specific research and conditioning goals. Moses told me, “Usually, when you go to space, you see very high g”—during boost—“followed by long periods of zero g”—in space—“before you return to gravity. You’re up in space for at least a day or two, if not weeks or months. What’s unique for us is that we’re going to have high g followed by four minutes of zero g, followed by high g again. There’s no scientific data to show what will happen.”

On the Extra flight, midway through that initial, five-g turn, I experienced some pixelated tunnel vision, and felt like my helmet was pinned against the headrest, but it passed within seconds, as soon as Stucky pulled out of the bank. At one point, Stucky said, “This is something I saw on YouTube.” He rolled the Extra upside down, yanked the stick toward his lap, executing a three-quarter loop, and then pushed the stick forward. We began tumbling toward Earth, nose down. He held the dizzying maneuver for several seconds. I conjured the walnut.

He then applied power, eased back on the stick, and, like that, we were flying straight and under control. Later, he said of the tumbling trick, “It’s sort of like a Lomcovák”—a spinning acrobatic maneuver that, in Czech, means “profound shaking.” He did Lomcováks all the time, but was always looking to mix it up. Doing the same routine at the gym gets you only so far.

Flying on the Extra was valuable, but its cockpit was different from SpaceShipTwo’s. The flight simulator, conversely, could simulate the spaceship’s cockpit but not high g-loads. So in March, 2017, Stucky and two other pilots, Mike Masucci and C. J. Sturckow, travelled to the National Aerospace Training and Research Center, outside Philadelphia. The facility, known as nastar, features a massive centrifuge that spins at about sixty miles an hour, creating gravitational loads that can exceed nine g’s. The technicians attached a one-man capsule to the end of a twenty-five-foot-long steel arm. The capsule’s displays evoked the experience of being inside SpaceShipTwo’s cockpit.

On the first day of training, Stucky rehearsed the boost portion of a rocket-powered flight twice. He had worn his flight suit, then felt embarrassed. “There’s something about wearing a flight suit with tennis shoes that makes me feel like Joey Bag o’ Donuts,” he said later. Masucci agreed with him: a flight suit should be worn only in an airplane, with combat boots.

Although the pilots felt that their minds were as acute as ever, their bodies were past their primes. Even Stucky’s eyesight was getting worse; he’d recently drilled pinholes into his visor and, using a needle and thread, stitched reading glasses into place. “My days have got to be numbered,” he told me. Piloting SpaceShipTwo would likely be his last hurrah.

G-forces come in three categories: gx are felt sagittally, like a bullet hitting the heart. Gy-forces come from the side, and gz are transferred vertically. Gz-forces can feel particularly intense, because blood rushes to and from the brain. Based on computer calculations, SpaceShipTwo pilots would feel up to five gz during reëntry, and customers could feel up to four gz for a few seconds. This would be manageable, I was told. Virgin Galactic engineers had designed a reclining seat that will redirect g-forces, making the experience more pleasant, and each passenger will receive a customized flight suit with a towelette in one pocket, in case of motion sickness. Beth Moses, a former nasa engineer, will oversee the process of preparing passengers for flight. (She is married to Mike Moses.) Occasionally, she said, “passengers may get some grayout,” a loss of color perception, which is the mildest form of g-induced stress. “And we may, once in a blue moon, have someone who’s on the edge of having more than grayout”—ranging from tunnel vision to brief “g-loc,” or loss of consciousness. But, she added, “we’re going to show them how to keep some blood in the back of their eyeballs.”

At the nastar facility, Masucci told the other pilots, “I’ve never had full-on G-LOC.” Stucky said that he’d had it “only once”—on his first solo flight, in 1981. He recounted climbing to nine thousand feet in a T-34 prop plane, flipping it upside down, and pointing its nose at the ground. His plan was to pull the stick back, allowing the T-34 to make a vertical U-turn. But while he was plummeting, he said, things went awry: “Here comes the tunnel vision, marching in really slow. All I’m looking at is the g-meter. Then that disappears. Then I lost all vision. Before I know it, I’m like this”—he pretended to pass out and jolt awake. He went on, nonchalantly, “At about six thousand feet, I added power and flew home.”

The others looked at him with amusement and disbelief. “I figured you won’t kick me out now!” he said.

