Kennedy Space Center (United States) (AFP)

Can four humans who have never been in space before spend three days alone orbiting the Earth, having only trained for a few months?

This is the challenge for SpaceX, whose first space tourism mission is to take off on Wednesday evening.

Called Inspiration4, it is the first in history to send only novices into orbit, without any professional astronaut on board.

Take-off is scheduled to take place from 8:02 p.m. (12:02 a.m. GMT Thursday), with a five-hour launch window and favorable weather for the moment.

The Falcon 9 rocket, carrying the Dragon capsule at its top, will be propelled from the legendary launch pad 39A at NASA's Kennedy Center in Florida, from where the Apollo 11 mission took off for the Moon.

The four Americans on board must travel beyond the International Space Station (ISS), to a target orbit of 575 km.

Each day they will circumnavigate the globe about 15 times.

At the end of their journey, they will begin a dizzying descent to land off Florida, slowed down by huge parachutes.

The mission was chartered by billionaire Jared Isaacman, 38, a financial services company boss and seasoned pilot.

The price he paid SpaceX has not been disclosed, but runs into tens of millions of dollars.

He will be the captain on board, and offered three more seats to strangers.

SpaceX Gal ROMA AFP mission crew

Hayley Arceneaux, a pediatric cancer survivor, is a 29-year-old medical assistant.

She will be the youngest American to go into orbit and the first person with a prosthesis (femur).

Chris Sembroski, 42, is a former US Air Force employee who now works in the aviation industry.

Finally, Sian Proctor, a 51-year-old professor of Earth sciences, had almost been selected in 2009 to become an astronaut for NASA.

She will be only the fourth African American woman to go to space.

- Physical tests -

The stated goal: to represent a turning point in the democratization of space, by proving that the cosmos is also accessible to people who have not been handpicked, and trained for many years as astronauts.

For SpaceX, this is nothing less than a first step towards a multiplanetary humanity - Elon Musk's ultimate vision.

"We realize how lucky we are, and we try to be very thoughtful in our approach, in order to hopefully set the standard for the missions to follow," Jared Isaacman said at a conference on Tuesday. Press.

"It is just beginning."

The four members of SpaceX's Inspiration4 mission, Jared Isaacman, Chris Sembroski, Sian Proctor and Hayley Arceneaux (left to right), in Florida in March 2021 John Kraus Inspiration4 / AFP

On board, their biological data (heart rate, sleep, etc.) as well as their cognitive capacities will be analyzed.

They will also undergo tests before and after the trip, to measure the effect on their bodies.

Their training only lasted about six months.

The flight should normally remain fully automated, but the crew has been trained by SpaceX to be able to take control in the event of an emergency.

They were also physically tested.

Together, they trekked in the snow up to over 3,000 meters in altitude in the American Northwest, and experienced the g-force to which they will be exposed thanks to a centrifuge (long arm in rapid rotation) and jet flights.

The mission also serves as a huge fundraiser for the pediatric hospital of St Jude (Memphis, Tennessee), where Hayley Arceneaux now works after being treated there as a child.

In the vessel will be various objects (a ukulele, 30 kg of hops intended to make space-flavored beer on Earth, digitally certified NFT works, etc.) which will then be auctioned.

- Boiling sector -

This mission concludes a summer marked by the flight of billionaires over the last frontier: first Richard Branson on July 11, aboard the Virgin Galactic ship, then a few days later Jeff Bezos, with his company Blue Origin.

But these flights only offered a few minutes in zero gravity.

This is the fourth time that the company of Elon Musk, which in just a few years has become a giant in the sector, has sent humans into space, after having transported 10 astronauts to the ISS on behalf of NASA.

There have already been tourists in space: wealthy personalities, for example, visited the ISS between 2001 and 2009, aboard Russian rockets.

Space X's first space tourism mission, which is due to take off on Wednesday evening, is the first in history to send only novices into orbit Patrick T. FALLON AFP / Archives

But the advent of private enterprise programs today marks a turning point.

SpaceX subsequently plans other space tourism flights, including one from January 2022, which will notably transport three businessmen to the ISS.

© 2021 AFP