The launch next monthof the first all-civilian mission to orbit is an ambitious test for a burgeoning space industry's futuristic dream of sending many more ordinary people to space in the next few years.

Why it matters: Companies and nations envision millions of people living and working in space without having to become professional, government-backed astronauts. Those hopes are riding on SpaceX's next crewed mission, called Inspiration4.

• Previous launches have taken billionaires to suborbital space or sent space tourists to the International Space Station alongside professional astronauts, but this mission is the first with a crew made up entirely of amateur astronauts.

What's happening: Inspiration4 is effectively a proof of concept for the idea that an all-civilian mission aboard SpaceX's Crew Dragon spacecraft — and ostensibly that all-amateur spaceflight — can work.

• Four crewmembers — Jared Isaacman, Sian Proctor, Chris Sembroski and Hayley Arceneaux — will launch atop a Falcon 9 rocket from Cape Canaveral, Florida, on Sept. 15.
• They will orbit the Earth for about three days, flying higher than the International Space Station and Hubble Space Telescope before coming in for a splashdown off the Florida coast.
• During their mission, the crew will live in close quarters, stare down at Earth and at the stars, perform science experiments and keep an eye on how their spacecraft is performing while mission controllers monitor it from the ground.

The big picture: SpaceX wants space travel one day to be akin to air travel so thatanyone who wants to can fly to orbit or far-off parts of space.

• "We'd like to see aircraft like — airline, like — operations from a human spaceflight perspective, and so this chance to have our first commercial all-civilian flight is awesome," SpaceX director of human spaceflight Benji Reed told me.

Yes, but: Flying to space isn't anything like flying on a commercial airliner, at least not yet.

• It's taken this crew months of training in locations around the U.S. to get ready for their launch, and it has dominated their lives since the full crew was announced in March.
• The four crewmembers have effectively gotten a crash course in astronaut training, spending time in simulators, studying reams of notes on their own time and taking quizzes from SpaceX.
• While they may not be professionals, they will certainly not be like a typical airline passenger when they fly to space in September. Their training has effectively been a test of how much pre-flight instruction ordinary people will need to fly to orbit and how quickly that process can go.

How it works: Inspiration4's crew was chosen through means more akin to something on reality TV than professional astronaut selection.

• Isaacman wanted the mission to be all-civilian from the start and he didn't want to just take a few of his friends along for the ride.
• Instead, he decided to add a fundraising component — raising $100 million for St. Jude Children's Research Hospital on top of Isaacman's $100 million donation — and open up seats to complete strangers.
• Sembroski was chosen via a sweepstakes that anyone could enter. Proctor won her seat through a contest for entrepreneurs. Arceneaux — a childhood cancer survivor treated by St. Jude who is now a physician assistant at the hospital — was picked by the charity to represent it in space.

The bottom line: Inspiration4 is a coming-of-age moment for an adolescent commercial spaceflight industry trying to fly many more people to space in the future.

Go deeper: Listen to the first episode of the new season of Axios' How it Happened: The Next Astronauts here.