Update 10:50 AM: The livestream appeared to experience technical difficulties ahead of takeoff. The plane took off around 10:40 AM. Soon after, the stream started. Original story continues below.

Virgin Galactic will launch Richard Branson and three company employees to the edge of space on the morning of Sunday, July 11th. The company is promising quite a show for the mission: Stephen Colbert will host the mission’s livestream, singer-songwriter Khalid will reportedly perform a new single live onstage following the spaceplane’s landing, and Branson has said he’ll “announce something very exciting” after his spaceflight.

The flight marks one of the company’s final test missions before it aims to kick off commercial space tourism business next year. The mission, dubbed Unity 22, will mark Virgin Galactic’s fourth flight to space carrying humans, with its largest crew yet. Four people, including Branson, will test the astronaut cabin experience, and two pilots will be in the cockpit.

The action will start when Virgin Galactic’s twin-fuselage WhiteKnight carrier aircraft takes off from Spaceport America, the company’s spaceport in New Mexico on Sunday morning. The WhiteKnight aircraft, VMS Eve, will carry a rocket-powered spaceship called VSS Unity, with Branson and others on board. About 40 minutes after takeoff, Unity will drop from the middle of the mothership and ignite its rocket engine moments later to send Branson and the crew to the edge of space, about 55 miles high, for a few minutes of weightlessness. Unity will return to a landing strip at Spaceport America, much like any normal commercial airplane.

Early Sunday morning, Virgin Galactic delayed WhiteKnight’s takeoff by 90 minutes due to overnight weather over Spaceport America, pushing the new time to 10:30AM ET.

Unity 22 is a significant step forward for Virgin Galactic’s ambitions for space tourism, a burgeoning market catered to wealthy adventure-seekers. The company, started in 2004, has already sold roughly 600 tickets, with each ticket going for around $250,000. Branson is just one player in the billionaire-led race to court space tourists. He’s vying with Jeff Bezos’ Blue Origin, which aims to launch passengers on its suborbital New Shepard rocket, and Elon Musk’s SpaceX, which plans to put tourists in its orbital Crew Dragon capsule for a longer and more expensive experience in space.

Sunday’s mission has also been surrounded by an increasingly spicy air of competition with Bezos. Virgin Galactic announced Branson’s spaceflight a few weeks after Blue Origin announced it would send Bezos to space on July 20th. Then, Blue Origin announced it’d also fly Wally Funk on its July 20th mission, an aviator who initially planned to fly on Virgin Galactic’s spaceship first. Branson denies his new flight date was meant to beat Bezos to space; he told The Washington Post last week it was just a “wonderful coincidence that we’re going up in the same month.”

Watch Virgin Galactic’s livestream starting at 10:30AM ET on Sunday on its Twitter, Facebook, and YouTube.

Update Sunday, 6:00AM ET: Added update on Unity 22’s 90-minute weather delay