A white and silver space plane rocketed toward the edge of Earth’s atmosphere, more than 46,000 feet above the stark New Mexico desert, propelled by a fiery plume of burning laughing gas and solid rubber fuel.

A few minutes later, the craft’s two pilots and four passengers, including billionaire Richard Branson, were floating more than 53 miles above our planet’s surface: high enough to see Earth’s curvature and, for a few minutes at least, to escape gravity.

The gleaming craft, Virgin Galactic’s V.S.S. Unity, took off mid-air from a larger carrier aircraft and flew more than 53 miles into the sky. As it ascended, it rotated its twin tail booms, reconfiguring the vehicle to fall through the upper atmosphere like a badminton shuttlecock. V.S.S. Unity glided down to a landing strip in New Mexico and rolled to a stop fifteen minutes after separating from the mothership.

The Unity 22 mission is the largest crew that Branson’s company, Virgin Galactic, has ever flown to the edge of space. The spectacle was also a highly visible milestone in the push to commercialize access to suborbital space for both pleasure and profit. Virgin Galactic’s fourth spaceflight with humans aboard—comes just nine days before billionaire Jeff Bezos is slated to fly on New Shepard, a suborbital rocket built by his company Blue Origin.

Both companies have been chastised for being vanity projects and luxuries for the ultra-rich. Virgin Galactic had been charging $250,000 per ticket in advance sales, but has since announced that the price will be raised. Blue Origin has yet to begin selling seats on New Shepard or release ticket prices, but a seat on the upcoming flight with Bezos sold for $28 million in a June auction.

Aside from the rich’s glory-seeking exploits, new space vehicles such as SpaceShipTwo and New Shepard could provide a unique platform for aerospace and scientific research.

Private space missions are nothing new. Since 2000, a number of wealthy tourists have spent tens of millions of dollars to travel to the International Space Station. Furthermore, NASA has gradually encouraged private companies to take over U.S. cargo and astronaut launches to the ISS. NASA began commercial cargo flights in 2012, and commercial crew flights will begin in 2020.

Because the spacecraft does not have to trudge through the dense lower atmosphere under its own power, it can carry less fuel when launched from mid-air. Furthermore, by using a space plane, the vehicle can take off and land on a long conventional runway, eliminating the need for additional launchpad infrastructure. With the announcement of the Ansari X Prize in 1996, design work on SpaceShipOne, the experimental predecessor to SpaceShipTwo, began. That competition offered a $10 million prize to the first fully private team to fly a spacecraft more than 100 kilometers above the Earth’s surface twice in two weeks by the end of 2004, all while carrying a pilot and two passengers.

Burt Rutan, an iconoclastic engineer known for his quirky, extremely efficient airplane designs, was an early favorite in the competition. Rutan chose an air-launch design with a novel approach to descent for his X Prize entry. Just before reaching its maximum altitude, SpaceShipOne’s two tail booms would hinge upward by 65 degrees, like hackles on a dog’s back. This “feathering” system significantly increased the craft’s drag during descent, allowing it to safely fall through the atmosphere, retract the tail booms, and glide to a runway for landing.

Virgin Galactic completed its third flight above 50 miles in May 2021, prompting the US Federal Aviation Administration to grant the company a full commercial license. The test paved the way for today’s launch of Unity 22—and gave the company enough confidence in the system to allow Branson to board.