The Soviet Union makes its final attempt at successfully launching the N1 rocket.
The N1/L3 (from Ракета-носитель Raketa-nositel', "Carrier Rocket"; Cyrillic: Н1) was a super heavy-lift launch vehicle intended to deliver payloads beyond low Earth orbit. The N1 was the Soviet counterpart to the US Saturn V and was intended to enable crewed travel to Earth's Moon and beyond, with studies beginning as early as 1959. Its first stage remains one of the most powerful rocket stages ever built, However, all of the four flown N1 Block A first stages failed because a lack of static test firings meant that plumbing issues and other adverse characteristics with the large cluster of thirty engines and its complex fuel and oxidizer feeder system were not revealed earlier.The N1-L3 version was designed to compete with the United States Apollo program to land a person on the Moon, using a similar lunar orbit rendezvous method. The basic N1 launch vehicle had three stages, which were to carry the L3 lunar payload into low Earth orbit with two cosmonauts. The L3 contained one stage for trans-lunar injection; another stage used for mid-course corrections, lunar orbit insertion, and the first part of the descent to the lunar surface; a single-pilot LK Lander spacecraft; and a two-pilot Soyuz 7K-LOK lunar orbital spacecraft for return to Earth.
N1-L3 was underfunded and rushed, starting development in October 1965, almost four years after the Saturn V. The project was badly derailed by the death of its chief designer Sergei Korolev in 1966. Each of the four attempts to launch an N1 failed, with the second attempt resulting in the vehicle crashing back onto its launch pad shortly after liftoff and causing one of the largest artificial non-nuclear explosions in human history. The N1 program was suspended in 1974, and officially canceled in 1976. All details of the Soviet crewed lunar programs were kept secret until the Soviet Union was nearing collapse in 1989.