The richest man in the world is counting down the minutes to his spacefaring debut. Sixteen years after he set out in earnest to commercialize space travel, Jeff Bezos’ rocket company, Blue Origin, is scheduled to take its biggest step yet in that direction, with its founder along for the ride.

Bezos, the founder of Amazon.com and owner of the Washington Post, will be aboard the launch vehicle New Shepard along with three other passengers for its first crewed flight Tuesday morning. The flight was set to take off from a launch pad near Van Horn, Texas, at 6 a.m. Pacific time with a livestream starting at 4:30 a.m. There was a brief 15-minute hold in the countdown as the timelines got aligned, but it was lifted a few minutes before 6 a.m. The launch was delayed by about 11 minutes.

Aboard the New Shepard, in addition to Bezos, 57, will be Mark Bezos, the billionaire's 53-year-old brother; aviation pioneer Wally Funk, 82; and Oliver Daemen, 18. Funk and Daemen will become the oldest and youngest individuals to travel to space.

The four will experience just an 11-minute trip to suborbital space, with the vessel's autonomous flight systems in control of the journey.

Daemen is the first paying customer in what Blue Origin says will be the start of commercial service. Originally, a ticket was auctioned and sold for $28 million, but the ticket holder postponed their trip, citing scheduling conflicts, according to Blue Origin. The company did not release the name of the ticket holder or how much Daemen, the son of a Dutch private equity executive, paid for his spot.

“This marks the beginning of commercial operations for New Shepard, and Oliver represents a new generation of people who will help us build a road to space,” Bob Smith, chief executive of Blue Origin, said in a news release Thursday.

Blue Origin’s mission follows a successful launch this month by Virgin Galactic, a rival in the suborbital space tourism race.

Virgin Galactic's Unity spaceplane carried six people — including billionaire Richard Branson, the company's founder — to suborbital space for a few minutes of weightlessness before returning to Earth. The mission was intended to increase potential buyer’s confidence in the experience.

Bezos took to Instagram and congratulated Branson, adding, “Can’t wait to join the club!”

Blue Origin plans to launch tourists past the so-called Karman line 62 miles (100 kilometers) above Earth, which is often defined as the threshold of space, although NASA and the U.S. military set the line at 50 miles up.