That afternoon, Stucky got back in the centrifuge to practice entering, and recovering from, a “departure”—a loss of control. He pushed hard into a dive, and started spinning and tumbling with dizzying velocity. After ten seconds of wild spinning, the centrifuge froze, leaving Stucky hanging upside down by his shoulder straps. Richard Leland, at that time the head of the nastar facility, turned to me and said, “When the machine thinks that something is going to happen that would either injure the pilot or cause damage to the machine, it will automatically stop.” Stucky, always pushing the limits, had essentially made the machine go “tilt.”

The pilots began packing up, and Stucky read aloud a breaking-news item on his phone: Jeff Bezos had appeared at the Satellite 2017 conference, in Washington, D.C., to promote Blue Origin’s latest rockets. “I just keep waiting for them to announce that they flew humans to space,” Sturckow said.

Stucky was about to lose another race. In 2009, he and an Air Force lieutenant colonel, Jack Fischer, had made a bet about which of them would be the first in space. Stucky had just joined the SpaceShipTwo program; Fischer had recently been named a nasa astronaut. The victor would receive a free meal at Domingo’s, a Mexican restaurant, near Edwards Air Force Base, that was popular with test pilots.

In July, 2016, Fischer informed Stucky that, within the year, he and a Russian cosmonaut were scheduled to visit the International Space Station. They would launch from a site in Kazakhstan. “The flight/race/bet is ON,” Fischer wrote.

Stucky felt joy, jealousy, and a surge of motivation. He found it infuriating that nasa had become reliant on Russian rockets to transport American astronauts into space. The situation underscored the urgent need for private spaceflight platforms like Virgin Galactic. He and Fischer exchanged mementos in the mail. Stucky sent him one of Mike Alsbury’s old flight-suit nametags.

On April 20, 2017, a month after the Philadelphia trip, Stucky sent me a text message: Fischer had just won the bet. After Fischer landed, he sent Stucky two photographs of Earth that he’d taken through a porthole of the International Space Station. One image featured Alsbury’s nametag in the foreground. “Everyone who is a space explorer takes a big risk because we think it’s worth it,” Fischer told me. “You want to try and honor that brotherhood any way you can.”

Stucky printed the photograph and gave it to Michelle Saling, Alsbury’s widow. One morning last fall, he and Agin met her at the Denny’s in Mojave. Nearly three years had passed since the accident. Saling and her kids were struggling, she told me: “No matter how strong I try to be, and how hopeful I try to be for my children, our lives are not complete without him.” They’d kept living in Tehachapi, a town twenty miles west of Mojave, to be close to their friends, but the roar of jet engines constantly reminded her and the children of Alsbury.

Saling, a tough, petite woman with straight brown hair, confessed to Stucky that she’d never been to the crash site. After they paid the check, Stucky and Agin took her there. They split up, drifting silently into the desert. A recent storm had shifted the top layer of earth, exposing more artifacts from the crash: a bundle of wire, shards of cockpit glass.

Saling picked up a piece of the wreckage, clutched it to her chest, and began to cry. Stucky put his arm around her. He offered to drive Saling back to Mojave, but she declined, and said she wanted to go see the other impact points.

In the car, he told her about some of the training he’d done in the centrifuge. “I know you don’t want to hear that something good came of all this,” he said. But one lesson he’d taken from the crash was the importance of scripting every word and action on a test flight. While in Philadelphia, he and the other pilots had each committed the same blunder: calling out “trimming” when they were still subsonic. Stucky explained to Saling that if the pilots trimmed—went sharply nose up—before passing Mach 1, “it would aggravate the transonic pitch-up.” After returning from Pennsylvania, Stucky had asked the engineers to adjust the altitude and airspeed dials so that blue lights began glowing after the spaceship went supersonic; this color prompt would indicate that it was safe to begin trimming.

“Maybe Mike’s death saved eight people from dying on a later flight,” Stucky told Saling. “I’m not telling you that to try and make you feel better. Just that we’ve made some serious changes. Because ninety-nine per cent isn’t good enough.”

Saling thanked him. It was oddly comforting to hear examples of other pilots’ fallibility. Her husband was not the only one prone to skipping a chapter in the hymnal.

