The first all-civilian mission to orbit is expected to launch this evening via a SpaceX Falcon 9 rocket. Jared Isaacman, founder and CEO of the payments processing company Shift4 Payments (FOUR), paid for the mission, called Inspiration4. 

Four people, none of whom are professional astronauts, will spend three days orbiting Earth on the Dragon spacecraft developed by Elon Musk's SpaceX. 

Besides going on the trip of a lifetime, the crew will have time to conduct experiments related to human physiology in microgravity.

"Space is a unique environment and there are opportunities to use the microgravity environment to find and develop new treatments and cures for various diseases and ailments," founder of Space Advisors and author of Space is Open for Business, Robert Jacobson told Yahoo Finance.

"Props to Elon Musk for being open to flying Inspiration4. His approval of this mission means that he is confident in the safety and reliability of the vehicle, his teams, and the rest of the necessary infrastructure," he added. 

The capsule will travel approximately 350 miles above Earth, orbiting higher than the International Space Station. 

Who's going

Isaacman, who is also an accomplished pilot, will be commanding the mission. He donated the other crew seats to raise money for St. Jude's Hospital. Each of the voyagers was selected differently. All went through commercial astronaut training in preparation for the mission. 

Hayley Arceneaux, a 29-year-old physicians' assistant at St. Jude's Hospital will be going. She is also a bone cancer survivor and had been treated at the facility when she was younger. Arceneaux will become the youngest American and the first person with a prosthesis to travel to space.

Dr. Sian Proctor is a 51-year-old geoscientist and STEM educator selected for the mission via an online contest. She will be the fourth Black woman in the United States to go to orbit.

The fourth seat was won via a raffle for St. Jude's Hospital. The winner gifted the seat to Christopher Sembroski, a 42-year-old Lockheed Martin (LMT) employee. 

How this launch differs from Jeff Bezos or Richard Branson's voyages

Isaacman is the third billionaire to pay for a space-related voyage this year, and the first to fund a private voyage to orbit on a SpaceX vehicle. 

Comparing this trip to Jeff Bezos' Blue Origin mission on July 20th, or Virgin Galactic (SPCE) founder Richard Branson's recent voyage is "apples to oranges," says Jacobson. 

"Sub-orbital flights, which is what Branson and Bezos have successfully completed is difficult, but not nearly as difficult as orbital flights" said Jacobson. 

Orbital flights "takes more technical complexity, more fuel, everything, recourses — It's a big deal," he added. 

Musk's SpaceX has been focused on orbital travel from the start, while Bezos' Blue Origin is working toward orbital voyages. Both have been around for almost the same amount of time.

'Eventually, it will be more of a regular occurrence'

Expect to see more missions like these in the future, says Robertson. Axiom Space has contracted SpaceX for several commercial missions. The first one is scheduled for later this year.

"Eventually, it will be more of a regular occurrence that private individuals and/or organizations will purchase seats or entire missions for these orbital and longer duration flights on vehicles that were designed, developed and manufactured by private businesses," added Jacobson.

Liftoff is expected to happen sometime on Wednesday night, no earlier than 8:02 p.m. EDT from NASA's Kennedy Space Center in Florida. Upon completion of the three-day journey, Dragon will reenter Earth’s atmosphere for a soft water landing off the coast of Florida.

Ines is a is a markets reporter covering stocks from the floor of the New York Stock Exchange. Follow her on Twitter at @ines_ferre