The rocky Soviet road to Mars.

The history of the Soviet space program is reviewed with particular attention given to the Soviet Mars exploration program. Missions of the Mars and Zond series and their exploration of Mars are described in detail, and the progress of the Soviet Mars exploration program is compared and contrasted with that of U.S. programs. Soviet space exploration in the 1980s is reviewed, noting that changes in political climate enabled more open discussion of the Phobos mission, which facilitated both international cooperation in assembling the craft and extensive U.S.-Soviet cooperation in the communications aspect of the probe through use of NASA's Deep Space Network of radio telescopes. The Phobos 1 and Phobos 2 missions are discussed and reasons for difficulties are analyzed; the future of the Soviet Mars program is reviewed.