Washington (AFP)

Several hundred of them already have their tickets and have trained for a spectacular journey: a few minutes or a few days in zero gravity, in space.

These rich or very lucky passengers, complete novices, are preparing to embark on one of the many private missions about to be launched.

Sixty years after a man crossed this final frontier for the first time, the advent of space tourism, the first step towards the general public, is near.

Two companies, Virgin Galactic and Blue Origin, are currently developing vessels capable of sending private customers for a few minutes just over the border of space - a so-called suborbital flight.

"The oldest person I trained was 88 years old," Glenn King, director of the space training program at Nastar Center, a private company partnering with major players in the sector, told AFP.

Nearly 400 future Virgin Galactic passengers, many of them "businessmen or women", have already trained in the premises in Pennsylvania, United States.

The training program lasts only two days: a morning of theoretical lessons, then several simulations in a human centrifuge.

A rapidly rotating arm nearly 8 meters long reproduces the g-force corresponding to the vessel in which the client will be flying.

A medical team is on site.

This is possible because the clients "are just passengers", who don't have much to do other than "relax" and "take in the view".

The program's success rate is "99.9%," he says.

It is above all a matter of reassuring them by showing them that they can withstand the acceleration - for the modest sum of 4,000 to 10,000 dollars, depending on the preparation needs.

- A barrier: the price -

The biggest barrier to "space for all" is price.

For Virgin Galactic, the company of British billionaire Richard Branson, some 600 people have already bought a ticket.

Cost: $ 200,000 to $ 250,000.

Thousands of people are on the waiting list.

The start of operations is scheduled for "early 2022", and the company ultimately plans 400 flights per year.

Blue Origin has not yet communicated a price or schedule.

Money aside, will everyone be able to participate, or are health issues eliminating?

"You don't have to be in perfect health today to be able to go to space," says Glenn King, who says he has trained people with prostheses, diabetes, bone implants ...

The US agency overseeing aviation, the FAA, recommended in 2006 that future "commercial passengers" of suborbital flights complete "a simple questionnaire", relating to medical history, but also mental health.

On the other hand, the questionnaire is more detailed and coupled with examinations (blood test, radio, urine analyzes ...) for private orbital flights, going much further, for longer.

- To the moon -

Such missions, the cost of which this time count in the millions, are they planned by the company of billionaire Elon Musk, SpaceX, which has no less than four planned from this year.

In September, "Inspiration4" will be the first in the world to send only civilians into space, without a professional astronaut.

American billionaire Jared Isaacman has chartered a Falcon 9 rocket at his own expense, and is taking three passengers, for three days.

Then in January 2022, the company Axiom Space plans to send a former astronaut and three novices aboard the International Space Station.

The company eventually plans to fly to the ISS every six months, she told AFP.

Seven tourists have already visited the Station, between 2001 and 2009. A company had served as their intermediary: Space Adventures, which also made an agreement with SpaceX to send four clients into orbit around the Earth for several days, can -be in 2022.

Finally, in theory in 2023, the Japanese billionaire Yusaku Maezawa has booked him a flight aboard another SpaceX rocket under development, to go around the moon, with eight lucky ones being selected.

So when will the advent of mass space tourism?

Hard to say, according to industry expert Robert Goehlich of Embry-Riddle Aeronautical University.

"A new investor could speed up the schedule", or an accident, on the contrary, delay it.

But three factors must be combined: safety, profitability, and ... respect for the environment.

This last fact "will take a dominant role" in the coming years, he predicts.

© 2021 AFP