Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. ZOndwas the name given to two series of Soviet unmanned space missions undertaken from 1964 to 1970 to gather information about nearby planets and to test spacecraft. THe second series used a stripped-down variant of the manned Soyuz spacecraft, consisting of the service and descent modules, but lacking the orbital module.THe first three missions were based on the model 3MV planetary probe, intended to explore Venus and Mars. AFter two failures, Zond 3 was sent on a test mission, photographing the far side of the Moon (only the second spacecraft to do so) and continuing out to the orbit of Mars in order to test telemetry and spacecraft systems.THe missions 4 through 8 were test flights under for the Soviet Moonshot during the Moon race. THe Soyuz 7K-L1 (also mentioned just as L1) spacecraft was used for the moon-aimed missions, stripped down to make it possible to launch around the moon from the Earth. THey were launched on the Proton rocket which was just powerful enough to send the Zond on a free-return trajectory around the moon without going into lunar orbit (the same path that Apollo 13 flew in its emergency abort).