In July 1988, the Soviet Union launched two Phobos interplanetary stations to study Mars and its moon. The mission aimed to deploy landing modules on Phobos, including a hopping probe and seismic equipment. The stations were equipped with a complex scientific suite, including plasma analyzers, magnetometers, and the Terek telescope for solar observation.
The Phobos-1 station was lost on September 2, 1988, due to a software error. A missing character in a ground-based command file caused the station to shut down its orientation engine valves. Without proper orientation, the solar panels failed to receive sunlight, leading to battery depletion. The error was not caught by ground testing or onboard automation.
Phobos-2 reached Mars orbit on January 29, 1989. It conducted thermal imaging of the Martian surface using the Thermoscan radiometer and gathered spectral data with the ISM instrument. The mission ended prematurely due to a suspected electronics failure. Despite the loss of both stations, the project provided valuable scientific data on the Sun, Mars, and Phobos.
The project featured significant international cooperation, particularly with the European Space Agency. The stations, weighing approximately 6.22 tons each, were based on the 1F series developed by the Lavochkin Research and Production Association. The mission highlighted critical issues in Soviet space engineering, including insufficient testing and design vulnerabilities.
