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Mission record

Cosmos 300

Also known as Cosmos300, Kosmos 300

U.S.S.R · Launched

Explore trajectory

Failed · Failure

A Soviet lunar mission that reached Earth orbit but failed to leave it, and so received a Cosmos designation.

Destinations
Moon
Launch vehicle
Proton
Launch site
Tyuratam (Baikonur Cosmodrome), U.S.S.R
Countries
Soviet Union
Mission types
Sample return

Chronology

Mission timeline

  1. Launch

    Cosmos 300 launched from Baikonur Cosmodrome

  2. Milestone

    The Block D stage failed, leaving the spacecraft in Earth orbit

    The cited page records the failure and the resulting Cosmos designation without giving a date for it.

    Earth

Mission architecture

Vehicles

  • Cosmos 300 · Spacecraft

    Destinations: Moon

Trajectory record

Trajectory dataset not yet available

No verified trajectory dataset is committed for this mission, so Mission Atlas renders no path.

Provenance

Sources

Each source is listed once and labeled with the mission, event, trajectory, or destination/body context it supports.

Data verified through August 27, 2026