Blue Origin raised $28 million by auctioning a seat to accompany founder Jeff Bezos on a July 20 rocket ride –- the first time the company will carry people to space.

The identity of the winner won’t be revealed for a few weeks, Blue Origin said Saturday. The day’s live auction followed weeks of online bidding with more than 7,000 submissions from people in 159 countries. Bezos’s brother, Mark, will also make the trip.

The 11-minute excursion from Van Horn, Texas, will carry as many as six passengers. Blue Origin hasn’t yet revealed who else will be aboard the New Shepard spacecraft. The automated flight will be the company’s 16th but first with humans aboard.

Blue Origin is vying with Elon Musk’s Space Exploration Technologies and Richard Branson-backed Virgin Galactic Holdings Inc. to offer trips to space to a small number of wealthy tourists. Bezos has compared space tourism to the barnstormers whose stunt flying helped fuel public fascination in the early days of aviation and made planes a common mode of transportation.

Passengers aboard New Shepard, named for pioneering astronaut Alan Shepard, must be:

Between 5 feet (1.52 meters) and 6 feet, 4 inches tall, weighing 110 pounds-223 pounds (50-100 kilograms).

Able to climb the seven flights on the launch tower in less than 90 seconds and sit strapped in the vehicle for as long as 90 minutes without access to a lavatory.

Able to withstand gravitational forces of as much as 5.5 times the person’s normal weight during descent and 3 times the weight for as long as two minutes on ascent.

Passengers were advised to consult a medical professional about medical conditions and their ability to fly on New Shepard. Customers also must provide informed consent, acknowledging the various risks of flying to space.

SpaceX already ferries astronauts to the International Space Station for the National Aeronautics and Space Administration. Both SpaceX and Virgin Galactic are preparing to fly nongovernment customers.

Blue Origin will donate the auction proceeds to its Club for the Future foundation, which aims to inspire young people to pursue careers in science, technology and mathematics.

Bezos, who spends about $1 billion a year to fund Blue Origin, has been slowly selling off his stake in Amazon.com Inc. to invest in his space endeavors. He will step down as chief executive officer of Amazon on July 5, with Andy Jassy assuming the role.

This article was provided by Bloomberg News.