Amazon founder Jeff Bezos will be aboard his own rocketship when it makes its first human voyage into space next month.

Blue Origin, Bezos’ space flight company, announced Monday morning that the billionaire and his brother, Mark, will be two of the six passengers on the New Shepard on July 20 — 15 days after Bezos steps down as Amazon’s CEO.

“Ever since I was five years old, I’ve dreamed of traveling to space,” Bezos wrote in an Instagram post. “On July 20th, I will take that journey with my brother. The greatest adventure, with my best friend.”

Bezos also posted a video showing him surprise his brother with the invitation.

“I wasn't even expecting him to say that he was going to be on the first flight,” Mark Bezos says in the video. “And then when he asked me to go along, I was just awestruck. ... What a remarkable opportunity not only to have this adventure, but to be able to do it with my best friend.”

Blue Origin is auctioning off one of the six seats. As of Monday, the highest bid stood at $2.8 million. The bidding will conclude with a live auction June 12.

The money from the winning bid will be donated to Club for the Future, Blue Origin’s foundation that aims to inspire future generations to pursue careers in science, technology, engineering or mathematics, and to help invent the future of life of space. 

Launching from Van Horn, Texas, the New Shepard will take the 11-minute flight just beyond the Kármán Line, the internationally recognized boundary of space about 65 miles above sea level. Passengers will then be able to unbuckle and float weightlessly about the spacecraft for three minutes before it begins its parachute-cushioned descent to the West Texas desert. 

The New Shepard is fully autonomous — there are no pilots. The rocket has flown 15 successful consecutive unnamed missions.