Memorial services were held at the ex-Soviet Baikonur cosmodrome, now in Kazakhstan where the R-16 rocket exploded this day in 1960 and the public was informed of this accident only in mid-1990s after the Soviet collapse, Rossiya 24 channel reported.
The cause of the accident has not been established so far.
"It was a sea of fire, the engine self ignited and its flame started burning the first stage. I ran away. Chief designer Yangel was standing 8-10 meters away from me. Our Marshal, the commanding officer was sitting little close to the rocket, he was simply charred," Baikonur veteran Boris Aleksin recalled in interview to the channel.
Exactly three years later in 1963, more people were killed in explosion of another rocket on the launch pad on same day.
In the wake of the two accidents, October 24 is known as "a black day" for space exploration on which Russian officials commemorate the memory of all those who dedicated their lives to the space programme.
In the West, the tragedy is referred to as "Nedelin's" after Artillery Marshal, Hero of Soviet Union Mitrofan Nedelin, who was virtually evaporated in the fire only his badge of the parliament member was recovered and his family was told that he died in a plane accident.