Russian Orbital Service Station


The Russian Orbital Service Station is a proposed Russian orbital space station scheduled to begin construction in 2027. Initially an evolution of the Orbital Piloted Assembly and Experiment Complex concept, ROS developed into plans for a new standalone Russian space station built from scratch without modules from the Russian Orbital Segment of the ISS. However on December 2025, announced that ROS will once again be assembled as part of the ISS, and will be separated from the rest of the station shortly before it is scheduled to be deorbited by 2030.

Overview

In April 2021, Roscosmos officials announced plans to possibly exit from the International Space Station programme after 2024, stating concerns about the condition of its aging modules. On 26 July 2022, Roscosmos announced that the decision had been made to withdraw from the ISS programme after 2024. A new space station, named Russian Orbital Space Station, operated entirely by Roscosmos, would be launched starting in the mid-2020s.
In December 2024, Roscosmos head Yury Borisov stated crewed flights to the ROS would be launched starting in 2028, simultaneously with the completion of the ISS programme as coordinated with NASA.
ROS was originally planned to operate at a high, Sun-synchronous orbit with an inclination of about 98 degrees, which allowed remote sensing observations of the Arctic region, and conduct more medical and physiological experiments than those currently feasible on the Russian Orbital Segment of the ISS. Since December 2025, this has now changed to a 51.6-degree orbit after it was decided to be built from the ISS instead, which it will later share the same orbital plane as India's own Bharatiya Antariksh Station by 2040.

Assembly

, also known as Science Power Module 1, will be the core module of ROS. Initially intended to be launched to the International Space Station in 2024, NEM-1 will instead undergo 1.5–2 years of redesign to prepare the module for its new role as part of ROS., NEM-1 is scheduled to launch in 2027 on an Angara A5 launch vehicle from Vostochny Cosmodrome, and a new Core module is scheduled to launch no earlier than 2028.
ROS is envisioned to include up to seven modules, with 2035 being the targeted completion date. The first stage of construction will consist of four modules: the base NEM-1 module, an upgraded NEM, a node module, and a gateway module. The second stage will include logistics and production modules, as well as a platform module for servicing spacecraft. A commercial module for up to four space tourists is also under consideration.

Planned extravehicular components

There are plans for "multiple robotic systems on the exterior of the outpost to help with assembly and maintenance work". The station is also planned to control "a family of small spacecraft" to be launched directly from the station and "circl the globe in its vicinity", which would be a space first. A dedicated spaceplane was also proposed for their in-orbit maintenance.

Planned mode of operation

In contrast to the continuously crewed ISS, ROS will be visited by cosmonaut crews periodically, operating in automatic mode most of the time. During their stays, cosmonauts will install new components, check scientific equipment, conduct experiments and perform maintenance and repair tasks. Roscosmos cites not only financial, but also safety reasons for this, "as it reduces the risk of cosmonauts receiving dangerous radiation doses".