L1 Overhead Soyuz 7K-L1 circumlunar spacecraft. 17,001 bytes. 424 x 253 pixels.

Hybrid spacecraft used in N1 launch tests. The L1S consisted of the Soyuz LOK service module, or a standard Soyuz L1 service module attached to an LOK-sized flange, with a boilerplate Soyuz descent module, topped by an odd propulsion module derived from that to be used on the LK lunar lander. Probably each L1S differed somewhat from the other, using available surplus components or systems ready for test in space. References: 21 , 102 .

• N-1 3L Program: Lunar L3.

  N-1 serial number 3L was the first N-1 launched. As a result of a rising high frequency oscillation in the gas generator of engine number two, some engine components tore off their mounts, resulting in a forced leak of propellants, setting in motion a fire in the tail compartment. The BKS engine monitoring system detected the fire, but then gave an incorrect signal shutting down all engines at 68.7 seconds into the flight. The vehicle was destroyed by range safety 70 seconds into the flight. The escape tower did not work as designed. British intelligence detected the launch attempt, but the CIA's technical means for some reason missed it and they denied for years that it had ever occurred. More details

• N-1 5L Program: Lunar L3.

  N-1 serial number 5L began to fail at 0.25 second after liftoff when the oxidizer pump of engine number 8 ingested a slag fragment and exploded. A fire ensued as the vehicle climbed past the top of the tower. Engines were shutdown until the acceleration dropped below 1 G; then the vehicle began to fall back to the pad at a 45 degree angle. The escape tower fired at the top of the brief trajectory, taking the L1S dummy descent module away from the pad. Upon impact of the base of the N1 with the pad, the vehicle exploded, destroying launch pad 110 east, which would take over 18 months to repair. More details