They must replace the crew that has just left the ISS, which included the French Thomas Pesquet, returned to Earth overnight from Monday to Tuesday.

They will be launched from Florida by a SpaceX Falcon 9 rocket on Wednesday evening at 9:03 p.m. local time (02:03 GMT Thursday).

Their Dragon capsule must then dock at the station Thursday at 7:10 p.m. (00:10 GMT Friday).

NASA astronauts Raja Chari, Kayla Barron and Tom Marshburn, as well as European Space Agency (ESA) astronaut Matthias Maurer, have been in quarantine for days at the Kennedy Space Center.

They were initially due to leave at the end of October but the takeoff was delayed several times, in particular because of the weather, then of a "minor health problem" with one of the astronauts - on which Nasa did not provide more. details.

The space agency therefore decided to bring the crew of Crew-2, including Thomas Pesquet, back to Earth before launching Crew-3.

The handover period between the two crews, which normally takes place in zero gravity for a few days, was therefore unable to take place.

The mission is called Crew-3 because it is the third operational to the ISS provided by SpaceX on behalf of NASA.

The Crew-3 mission to the AFP International Space Station

But this is actually the fifth time that Elon Musk's company has launched humans into orbit: before Crew-1 and Crew-2, a test mission (Demo-2) had sent two astronauts to the ISS. .

And in September, SpaceX also launched four tourists for three days in space, independent of NASA.

Reception of tourists

The crew of Crew-3 will embark on Wednesday in a brand new Dragon capsule, the example of which has been dubbed "Endurance".

For American Tom Marshburn, this will be the third time in space.

He already flew aboard a space shuttle in 2009, then a Soyuz rocket in 2012-2013.

The other three astronauts, however, will make the trip for the first time.

Matthias Maurer will be the twelfth German to end up in orbit.

Their mission will include many experiences.

One of them aims to observe the effects of the diet on the intestinal flora and the immune system of astronauts, their defenses being often weakened by a prolonged stay in space.

They will thus have the opportunity to consume a larger selection of freeze-dried fruits and vegetables (squash, kale ...) as well as barramundi, a fish.

The crew of Crew-3 (from left to right), German astronauts Matthias Maurer, and Americans Tom Marshburn, Raja Chari and Kayla Barron Joel KOWSKY NASA / AFP

Crew-3 astronauts will also carry out spacewalks, in particular to continue installing new solar panels on the ISS.

And they will host two tourist missions: Japanese people brought in by a Russian Soyuz spacecraft at the end of the year, then in February 2022 passengers from the Ax-1 mission, organized by the company Axiom Space in partnership with SpaceX.

© 2021 AFP