821st Space Situation Monitoring Main Center
System Overview: Russian Space Surveillance (SKKP) and the 821st Main Center
Russia’s Space Surveillance System (SKKP) is operated by the Space Forces, a branch of the Russian Aerospace Forces (VKS) established on 1 August 2015 by merging the Air Force and the Aerospace Defense Forces. The 821st Space Situation Monitoring Main Center (also known as the Main Center for Reconnaissance of the Space Situation), military unit 61437, is the central command-and-analytic node of the SKKP. It consolidates observations from ground-based radar and optical assets, maintains Russia’s Main Catalog of Space Objects, and provides space domain awareness support for national space operations and related defense missions.
Headquarters and Location (military unit 61437)
The 821st Main Center headquarters and primary command post are located in Dubrovo, Noginsk District, Moscow Oblast (often referred to in open sources as Noginsk-9), Russian Federation. The site functions as the central control, data fusion, and catalog-maintenance hub for Russia’s space situational awareness network. Specific internal facility layouts, staffing levels, and protected infrastructure at this location are not publicly disclosed.
Core Missions and Functions of the 821st Main Center
The center’s publicly stated tasks include: maintaining the national Main Catalog of Space Objects; detecting, tracking, and characterizing resident space objects from low Earth orbit through geosynchronous regimes using multi-sensor inputs; issuing tasking to subordinate and cooperating sensor nodes; conducting orbit determination and correlation; and providing space awareness products to Russian space operators and defense authorities. The center employs automated control and data-processing systems for continuous operations; detailed software architectures and performance parameters are not publicly available.
145th Space Control Center (military unit 28289)
The 145th Space Control Center is an operational element associated with the 821st Main Center. Open reporting attributes to it round-the-clock processing of measurement data from the SKKP’s ground-based radar and optical sensors, refinement of orbital solutions, and support to catalog maintenance and warning functions. Specific manning, internal structure, and site details for military unit 28289 are not officially published.
Information and Analytical Point (military unit 41646)
Military unit 41646 is identified as an Information and Analytical Point linked to the space surveillance mission set. Publicly available information indicates an analytical role focused on data conditioning, correlation, and product generation in support of the Main Catalog and operational decision-making. Precise location, hardware configuration, and organizational subordination beyond this functional description are not disclosed in open sources.
Office for the Introduction of New Systems and Complexes of the Space Forces (military unit 73570)
Military unit 73570 is identified as the Office for the Introduction of New Systems and Complexes of the Space Forces. Based on its designation, the office is responsible for testing, acceptance, and fielding of new equipment and software within the Space Forces, including space surveillance assets and associated automation. Specific programs under its remit, facility locations, and detailed timelines are not publicly detailed.
1109th Separate Optoelectronic Unit (military unit 52168)
The 1109th Separate Optoelectronic Unit operates the Okno optical space surveillance complex near Nurek, Tajikistan. Open sources consistently associate military unit 52168 with this site. The unit conducts passive optical detection and tracking of satellites at medium and high altitudes and supports the Main Catalog with photometric and astrometric measurements. Exact personnel strength, equipment lists by model, and duty-cycle metrics are not officially released.
Okno and Okno-M Optical Complex
Okno is an automated, passive, multitelescopic optical complex located in the Sanglok mountains near Nurek, Tajikistan, at high elevation to reduce atmospheric distortion. It is optimized for detecting and tracking objects in medium, high, and geosynchronous orbits and operates at night using reflected sunlight. According to Russian Ministry of Defense statements in open reporting, Okno entered service in the early 2000s; subsequent modernization under the designation Okno-M expanded capabilities. Public sources commonly cite an altitude coverage on the order of roughly 2,000 to 40,000 km for the system. Detailed sensitivity, limiting magnitude, sensor aperture counts, and processing throughput figures remain undisclosed.
Legal Status and Basing Arrangements for Okno in Tajikistan
In 2004, Tajikistan and Russia concluded agreements that transferred the Okno complex to Russian ownership and control; the arrangements were publicly reported to include Russian debt relief for Tajikistan. Since then, Okno has been operated by the Russian Space Forces with Tajikistan’s consent. The specific terms, durations, and technical annexes of these intergovernmental agreements are not fully published in the public domain.
Sensor Network Integrated by the 821st Main Center
The 821st fuses data from a distributed network of ground-based sensors, including: the Okno and Okno-M optical complexes in Tajikistan; the Krona radar-optical complex near Zelenchukskaya and its Far Eastern counterpart Krona-N; the Don-2N multifunction radar near Sofrino in Moscow Oblast, which has a documented space-tracking role; and early-warning radars of the Voronezh and legacy families that provide additional tracking data on space objects. The precise sensor list, tasking priorities, and data-sharing interfaces are not comprehensively public.
Data Handling and the Main Catalog of Space Objects
The 821st maintains Russia’s Main Catalog of Space Objects, which stores orbital elements and characteristics of resident space objects and supports functions such as object identification, conjunction analysis for Russian satellites, and observation planning. The catalog is maintained through continuous ingestion of measurements from radar and optical assets and subsequent correlation and orbit-determination processes within automated control systems of the SKKP. Detailed catalog size, update rates, and export policies are not officially disclosed.
Operational Considerations and Limitations
Optical complexes such as Okno and Okno-M provide high-precision angular measurements but require nighttime conditions with clear skies and sunlit targets, which imposes diurnal and meteorological constraints. Radar assets provide all-weather, day-night coverage but have range, sensitivity, and field-of-view constraints tied to frequency, power, and antenna geometry. The SKKP’s architecture mitigates single-sensor limitations by multi-sensor tasking and data fusion through the 821st Main Center.
Organizational Context within the Aerospace Forces
Following the 2015 establishment of the Russian Aerospace Forces, the Space Forces retained responsibility for space launch, on-orbit control, and space situational awareness. The 821st Main Center (military unit 61437) performs the SSA mission set and exercises operational integration with subordinate and cooperating units, including the 145th Space Control Center (military unit 28289), the Information and Analytical Point (military unit 41646), and sensor-operating units such as the 1109th Separate Optoelectronic Unit (military unit 52168).
Recent Publicly Reported Modernization (2010s–2024)
Russian Ministry of Defense communications in the 2010s and early 2020s referred to modernization of space surveillance facilities, including upgrades to the Okno complex under the Okno-M program, improvements at Krona and Krona-N, and enhancements to automated control and data-processing systems supporting the SKKP. Specific performance deltas, project schedules, and software baselines tied to these upgrades are not publicly detailed.
Security and Access
The 821st Main Center headquarters at Dubrovo and associated facilities operate as restricted military sites. The Okno complex in Tajikistan is guarded and controlled by the Russian military under bilateral agreements. Public access to these facilities is not permitted, and imagery or documentation revealing internal layouts, communications infrastructure, and protected systems is limited by security regulations.
Data Limitations
Many details about these units are not publicly available or are classified, including internal organization charts, staffing, equipment technical specifications, duty schedules, and real-time operational procedures. The analysis above relies on information that has appeared in official Russian statements and widely cited open sources; where precise data are not released, functions are described at a general level without speculative assessments.