A look at what's involved in getting this billionaire and his civilian crew into space

For the first time in 60 years of human space flight, a rocket is poised to blast into orbit with no professional astronauts on board — only four tourists.

SpaceX's first private flight will be led by billionaire Jared Isaacman, 38, who's bankrolling the entire trip. He's taking two sweepstakes winners and a physician's assistant with him on the three-day, round-the-world trip. The four will ride together in a fully automated Dragon capsule — the same kind that SpaceX uses to send astronauts to and from the International Space Station for NASA. 

Set to launch Wednesday night from the Kennedy Space Center in Cape Canaveral, Fla., the two men and two women will soar 160 kilometres higher than the space station, aiming for an altitude of 575 kilometres, just above the current position of the Hubble Space Telescope.

Billionaire's quest

When Isaacman, the founder of payment-processing firm Shift4 Payments, announced the flight in February, he pledged $100 million US to St. Jude Children's Research Hospital and aims to raise another $100 million in donations. Isaacman is pictured earlier this year in front of the first stage of a Falcon 9 rocket at SpaceX in Hawthorne, Calif.

(Patrick T. Fallon/AFP/Getty Images)

Isaacman offered one of the four capsule seats to the hospital, which in turn offered it to physician assistant Hayley Arceneaux, pictured below on the right with her crew mates in Bozeman, Mont., during a "fighter jet training" weekend last month to familiarize them with G-forces. Now 29, Arceneaux was 10 when she was diagnosed with bone cancer and had much of her left thigh bone replaced with a titanium rod. She'll be the first person in space with a prosthesis, and has said she is proud to pave the way for "those who aren't physically perfect." 

(John Kraus/Inspiration4/The Associated Press)

It's been a whirlwind since all four crew members came together in March. They hiked up Washington state's Mount Rainier in the snow, sampled brief bursts of weightlessness aboard modified aircraft and took intense, rapid spins in fighter jets and centrifuges. The group is pictured below floating during a zero gravity flight out of Las Vegas. The plane, a modified Boeing 727, flies multiple parabolic arcs to provide 20-30 seconds of weightlessness.

(John Kraus/Inspiration4/The Associated Press)

Isaacman and SpaceX settled on three days as the sweet spot for orbiting the Earth. That gives him and his fellow passengers plenty of time to take in the views through a custom bubble-shaped window, take blood samples and conduct other medical research, and drum up interest for auction items to benefit the hospital. The four stand in the crew access arm they'll use to board the Falcon 9 at the Kennedy Space Center when it's time to launch.

(John Kraus/Inspiration4/The Associated Press)

Contest winners claimed the final two seats. Sian Proctor, 51, below left, a community college educator and former geology instructor, beat out 200 other Shift4 Payments clients with her space-themed artwork business. Also a pilot, she was a NASA astronaut finalist more than a decade ago. Chris Sembroski, 42, centre left, a data engineer and former Air Force missileman entered an open lottery by donating to St. Jude. He didn't win, but a college friend did and gave him the slot. Below, the four are pictured on July 2 at Duke Health in Durham, N.C., during hypoxia training to understand how each person reacts in a low-oxygen environment.

(John Kraus/Inspiration4/The Associated Press)