On Wednesday afternoon, Mark Stucky left work early and went to his stepdaughter’s place to hang window blinds. Stucky, the lead test pilot at Virgin Galactic, was expecting to fulfill a lifelong dream—flying a rocket ship into space—the next morning, but he was trying not to make more of it than necessary. And so, after he put up the blinds, he drove home, had an early dinner, soaked in his hot tub, and was asleep by eight.

He was up before his 3 A.M. alarm, not because he was nervous—a bout of butterflies had come and gone earlier in the week—but, as he told me later, “Because I was in the zone.” He ate a cup of yogurt on his way out the door. Sometimes, before test flights, he listened to music. On Thursday, he drove in silence.

Stucky had dreamed of travelling into space since he was three years old, when he and his dad watched on TV as John Glenn orbited Earth. He applied for NASA’s astronaut program several times, and got close, but never made the cut. When, in 2009, he was hired as a test pilot by Scaled Composites, an aerospace company on contract to design, build, and test Virgin Galactic’s spaceship, he thought he might be close. But program delays and a crash, in 2014, which killed his best friend, Mike Alsbury, and left the spaceship in pieces, made Stucky wonder if he would ever get there. Now, at the age of sixty, he was about to attempt to soar two hundred and sixty-four thousand feet, or fifty miles, above the surface of Earth—beyond the boundary of what the U.S. government deems space.

It was a clear, crisp morning in Mojave, California. Nicola Pecile, who was piloting the mothership, WhiteKnightTwo, which would carry the rocket ship, SpaceShipTwo, up to its release point, spotted a comet in the southwest sky. Venus shone brightly overhead. By 7 A.M., about a thousand people, including officials with the Federal Aviation Administration and Virgin Galactic’s billionaire founder, Richard Branson, had gathered on the flight line. Eleven minutes later, WhiteKnightTwo sped down the runway and took off, with Stucky and his co-pilot, the former NASA astronaut C. J. Sturckow, below, in SpaceShipTwo. George Whitesides, the C.E.O. of Virgin Galactic, said he hadn’t felt as anxious in years: “This is right up there with childbirth in terms of nervousness levels.”

As WhiteKnightTwo climbed, Stucky ran through his final checklists. He had flown five previous powered flights, burning the hybrid rocket motor for just more than thirty seconds, coasting above a hundred thousand feet, but on Thursday he planned to burn the motor for almost a minute—enough, it was hoped, to propel SpaceShipTwo to the fifty-mile boundary.

An hour after takeoff, WhiteKnightTwo, now forty thousand feet above the desert, dropped the spaceship and banked away. Then, on Stucky’s command, Sturckow fired the rocket and they were off. Once they broke the sound barrier, Stucky began trimming the horizontal stabilizers, increasing the vehicle’s pitch, until the nose was pointing nearly straight up. Twenty seconds. Thirty seconds. Forty seconds. Even though they were pushing into “unknown, uncharted territory,” the longer they burned the rocket motor, the better SpaceShipTwo seemed to perform. “She felt like a thoroughbred,” Stucky said.

After sixty seconds, Sturckow switched off the motor, letting SpaceShipTwo slice through the last remnants of atmosphere. While the sky darkened around them, sunlight filled the cockpit. Absent gravity, Stucky removed his glove and let it float around for a moment.

Back down on the flight line, Enrico Palermo, the president of the Spaceship Company, the subsidiary of Virgin Galactic that built SpaceShipTwo, stood at a lectern onstage, calling out the vehicle’s altitude:

“Two hundred and forty thousand feet.”

“Two hundred and fifty thousand feet.”

“Two-sixty.”

“Two hundred and . . .”—he paused, awaiting confirmation from mission control—“two hundred and sixty-four thousand feet.”

The crowd whooped and cheered. “Still going up,” Palermo said. “Apogee: two hundred and seventy-one thousand feet.”

Todd Ericson, one of the test pilots and Virgin Galactic’s vice-president for safety, reached over and gripped Whitesides’s hand. “We’re in space,” Ericson said.

Fifteen minutes later, Stucky and Sturckow landed, stepping out of SpaceShipTwo to enthusiastic applause. Branson, wearing a distressed-leather bomber jacket, took the stage and said, “Who enjoyed that?” The outline of a single tear streaked the side of his face—it was a moment of tremendous joy, catharsis, and relief for him, the team, and their families. Stucky’s wife, Cheryl Agin, shed tears throughout the entire flight.

Stucky and Sturckow joined Branson onstage. Stucky reached into the calf pocket of his flight suit and presented Branson with a blue-and-green stress ball, modelled on the Earth, that had just been in space. He then fished out a small, black jewelry box, which contained an engagement ring that belonged to a flight-test engineer on Stucky’s team named Brandon Parrish. Parrish called his girlfriend, Veronica McGowan, a fellow-engineer, up onto the stage with him and proposed. When she accepted, Stucky popped the cork on a champagne bottle, shook it up, and sprayed the couple. Afterward, one of Parrish’s colleagues said to him, “Way to set the bar too fucking high, bro.”

When the ceremony ended, Stucky, the pilots, and the mission-control team gathered back at the main hangar. The pilots toasted with paper cups of whiskey, and then went to Denny’s for lunch. Stucky and Agin split a hamburger, and the pilots showed one another the latest cockpit photos and read selected tweets aloud. Vice-President Mike Pence tweeted his congratulations: “the 1st crewed flight to launch from US soil in over 7 years!”

Stucky checked his watch and noted that they were due back at the hangar in fifteen minutes for more post-flight reviews. After all, SpaceShipTwo was being tested for regular and repeated missions, and not merely a one-off flight. There was flight data to plug into the models and run through the simulator, Stucky said. “You know, to see if there’s anything more we can learn.” Virgin Galactic could begin commercial service—flying customers to space—as early as late next year.