Mars probe intended to enter Martian orbit and comprehensively photograph Mars, together with a landing probe. Further Mars launches during the 1969 launch window were cancelled when this attempt resulted in a major accident, which almost wiped out all of the leaders of the space industry. The Proton rocket lifted off, but one engine failed. The vehicle flew at an altitude of 50 m horizontally, finally exploding only a short distance from the launch pad, spraying the whole complex with poisonous propellants that were quickly spread by the wind. Everyone took off in their autos to escape, but which direction to go? Finally it was decided that the launch point was the safest, but this proved to be even more dangerous - the second stage was still intact and liable to explode. The contamination was so bad that there was no way to clean up - the only possibility was just to wait for rain to wash it away. This didn't happen until the Mars launch window was closed, so the first such probe was not put into space until 1971. This accident also severely damaged plans to divert attention from America's Apollo programme during the rest of 1969. 10-12 UR-500K launches had been intended to land on the moon lunar soil return and rover robots to supplement the N1 launches.