MOSCOW, March 19. /TASS/. Russian space corporation Roscosmos spokesman Vladimir Ustimenko has promised that Russian cosmonauts will go on a lunar mission "soon by space standards."

"It will happen soon, very soon by space standards, I should say," he told a news conference devoted to the beginning of a four-month isolation experiment SIRIUS on Tuesday.

Russian Academy of Sciences member Yuri Baturin said that experience gained in the process of the isolation experiments SIRIUS would be of great help in preparations for future lunar missions. The experiment is an imitation of an international mission to the Moon’s orbit and selection of a future lunar base.

The RAS Council for Space at the end of 2018 approved a lunar program concept but at the same time issued some recommendations for complementing it. Roscosmos said the program would be carried out in several stages extending up to 2040. Before, various concepts of deep space exploration programs had been proposed, including flights to the Moon. Some mentioned 2030 or 2031 as likely dates of the first manned flight to the Moon.

The project SIRIUS is being held by the Institute for Bio-Medical Problems under the Russian Academy of Sciences and the United States’ National Aeronautics and Space Administration NASA in cooperation with partners in Germany, France, Italy and other countries. It envisages a series of experiments to make preparations for deep space missions.

The first in the series of joint Russian-US experiments SIRIUS was held in November 2017. It lasted 17 days. Now four-month, eight-month and twelve-month long experiments are due.