M-69 n°521

The Mars M-69 probes were originally intended to consist of both an orbiter and a lander. Time constraints did not permit the development of a soft lander, so engineers decided to simply use a hard lander that would crash into the Martian surface but gather data during its descent. At first, a modified Luna Ye-8 bus was to be used for the spacecraft, however it had a number of limitations that made it unsuitable for the long journey to Mars. Halfway through the project, Lavochkin Bureau design chief Georgi Babakin decided to simply discard the Luna E-8 derived probe and design a completely new one from scratch. However, the 2M probes ended significantly heavier than intended and engineers also ran out of time to conduct drop tests of the lander, so that part was abandoned which left only the orbiter. If successful, this would still be a major propaganda success for the Soviets as NASA was nearly three years away from attempting a Mars orbiter.