Launch Date Jan. 4, 1963
Launch Site Baikonur Cosmodrome, Kazakhstan, Russia |
Destination Earth’s Moon
Type Lander
Status Unsuccessful
Nation Soviet Union
Alternate Names Unnamed Luna, Sputnik 25, Sputnik 33 (USNSC), 00521, 1963-001A


This was the first Soviet spacecraft designed to make a survivable landing on the Moon. The 100 kilogram (220 pound) egg-shaped lander carried an imaging system and an instrument to measure radiation.


None. The spacecraft made it to Earth orbit, but a malfunction failed to send it on the Moon. It eventually burned up in Earth's atmosphere.

Key Dates

Jan. 4, 1963: Launch

In Depth

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

The Ye-6 probes were equipped with simple lander capsules (called the 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.

Like many of its deep space predecessors, this first Luna probe failed to escape Earth orbit because of a failure in the Blok L translunar injection stage. There was apparently a failure in the inverter in the power system of the I-100 guidance system (which controlled both the Blok L and the spacecraft), which failed to issue a command to fire the Blok L engine. The spacecraft remained in Earth orbit, unacknowledged by the Soviets.


Launch Vehicle: 8K78 (no. T103-09)

Spacecraft Mass: 1,420 kg

Spacecraft Instruments:

  1. imaging system
  2. radiation detector

Additional Resources

NSSDC Master Catalog: Sputnik 25

Selected References

Siddiqi, Asif A. Deep Space Chronicle: A Chronology of Deep Space and Planetary Probes 1958-2000, NASA, 2002

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