This test of a powerful Soviet Moon rocket ended with an explosion seconds after launch.
This was the second attempt to launch the giant N1 rocket. Like its predecessor, its payload consisted of a basic 7K-L1 spacecraft equipped with additional instrumentation and an attitude control block to enable operations in lunar orbit.
Moments after launch, the first stage of the booster exploded in a massive inferno that engulfed the entire launch pad and damaged nearby buildings and structures for several miles (kilometers) around the area.
Amazingly, the payload’s launch escape system fired successfully at T+14.5 seconds and the 7K-L1 descent module was recovered safely about 1 mile (2 kilometers) from the pad.
An investigation commission traced the cause of the failure to the entry of a foreign object into the oxidizer pump of one of the first stage engines at T-0.25 seconds. The ensuing explosion started a fire that began to engulf the first stage. The control system shut down all engines except one by T+10.15 seconds. The booster lifted about 656 feet (200 meters) off the pad and then came crashing down in a massive explosion.
Some estimates suggest that the resulting explosion had a power of about 25 tons of TNT.
Siddiqi, Asif A. Beyond Earth: A Chronicle of Deep Space Exploration, 1958-2016. NASA History Program Office, 2018.