Last October, Richard Branson appeared at a conference in Helsinki, and was asked about Virgin Galactic. “We are hopefully about three months before we are in space, maybe six months before I’m in space,” he said.

Branson, who isn’t involved in daily decisions at the company—he gets regular updates from George Whitesides, the C.E.O.—has a history of issuing unrealistic assessments. In 2005, he announced plans to build a “spaceport” near Truth or Consequences, New Mexico; once SpaceShipTwo completed its flight-test program, he said, Virgin Galactic would move there for its commercial operations. “New Mexico will be known around the world as the launchpad for the new space industry,” Branson said. Construction on the site, Spaceport America, was completed in 2011, but it remains unoccupied.

Branson admitted to me, “It would be embarrassing if someone went back over the last thirteen years and wrote down all my quotes about when I thought we would be in space.” But he also defended his approach: “If you are an optimist and you talk ahead of yourself, then everybody around you has got to catch up and try to get there.”

His Helsinki appearance coincided with a particularly promising run of Virgin Galactic test flights. In December, 2016, three months after the captive-carry flight, Stucky completed the first glide flight. By August, 2017, Virgin Galactic had logged five more. Each success brought it closer to resuming rocket-powered tests. The company was pleased by its comeback, but Branson—who kept reading about rivals leaping ahead—was as restless as ever. In December, Blue Origin launched its New Shepard rocket-and-capsule configuration into space with a mannequin on board.

Around this time, Virgin Galactic weathered another series of setbacks. A technician accidentally damaged the bonding on SpaceShipTwo’s body with a blast of compressed air that he’d applied to remove drill shavings; repairs took weeks. Then the engineers discovered a problem with the horizontal stabilizers, or h-stabs, which are attached to the tail booms and control pitch and roll at supersonic speeds. One day, during ground tests, the h-stabs suddenly stopped working. It took months to solve the problem. In late December, Moses wrote a memo to employees: “We will not push blindly towards dates on a calendar. But I think you all can feel it, like I do, that the thing we all came here for—flying people to space from Spaceport America—is within reach.”

Two weeks later, Stucky completed the final glide test. It was time for a rocket-powered flight. After more than three years, Virgin Galactic had fought its way back to where it had been on the morning of the crash.

Branson started training, playing more tennis and rehabbing a shoulder that he’d injured while kitesurfing. I asked him if he and his wife had discussed the possibility of his meeting a tragic end. In the nasa Space Shuttle program, one in sixty-eight flights resulted in a fatal crash. “We’re a family that believes you should live life to its fullest,” Branson said. “I’ve done a lot of ballooning trips. My son climbed the Matterhorn a couple of years ago. We’ve been born under a lucky star, I think.”

As adventurous as Stucky was, he didn’t believe in lucky stars, or lucky breakfasts. “The only superstition I have is not to be superstitious,” he said. The same empiricism led him to keep urging Virgin Galactic engineers not to be spooked by the past. When some of them proposed redesigning the landing gear to make it stronger, Stucky argued that this was excessively cautious, and would cause needless delays. To make his case, he retrieved the destroyed spaceship’s landing gear from storage, and demonstrated that, after nearly forty flights and a catastrophic crash, the gear remained as good as new.

A contentious debate erupted over how long to burn the rocket. Stucky found no reason for inching into space, and wanted the rocket to burn long enough to get him well beyond the transonic zone. He suggested forty seconds. In an e-mail, one engineer expressed concern about overheating and proposed twenty-two seconds. Another, noting that avoiding “potential disaster” was paramount, recommended fifteen.

Stucky recoiled at what he perceived as an implication of recklessness. “Your shotgun e-mail makes it look like I’m trying to run a ‘Damn the torpedoes, full speed ahead’ approach to flight testing,” he wrote back. “To paraphrase Harrison Storms, the North American Aviation project manager for the X-15 as well as Apollo, we need to work with thoughtful courage and not be blinded by fearful safety.”

At one point, Stucky discussed burn times with Burt Rutan, SpaceShipOne’s creator, who had retired and moved to Coeur d’Alene, Idaho. “You’ve got an airplane that should be able to run a full burn,” Rutan told him. “So plan for a full burn.” He reminded Stucky that the hybrid-fuel motor could be turned off by pressing a button. But, if things were going well, why not keep soaring higher? “You’ll enjoy that next minute of burn,” Rutan said, smiling. (Chuck Yeager, in his memoir, describes the feeling of riding a rocket out of the atmosphere: “You’re bug-eyed, thrilled to your toes, and the fighter jock takes over from the cautious test pilot. Screw it! You’re up there in the dark part of the sky in the most fabulous flying machine ever built, and you’re just not ready to go home.”)

