"Union" - to the Moon! How do you like that, Elon Musk?
On January 10, TASS was authorized to announce: The US National Aeronautics and Space Agency (NASA) has officially asked Roscosmos to develop a version of the Soyuz spacecraft for flights to the Moon.
As Dmitry Rogozin, general director of the Roscosmos state corporation, said in an interview with the federal TV channel Rossiya-24, “the Americans are asking to develop a version of the Soyuz capable of reaching the Moon and back, in order to create a second backup transport system.”

Rogozin also noted that NASA insists that Russia continues to deliver American astronauts to the ISS using Soyuz spacecraft.
Thus, the letters of intent signed in 2017 between Roscosmos and NASA, indicating the lunar ambitions of the two countries, seem to be beginning to take shape, despite the sharp cooling in politics.
Why Soyuz, why not Elon Musk?
The answer lies in the history of the creation and operating experience of the Soyuz spacecraft. They were created more than 50 years ago specifically for the lunar program of the USSR, but after the victory of the Americans in the lunar race, the Soyuz began to be used in the orbital flight program, achieving perfection in simplicity, reliability and manufacturability.
Currently at the development stage are promising multi-purpose manned spacecraft "Federation" (Russia), Orion, Dragon V2 and CST-100 (USA), intended both for orbital flights and for flights to the Moon and even Mars (Orion). Unlike the Federation, the new American ships have already begun flight tests in low-Earth orbit.

Orion spacecraft
However, testing and fine-tuning the technology is a long and risky business. No one can guarantee that the new ships will be as safe as the good old Soyuz.
Modification of the Soyuz for flights to the Moon could become a lifesaver for Roscosmos and the entire Russian space program. So far, the United States has taken the lead in both the advanced spacecraft development program and the initiative to establish an outpost in deep space—the Deep Space Gateway (DSG) lunar platform. In any case, Roscosmos has joined cooperation with NASA as part of its new lunar program.

Deep Space Gateway lunar permanent orbital platform project
The DSG concept is not much different from the ISS: the same habitable modules, solar panels, radiators, etc. The only difference is that expeditions will visit it from time to time.
The Americans plan to begin implementing DSG as early as 2022 and are in dire need of a “Plan B” if something goes wrong.
Constant disruptions and delays in the development process of the Federation spacecraft, which is replacing the Soyuz, most likely forced Roscosmos to once again analyze the early proposals of specialists - to adapt old proven ships for flights to the Moon. Research results show that today Russian rocket scientists have every chance of not only sending the Soyuz to fly around the Moon, but also delivering the ship into lunar orbit.
For this, the Soyuz will need an additional accelerator. It could be the existing DM-03 upper stage, which is currently used to launch satellites into high Earth orbits.

Acceleration block DM
These upper stages can be launched into space separately, using the Proton launch vehicles from Baikonur, or the new Angara-5 launch vehicle from the Vostochny cosmodrome. In low Earth orbit, the Soyuz docks with the upper stage, which will take it to the Moon.
Back in the “holy nineties”, the first developer of the Soyuz, RSC Energia, on its own initiative, planned to build three-seater ships, the crews of which could fly around the Moon at an altitude of 90 km. Experts say that if the government had agreed and allocated money to them on time, the first Russian cosmonauts could have explored our natural satellite in close proximity as early as 2010.
The bet, however, was made first on the Clipper, and then on the four-seat Federation, specifically for launches from the new Vostochny cosmodrome.
RSC Energia did not give up, looked for private investors, tried to interest space tourists, but the price of a lunar ticket of $150 million scared off potential clients.

Project of a modified Soyuz spacecraft with a tourist lunar module
Over 25 billion rubles and ten years have already been spent on the Federation, but it still does not fly, although crew training is in full swing. If things continue in the same spirit, then the reputation of Roscosmos and the country as a whole will suffer heavy damage, and Russian cosmonauts, as part of the DSG cooperation program, will go to the Moon on American spacecraft.
It was announced that the first flight of the Federation should take place in 2022, but experts consider this period to be overly ambitious.
Thus, the Soyuz spacecraft, modified for flight to the Moon and back, becomes “Plan A” for Roscosmos. And perhaps for the Americans. While NASA suggests, Soyuz has it.
English version :: Read in English : Soyuz to the Moon! How about that, Elon Musk?