USE WITH KLIPER SPACEPLANE

The 6,800-kilogram unmanned Parom orbital tug --(a reminiscent of the Soviet-era TKS spacecraft)-- would carry propulsion system for orbital maneuvering and additional habitation volume.
The vehicle could be launched ahead of the Kliper and wait for the latter in a parking orbit or at the space station.

Upon the Kliper launch, the two vehicles would dock, and the Parom would then provide all orbital maneuvering and attitude control necessary to reach the space station or higher orbits. At the conclusion of the flight, the Kliper, carrying the crew, would reenter the atmosphere and glide to Earth, while the Parom, with enough propellant onboard, could return to the space station, awaiting next manned mission.

The modular nature of the Parom spacecraft adds a potential for virtually unlimited upgrades of the vehicle. As a result, the Kliper-Parom combination could become a foundation for the manned exploration of the Moon and even expeditions to Mars