Rutan reminded Stucky, “It might be the only chance you have to be an astronaut. What are they going to do—fire you? Fuck no!” He laughed. Then, turning sombre, he made one request: “Promise that you will never unlock the feather during boost.”

On April 5, 2018, the day of the rocket-powered flight, Stucky and Agin woke together at 4 a.m., but he drove to Mojave alone. Her phone soon vibrated. “Any chance you can be here by 0645?” he texted. He’d left his flight card at home. She got to the hangar just in time. After she gave Stucky a kiss, she was escorted to a viewing area by the runway. Hundreds of employees and family members cheered at takeoff, with Masucci in WhiteKnightTwo and Stucky and Mackay in SpaceShipTwo. Agin tried to mask her anxiety. “It’s a little scary,” she’d told me the previous night. “Because of Mike, and because it’s just been so long coming. I’ll be glad when this one is behind us.”

At forty-five thousand feet, Masucci began his countdown: “Three, two, one. Release, release, release.”

Stucky waited until there was sufficient separation from WhiteKnightTwo, then called, “Fire!” Mackay lit the rocket. The thrust from the boost pushed them back in their seats—an exhilarating sensation that made Mackay feel that he was on a magic-carpet ride.

The team had reached a compromise on burn length: thirty seconds. Sensors attached to Stucky’s body indicated that, in the first seconds after the rocket fired, his heart rate jumped by forty beats a minute. Yet he felt eerily calm—time seemed to be stretching to let him think. Ten seconds into the burn, SpaceShipTwo was supersonic. Stucky began trimming the h-stabs, steadily increasing the vehicle’s pitch until it reached sixty-eight degrees. He and Mackay were travelling at Mach 1.8—about twice as fast as a Tomahawk cruise missile. Outside the vehicle, the light was draining from the sky, turning it a deep, muddy blue. The spaceship had cleared sixty thousand feet.

Stucky suddenly felt the wings tipping, as if the spaceship were about to roll upside down. “A little rolly there,” he said. He was straining to keep the wings level. He knew that he should abort—manually shut down the rocket motor—before he lost control of the spaceship. Entering a spin, or a tumble, at supersonic speeds would be hard to recover from. But, electrified by the ascent and believing that he could hold the spaceship steady, he let the motor burn.

A moment later, he felt the vehicle rolling even harder. “Ahhh! ” he groaned. The spaceship was slipping beyond his control. He commanded Mackay to push the button that would instantly cut off the motor.

Mackay was leaning forward to do so when the rocket’s onboard timer hit thirty seconds; the motor automatically shut down.

Stucky got the craft under control and looked out his window. The Earth’s bright-blue surface filled his porthole. It was a stupendous sight: the outer edge of the atmosphere was dancing with wispy tendrils. The spaceship was now at eighty-four thousand feet—higher than he’d ever been. He could now testify to the awesome power of the “overview effect.” And yet, he suddenly realized, he wasn’t supposed to be looking down at Earth. This was the plan for tourist flights, but for this test the craft was meant to stay upright, allowing him to see only the blackness of space. SpaceShipTwo had somehow rolled over without his noticing.

“Oh, shit,” Stucky said. “The gyros are messed up.” For unknown reasons, they indicated that the spaceship was right side up.

“Totally,” Mackay confirmed.

Hurriedly, Stucky attempted to right the ship by blasting thrusters of high-pressure air, which was stored in the wings and was used to orient the vehicle in low-gravity environments. Then he instructed Mackay to unlock and raise the feather. As it went up, the spaceship righted itself, just as it had on Stucky’s harrowing glide flight seven years earlier. The same innovation that had contributed to the 2014 crash was, when properly deployed, a godsend.

Stucky searched for a stable guide on the horizon. “I got the moon,” he said. He glided over the California desert, toward the constellation of dry lake beds below.

