Mars 5
Launched by the USSR in 1973, Mars 5 was the only spacecraft of that window (Mars 4, 5, 6, 7) to successfully enter Mars orbit on February 12, 1974. However, a depressurization of the instrument compartment, likely due to a micrometeoroid, caused its failure after only 22 orbits and 16 days of operation, though it managed to return 43 high-quality images and surface data.