Fast Facts: Unnamed Moon Mission (Ye-6 No. 2)

This Soviet lunar lander was stranded in Earth orbit after an engine failed to fire. It burned up in Earth's atmosphere a week later. The mission was not acknowledged at the time by the Soviet Union. Historians have identified it as part of the Soviet Luna series of Moon missions.

Nation Union of Soviet Socialist Republics (USSR)
Objective(s) Lunar Soft-Landing
Spacecraft Ye-6 (No. 2)
Spacecraft Mass 3,131 Pounds (1,420 Kilograms)
Mission Design and Management OKB-1
Launch Vehicle Molniya + Blok L (8K78 no. T103-09)
Launch Date and Time Jan. 4, 1963 / 08:48:58 UT
Launch Site NIIP-5 / Site 1/5
Scientific Instruments 1. Imaging System
2. Gas-Discharge Counter


This spacecraft was the first “second generation” Soviet lunar probe (known as Ye-6), designed to accomplish a survivable landing on the surface of the Moon.

The Ye-6 probes were equipped with simple 220 pound (100-kilogram) lander capsules (called the Automatic Lunar Station or Avtomaticheskaya lunnaya stantsiya, ALS) whose primary objective was to send back photographs from the lunar surface. Each egg-shaped ALS was installed on a roughly cylindrical-shaped main bus.

Like the Mars and Venera deep space probes, the Ye-6 Luna spacecraft were also launched by the four-stage 8K78 (Molniya) booster, but modified for lunar missions. This first Ye-6 probe was designed to cruise for about three days before landing on the Moon on Jan. 7, 1963 at 19:55:10 UT.

Like many of its deep space predecessors, the probe failed to escape Earth orbit because of a failure in the Blok L translunar injection stage. There was apparently a failure in a current converter in the power system of the I-100 instrument container (which controlled both the Blok L and the spacecraft), which as a result, failed to issue a command to fire the Blok L engine. The spacecraft remained in Earth orbit, unacknowledged by the Soviets until Jan. 11, 1963.


Siddiqi, Asif A. Beyond Earth: A Chronicle of Deep Space Exploration, 1958-2016. NASA History Program Office, 2018.

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