Japanese billionaire Yusaku Maezawa, 46, who made his fortune in online fashion, and his assistant Yozo Hirano took off from the Russian cosmodrome in Baikonur, Kazakhstan, last week. The flight in the space capsule lasted six hours, before docking in the Russian segment of the ISS.
The space tourists' stay in the orbital station will be documented by Yozo Hirano and his boss on YouTube. Cosmonaut Alexander Missurkin has planned a "friendly" badminton tournament in zero gravity with his companions.
The billionaire has set himself 100 tasks to accomplish in space. Before that and for many weeks, he and his assistant prepared at Star City, a city built near Moscow in the 1960s to train generations of cosmonauts.
The previous trip to space by a Japanese tourist was in 1990 when a journalist stayed on board the Soviet Mir station.
The lucrative private space tourism sector is currently being boosted by the recent entry into the race of the companies of US billionaires Elon Musk (SpaceX) and Jeff Bezos (Blue Origin), as well as that of Britain's Richard Branson (Virgin Galactic).
In September, SpaceX organized a three-day flight into orbit with an all-amateur crew. It also plans to take several space tourists around the moon in 2023, including Mr. Maezawa, who is funding the operation.
After a decade-long hiatus, the flight marks the return of Russia's space agency, Roscosmos, to the arena at a time when Russia's aerospace industry is plagued by corruption scandals and technical and financial difficulties.
In 2020, with the launch of SpaceX's rockets and capsules, this country lost its monopoly on manned flights to the ISS and the tens of millions of euros that NASA and other space agencies paid for each seat onboard the Soyuz.
Eight Flights Between 2001 and 2009
The mission of the two Japanese space tourists is organized by Roscosmos and its American partner Space Adventures. Between 2001 and 2009, these two groups had already sent wealthy entrepreneurs into space eight times.
"It's great [...] to share this great adventure with Mr. Maezawa,” said Tom Shelley, the president of Space Adventures, who was present at Baikonur, shortly after the takeoff.
As a sign of the Russian space sector's willingness to make a fresh start, Roscosmos also sent a movie director and an actress to the ISS in October to shoot the first-ever feature film in orbit, ahead of a competing project by Hollywood star Tom Cruise.