The N1 was a super heavy-lift launch vehicle intended to deliver payloads beyond low Earth orbit, acting as the Soviet counterpart to the US Saturn V. It was designed with crewed extra-orbital travel in mind. Development work started on the N1 in 1959. Its first stage is the most powerful rocket stage ever built.
Each of the four attempts to launch an N1 failed; during the second launch attempt the N1 rocket crashed back onto its launch pad shortly after liftoff and exploded, resulting in one of the largest artificial non-nuclear explosions in human history. The N1 program was suspended in 1974, and in 1976 was officially canceled. Along with the rest of the Soviet manned lunar programs, the N1 was kept secret almost until the collapse of the Soviet Union in December 1991; information about the N1 was first published in 1989.
