Amazon founder Jeff Bezos will fly to space today (Tuesday 20 July).
The 57-year-old will be launched from Texas, United States, to the edge of space in a 10-minute flight on board his Blue Origin New Shepard rocket.
A live broadcast is due to kick-off at 6.30am CDT, with lift-off targeted for 8.00am CDT (2pm in the UK).
The billionaire will become the second person to ride his own rocket into space, following Virgin Galactic's Sir Richard Branson by nine days.
On Instagram, Bezos - who recently stepped down as Amazon CEO - said he 'can't wait' for the excursion.
Joining Bezos on the flight will be his brother Mark and Wally Funk - one of 13 female pilots who went through the same tests as Nasa's Mercury 7 astronauts in the early 1960s but never made it into space because only men were allowed - and Oliver Daemen.
The latter is an 18-year-old physics student who has taken the place of a $28 million auction winner who is now too busy to make the trip.
Oliver bagged his seat on board the flight as his dad was one of the runners-up in the auction.
How much he paid for the ticket has not been disclosed, but a family spokesperson said it was considerably less than the winning bid.
His father, Dutch financier Joes Daemen, founded private equity firm Somerset Capital Partners.
Joes paid for the ticket, but decided to let his son go instead.
Oliver said: "I am super excited to go to space.
"I've been dreaming about this all my life and I will become the youngest astronaut ever because I'm 18 years old.
"I am super excited to experience zero G."
He added: "This is so unbelievably cool!
"The flight to and into space only takes 10 minutes, but I already know that these will be the most special 10 minutes of my life."
Featured Image Credit: Instagram/Jeff Bezos
You can watch the launch here.