Mission Summary
This spacecraft was the Soviet Union’s first attempt to soft-land on the Moon, the opening move of the ambitious Ye-6 program that would not succeed until Luna 9 three years later. Launched January 4, 1963, it carried a small egg-shaped capsule designed to settle onto the surface and transmit the first photographs from the Moon.
The probe reached a low Earth parking orbit as planned, but the mission depended on a Blok L escape stage to boost it onto a lunar trajectory. A failure struck the power-system current converter inside the I-100 control container, the unit that governed both the booster stage and the spacecraft. Deprived of its firing command, the Blok L engine never ignited.
Stranded in orbit and unacknowledged by Soviet authorities, the spacecraft circled the Earth until it decayed on January 11, 1963. Western trackers cataloged the silent vehicle as Sputnik 25. The flight opened a long run of Ye-6 setbacks, each one refining the design that eventually carried Luna 9 to the surface.
Sources and notes can be found on the Sources page.
