The Ye-8 represented the “third generation” of Soviet robotic lunar probes. The basic Ye-8 comprised a lander stage, the KT, topped off by an eight-wheeled remote-controlled lunar rover , the 8YeL, for exploring the Moon’s surface.
Essentially a pressurized magnesium alloy container on wheels, the 8YeL was designed to operate over a period of three lunar days (roughly three Earth months) and to collect scientific data from various points on the lunar surface.
This first attempt to put a rover on the Moon was a complete failure. At T+51.42 seconds, the payload stack disintegrated and the booster exploded at T+54 seconds. Debris landed about 9 miles (15 kilometers) from the launch site.
Later investigation indicated that maximum dynamic pressure during the ascent trajectory tore the new and untested payload shroud off at its weakest tension points.
Despite an intensive effort, searchers were unable to find the polonium-210 radioactive isotope heat source in the rover. Unconfirmed rumors still abound that soldiers at the launch site used the isotope to heat their barracks during the bitter winter of 1968 to 1969.
Siddiqi, Asif A. Beyond Earth: A Chronicle of Deep Space Exploration, 1958-2016. NASA History Program Office, 2018.