"Only one version of the super-heavy class rocket is being considered now. It has been proposed by the Samara-based Progress rocket space center and comprises six side boosters with RD-171MB engines and a central core stage powered by an RD-180 engine. Other proposed projects are no longer under consideration", the source said.
According to the source, the discussion is now focused on the choice of the launch scheme. In the first scheme, the RD-180 engine fires in the first seconds of the flight and then lowers its thrust to 30 percent of the nominal. In the second scheme, the RD-180 engine starts some time after the launch of the rocket.
"Both schemes are designed to save fuel in the central core stage, but the first scheme is considered preferable", the source added.
In November 2019, the conceptual design of the rocket should be completed. The first launch of the rocket is scheduled for 2028, while the carrier itself should be made in 2027.
The era of lunar exploration with the use of space technology began on 2 January 1959, when the Soviet Union launched the Luna-1 automatic interplanetary station, the first-ever spacecraft sent toward the Moon.