Dillon, who was on the tarmac in Mojave, was now on contract with Virgin Galactic as a videographer. He powered up a drone and zipped it along the runway to film SpaceShipTwo as it made its final approach. The spaceship landed at 9:14 a.m.—thirteen minutes after its release from WhiteKnightTwo. “That was about the coolest thing I’ve ever seen,” Dillon said afterward.

Michelle Saling was on her way to her daughter’s school when she saw WhiteKnightTwo in the distant sky, its twin contrails like walrus tusks. She shed tears of joy for Stucky—“Mikey would be happy,” she texted him—but also felt an upwelling of sadness. “Seeing that just intensified my sorrow that he’s not here,” she told me.

Jack Fischer, the nasa astronaut, posted a congratulatory tweet to “the whole @virgingalactic team,” adding that Stucky “was slipping the surly bonds like a boss!” He was alluding to “High Flight,” a 1941 poem by an aviator named John Gillespie Magee, Jr. It begins, “Oh! I have slipped the surly bonds of Earth / And danced the skies on laughter-silvered wings.”

Touching down, Stucky and Mackay climbed out of the cockpit, pumped their fists, and high-fived the crew. Stucky crossed the runway to where his colleagues were whistling and applauding. He hugged Agin. George Whitesides handed him a microphone.

“I don’t know where to start,” Stucky said. “Some of us have been waiting years to do that again!” Not only had they resumed launching manned rockets; they were flying them. And, for the first time, Virgin Galactic had done it all on its own: with its pilots, its rocket motor, its spaceship. “Richard has been waiting longer than all of us,” Stucky said. “Hopefully, we gave him a good flight.”

Branson and his grandchildren were huddled around an iPad at their mountain lodge in Verbier, Switzerland, watching a live stream of the flight. At the end of the rocket-motor burn, the room erupted with delight. “Artie, my three-year-old grandson, asked me why I was crying when everyone else was cheering,” Branson recalled. “It was just such a beautiful moment.”

He knew that Virgin Galactic still faced plenty of challenges. After a few more powered flights—on July 26th, Mackay and Masucci completed a forty-two-second rocket-powered flight, reaching a hundred and seventy thousand feet—the pilots would go all the way into space. Once that goal was met, they’d need to make several repeat flights, in order to assure the public that SpaceShipTwo was ready to begin commercial service. Branson, who had been funding Virgin Galactic for fifteen years, felt that redemption was finally near. “We’ve proved skeptics wrong,” he said.

He estimated that he had spent nearly a billion dollars on the program, all of which he expected to recoup. “There are, we believe, millions of people who would love to go to space, and we want to tap into those people,” Branson told me. “If you can create the best—the best hotel chain, the best clubs, the best spaceship company—it’ll become very valuable.” As of May, he valued Virgin Galactic and a satellite-launching spinoff, Virgin Orbit, at “some billions of dollars,” but said that they could soon be worth “many billions.”

Branson noted that the technology developed in mastering suborbital space tourism could be extended to other industries. Perhaps Virgin Galactic rockets would help passenger planes make transoceanic flights in record time. He also had plans to build “a vertical-takeoff vehicle”—a battery-powered flying car.

After Stucky concluded his remarks, he passed the microphone to Mackay, who declared, “I want to do that again!” He and Stucky relished their good fortune. Customers had promised to pay two hundred and fifty thousand dollars to experience the overview effect once. Stucky, Mackay, and the other pilots could soon be doing it once a week. The most experienced nasa astronauts, Jerry Ross and Franklin Chang-Díaz, had completed only seven spaceflights each.

There was a lot to review before the next flight. Among other things, the team needed to investigate why the gyros had flipped. (As it turned out, there had been a glitch in the gyros’ software; the manufacturer had issued a patch, but hadn’t indicated that it fixed a major problem, so Virgin Galactic hadn’t installed it.) But now it was time to celebrate the skill of pilots who could handle such a vertiginous surprise. Stucky and Mackay went into the hangar, and Mackay poured them glasses of single-malt Scotch.

After a while, Mackay went to the locker room and returned in jeans and a polo shirt. Stucky was still sipping Scotch in his flight suit when Ericson, one of the pilots, walked by and proposed getting some food. “Denny’s?” he asked.

Mackay glanced at Stucky and said, “You’re not going to Denny’s like that, are you?” ♦