Target: Venus . The Soviet VEGA Spacecraft Two remarkable "busloads" of automated spacecraft were launched toward Venus by the Soviet Union in December of 1984. Each one contains three separate modules: one lander and one balloon-carried atmosphere probe to be dropped off at Venus in June, 1985, and one major package of instruments which will continue on to encounter Halley's Comet in March, 1986. ... Venus and Earth: A Comparison . Earth . ... in Earth days) . ... 243 Earth days . ...