Crater Tsiolkovsky. Apollo 15 image of the flow structure on the rim of the crater Tsiolkovsky on the farside of the Moon. The Moon's orbit of Earth is locked so that only one hemisphere faces Earth at all times. The far side was seen for the first time when Russian probes photographed it in the late 1950s, and many of the named features on that side are named after Russians. Apollo 15, which launched on 26th July 1971, was the fourth mission to land on the Moon.