July 1969 was the most dramatic month in space history, and not only because it marked the first time humans ever set foot on the Moon. On July 3, just a few weeks before Apollo 11 made its momentous landing, the apocalyptic launchpad detonation of the Soviet N1 rocket further dashed the USSR's own ambitions for manned lunar landings.
Releasing nearly as much energy as a nuclear bomb, it was the largest rocket explosion in history, according to space historian Anatoly Zak. See the pyrotechnics for yourself with this footage of the blast.
Here's another view:
It must have been horribly demoralizing for Soviet space officials, who had pinned all their Moon landing hopes on the N1, to see the vehicle literally blow up in their faces mere weeks before the United States celebrated the Eagle's landing.
"Today...I saw without exaggeration the end of the world, and not in a nightmare but while fully awake and standing right next to it," said eyewitness Lieutenant Colonel Semen Komarovsky.
Though no fatalities were reported, the blazing inferno completely leveled the launchpad at Site 110 of the Baikonur Cosmodrome in Kazakhstan. Rocket debris was hurtled as far as ten kilometers from the blast epicenter, and windows of the surrounding communities were shattered as far as 40 kilometers distant.
What's even crazier is that the blast could have inflicted much more damage, but fortunately, only the first stage ignited as the rocket crashed back down on the launchpad. A subsequent investigation concluded that the accident was sparked by a malfunctioning turbopump within N1 engine number 8. Officials speculated that a piece of foreign debris may have been sucked into the pump, prompting it to jam and explode.
The July 3 explosion set the N1 Moon rocket project back for two years, and the immensity of the damage was what first tipped off the US to their rivals' lunar efforts. After the next two launches in June 1971 and November 1972 also ended in flames, the Soviet crewed Moon landing program was abandoned, though the badass design of the N1 will live on forever.