CAPE CANAVERAL, Fla. — The four people on SpaceX's first private flight are fairly ordinary, down-to-Earth types brought together by chance.

They'll circle Earth for three days at an unusually high altitude — on their own without a professional escort — before splashing down off the Florida coast.

Meet the crew that's taking space tourism to new heights following Wednesday night's launch from NASA's Kennedy Space Center:

JARED ISAACMAN, SPONSOR

Isaacman struck it rich with the payment-processing business he started in his parents' basement after quitting high school. He later went to an aeronautical university, took to the skies in fighter jets and started Draken International to provide military-style training in tactical aircraft. Space beckoned, and the Easton, Pennsylvania, entrepreneur purchased an entire flight from SpaceX to circle the Earth. The 38-year-old considers flying in air shows, his other hobby, as way more dangerous. "I don't consider myself like a risk-taker or a thrill-seeker," says Isaacman, whose daughters are 7 and 5. "I try to seek out what I think are interesting challenges in life and, when I can, I tether it with a very worthwhile cause." This time it's St. Jude Children's Research Hospital. Isaacman has pledged $100 million to St. Jude and is seeking another $100 million in public donations. To drive home the message that space is for "just everyday people," Isaacman offered one of the four capsule seats to St. Jude and held sweepstakes for the other two.

HAYLEY ARCENEAUX, ST. JUDE'S REP

Now a physician assistant at St. Jude, Arceneaux was a bone cancer patient at the Memphis, Tennessee, hospital at age 10. To save her left leg, St. Jude replaced her knee and part of her thigh bone, implanting a titanium rod. She's the first person with a prosthesis in space and, at age 29, the youngest American. She was St. Jude's runaway choice in January as the hospital's representative in space. Arceneaux kept up with her fellow passengers in training, even while trudging up Washington's Mount Rainier in the snow. Her only compromise: SpaceX adjusted her capsule seat to relieve knee pain. "I'm so excited about opening space travel up to so many, so many different kinds of people and those that aren't physically perfect," Arceneaux says. She'll chat with St. Jude patients from orbit, reminding them that their dreams, too, can come true. She's taken along her late father's St. Jude tie, a prized possession. "I am so thankful for my journey with cancer because it gave me a love for life, just a zest for life and the confidence to say 'yes' to opportunities," she says. "This is the biggest honor of my life."

CHRIS SEMBROSKI, RAFFLE WINNER

Sembroski, an Air Force veteran and data engineer for Lockheed Martin in Everett, Washington, always saw himself as the space booster behind the scenes, helping to educate the public. He shot off model rockets in college and worked as a Space Camp counselor. So he considered it a "crazy fantasy" when he saw the Super Bowl ad in February announcing the space seat raffle and made a donation to enter. He didn't win but a college friend did, and he offered Sembroski his spot on the flight. Sembroski says he was more subdued than others when he found out: "Just no words were coming out. Since then, I've gotten a lot more enthusiastic." After six months of training, Sembroski, 42, has "no worries, no concerns, maybe a little bit of stage fright" about singing and playing a ukulele in orbit that will be auctioned off to support St. Jude. His schoolteacher wife, Erin, is "more than anxious about it for the two of us." They have two daughters, ages 3 and 9. Sembroski says he'll reflect on the historic nature of the flight — and his role in it — once he's back on Earth.

SIAN PROCTOR, BUSINESS WINNER

Proctor applied to NASA three times to become an astronaut. The 51-year-old geologist and community college professor from Tempe, Arizona, actually made it to the finals more than a decade ago. After striking out with NASA, she set her sights on private spaceflight. But as 2021 loomed, she thought she'd aged out — until she learned of Isaacman's space sweepstakes for his clients. She'd begun creating space-themed artwork when the coronavirus pandemic struck and turned to Isaacman's Shift4 company to sell her paintings. When asked on the eve of launch if she was nervous, she said her only worry was that "this moment would never come in my life." As only the fourth Black woman in space after three NASA astronauts, Proctor hopes to inspire other minority women. "As we move to the moon and Mars and beyond, we're writing the narrative of human spaceflight right now" by focusing on diversity, Proctor says. "We're on Starship Earth and we want to bring everybody along with us." She caught the space bug early: Her late father worked at NASA's tracking station in Guam during the Apollo moon landings.