Washington (AFP)

Russia is unlikely to participate in the future Moon-orbiting station that the United States plans to assemble from 2023, the two countries appearing to mark the end of two decades of exceptional cooperation on the International Space Station ( ISS).

The head of the Russian space agency Roskosmos, Dmitry Rogozin, stressed that the ISS, built by the two nations and continuously occupied by Russians and Americans since 2000, was "really an international project", during the 71st Congress international astronautics which opened virtually on Monday.

Europe, Canada and Japan also participate in the ISS.

The ISS has in fact resisted the deterioration of relations between Moscow and Washington: Roskosmos and Nasa operate the station hand in hand, and American astronauts have been going there since 2011 aboard Russian rockets, proud to continue their cooperation far from land geopolitical disputes.

But the ISS is nearing the end of its life, by 2030, and NASA has unilaterally launched its lunar program, without prior consultation with its historical partners.

"From our point of view, the Lunar Gateway in its current form is too American-centric," Dmitry Rogozin said, according to comments translated live by an interpreter.

He then confirmed that it was "likely" that Russia "will not participate on a large scale".

The Gateway was announced under President Donald Trump and aims to assist the return of American astronauts to lunar soil from 2024, for the first time since 1972, a program dubbed Artemis.

Initially reduced to a single housing module, the station is supposed to grow over the years, without ever having to reach the size of the ISS.

NASA maintains that the project has an international vocation, and is eagerly seeking to involve other space agencies.

Canada, Japan and Italy have signed cooperation agreements with Artemis.

The boss of Roskosmos, however, stressed that he did not rule out that Russian aircraft one day moor at the station, which will imply a harmonization of mooring standards, as for the ISS.

"The trip to the moon presents high risks," said Dmitry Rogozin.

"That is why we will need at least two transport systems."

© 2020 AFP