Soyuz 11A511M

Soyuz 11A511M

The Soyuz 11A511M is a Soviet expendable orbital launch vehicle developed and operated by the Soviet Space Program as part of the long-running Soyuz rocket family. A derivative of one of the most prolific launch vehicle lineages in spaceflight history, the 11A511M was designed to carry medium-weight payloads to low Earth orbit from Soviet launch facilities, primarily Plesetsk Cosmodrome in northern Russia.

Design and Capabilities

Standing 50 metres tall with a core diameter of 2.95 metres, the 11A511M follows the classic Soyuz configuration: a central core stage flanked by four strap-on boosters, topped by an upper stage and payload fairing. This arrangement, inherited from the R-7 ballistic missile lineage, gives the vehicle its distinctive tapered silhouette. The rocket is capable of delivering up to 6,600 kilograms to low Earth orbit, placing it firmly in the medium-lift category and making it well suited to the reconnaissance and remote-sensing satellites that formed the backbone of its mission manifest.

Role and Mission History

Our flight record tracks eight launches of the 11A511M, spanning the years 1971 to 1976, all of which were successful — a record of 8 successes and 0 failures or partial failures. This flawless performance, though across a relatively small number of flights, reflects the mature engineering foundation inherited from earlier Soyuz variants.

The vehicle's manifest was dominated by missions for the Soviet Space Program, with its most prominent payload being the Zenit-4MT series of reconnaissance satellites. The Zenit-4MT (also known in the Western literature under the Cosmos umbrella) was a film-return imaging satellite used for photographic reconnaissance, and the 11A511M served as its dedicated carrier throughout the mid-1970s. Tracked missions include Zenit-4MT flights numbered 3 through 10, illustrating a sustained and systematic deployment campaign across the vehicle's operational life.

Place in the Soyuz Family

The 11A511M occupies a specific niche within the broader Soyuz rocket genealogy, which evolved continuously from the late 1950s onward. Different sub-variants were optimized for different payload types — crewed Soyuz spacecraft, uncrewed Progress resupply missions, or, as in this case, military reconnaissance satellites. The 11A511M's relatively short operational window of five years reflects the pace at which the Soviet program cycled through successive vehicle configurations to meet evolving payload and mission requirements.

Legacy

Though the 11A511M flew only eight times in our records, it contributed meaningfully to the Soviet Union's strategic space capabilities during the early-to-mid 1970s. Its perfect success rate and focused role supporting the Zenit-4MT reconnaissance program demonstrate the efficiency with which the Soviet Space Program matched specific rocket variants to specific payload families. The Soyuz lineage to which it belongs remains, by total launch count, the most-flown rocket family in history — and the 11A511M represents one quiet but reliable chapter in that enduring story.