The Ax-1 crew (left to right): Axiom-1 astronauts Mark Pathy, Larry Connor, Michael López-Alegría, Eytan Stibbe (Credit: SpaceX)

On April 9, 2022, four civilians made history as the first all-private "astronaut" team to reach the International Space Station (ISS). Former NASA astronaut Michael López-Alegría and three first-time fliers, Mark Pathy, Larry Connor, and Eytan Stibbe — who each paid $55 million for the trip — will spend eight days on the orbiting science laboratory. They are scheduled to return to Earth aboard SpaceX's Crew Dragon capsule on April 19, 2022.

The groundbreaking mission, dubbed Ax-1, was organized by Houston, Texas-based Axiom Space, in partnership with SpaceX and NASA. While the journey is being touted as a milestone in the commercialization of spaceflight, the company maintains that the four men should not be called "space tourists."

Derek Hassmann, operations director for Axiom Space, explains, "The distinction is that our guys aren't going up there and floating around for eight days taking pictures and looking out of the cupola. I mean we have a very intensive and research-oriented timeline plan for them."

The Ax-1 mission team will wear the Brain.sparce headset to map how the brain changes during spaceflight (Credit: Brain.space)

The company says that each crew member had to go through hundreds of hours of astronaut training with both NASA and SpaceX before the flight. Moreover, the private astronauts will conduct 25 different experiments, encompassing over 100 hours of research at the ISS. They include projects for the Mayo Clinic and the Montreal Children's Hospital.

The Ax-1 crew will also help researchers determine the impact of microgravity on brain health. The data, recorded by a special headset developed by Israeli- based startup Brain.space, will be made available to all scientists.

"Every organ is being measured in space — body mass, temperature, heart rates — everything is being measured, except for this organ," Yair Levy, co-founder and CEO of Brain.space, told Cnet.com. "We're going to see if we can identify whether the brain adapts to a new homeostasis in space."

Axiom Space's commercial space operations will continue with a second mission to the ISS in 2023. The Ax-2 mission will be led by former NASA astronaut Peggy Whitson. The ISS trips are just the start of the company's primary purpose — building the world's first private space station to replace the ISS, which is scheduled to be retired sometime after 2030.

Resources: Axiom Space, NASA.gov, theguardian.com, nbcnews.com