The recycled SpaceX rocket blasted off from NASA's Kennedy Space Center in Florida just after 8 PM local time on Wednesday.
It's the first all-civilian crew ever to go into space and is different from the previous space trips made by billionaires in July flying higher and longer around the planet.
The venture was bought by 38-year-old billionaire Jared Isaacman, who made his fortune from a payment-processing company he started in his teens.
He gifted the three remaining seats to people with inspirational stories.
"You know, it is the first time that a global superpower hasn't sent people up into the orbital space, and I think that should send a message of all the things to come right."
The lucky three out of the 70-thousand people who applied include 29-year-old Hayley Arceneux, a childhood cancer survivor who works for St. Jude Children's Research Hospital, Chris Sembroski, a 42-year-old U.S. Air Force veteran who made a donation to St. Jude, and 51-year-old Sian Proctor, a geologist and community college teacher.
The Inspiration4 crew went through six months of rigorous training with SpaceX but the onboard computer systems will be in control throughout the three-day trip and will be monitored by SpaceX teams on the ground.
The passengers will spend three days orbiting the planet at 160 kilometers higher than the International Space Station - before splashing down off the coast of Florida this weekend.
The trip is packed with various activities and experiments.
Hayley Arceneux is expected to talk with her patients at St. Jude using NASA's communications system while Sian Proctor, who won her seat by being an artist, will paint.
The trip is another milestone in the space tourism market, entering a new era after a decade's hiatus with other billionaires such as Virgin Galactic's Richard Branson and Blue Origin's Jeff Bezos having made their own space trips earlier this year.
Kim Cheong-ah, Arirang News.