rocket. After Apollo 8 won the first (lunar orbit) phase of the Moon Race at the end of 1968, the Soviet leadership lost political interest in the L1 (Zond) program. A few reserve units of L1 (Zond) made unpiloted flights, but by the end of 1970, this program was canceled. Moon landing N1/L3 program The crewed landing plan adopted a similar method to the single launch and lunar orbit rendezvous of the Apollo project. For mission safety, weeks before the crewed mission, an LK-R uncrewed L3 complex and two Lunokhod automated rovers would be sent to the Moon, to work as radio beacons for crewed LK, with the LK-R used as a reserve escape craft. The Lunokhods were also equipped with manual controls for the cosmonauts, both for transfer to LK-R in necessity and for regular research. The N1 rocket would then carry the L3 Moon expedition complex, with two spacecraft (LOK and LK) and two (Block G and Block D) boosters. A variant of the Soyuz craft, the "Lunniy Orbitalny Korabl" (LOK) command module, would carry two men, with three modules like the regular Soyuz 7K-OK, but was heavier by a few tons. The 7K-OK was half the mass of the three-crew Apollo orbital command ship. The "Lunniy Korabl" (LK) accommodated only one cosmonaut, so in the Soviet plan, only one cosmonaut would land on the Moon. The mass of the LK was 40% of the mass of the Apollo lunar lander. The L3 complex to be placed in LEO by the N1 was 93 tons (compared to Saturn V's 137 tons). The mass of the LOK and LK was 40% of the Apollo complex, but was equivalent to the L3 complex without Block G. The booster for the LEO toward the Moon for the Apollo vehicle was provided by the last stage of the Saturn V, while for the Block D, LOK and LK, this was to be provided by Block G of the same L3 complex. During the L3 complex's journey to the Moon, there would be no need to undock and re-dock the orbital and landing craft as was done in Apollo, because the cosmonaut would transfer from the LOK to LK by a 'spacewalk'. On the Apollo missions, the transfer was done using an internal passage. Block D was to slow the LOK and LK into lunar orbit, while with Apollo this phase was undertaken