CAPE CANAVERAL, Fla. (AP) SpaceXs first private flight blasted off Wednesday night with two contest winners, a health care worker and their rich sponsor, the most ambitious leap yet in space tourism.

It was the first time a rocket streaked toward orbit with an all-amateur crew no professional astronauts.

The Dragon capsules two men and two women are looking to spend three days circling the world from an unusually high orbit 100 miles (160 kilometers) higher than the International Space Station before splashing down off the Florida coast this weekend.

Leading the flight is Jared Isaacman, 38, who made his fortune with a payment-processing company he started in his teens.

Its SpaceX founder Elon Musks first entry in the competition for space tourism dollars. Isaacman is the third billionaire to launch this summer, following the brief space-skimming flights by Virgin Galactics Richard Branson and Blue Origins Jeff Bezos in July.

Joining Isaacman on the trip dubbed Inspiration4 is Hayley Arceneaux, 29, a childhood cancer survivor who works as a physician assistant where she was treated St. Jude Childrens Research Hospital in Memphis, Tennessee. Isaacman has pledged $100 million out of his own pocket to the hospital and is seeking another $100 million in donations.

Also along for the ride: sweepstakes winners Chris Sembroski, 42, a data engineer in Everett, Washington, and Sian Proctor, 51, a community college educator in Tempe, Arizona.

Arceneaux is set to become the youngest American in space and the first person in space with a prosthesis, a titanium rod in her left leg.