Mars 5M grew out of the
Mars 5NM and
Mars 4NM missions that were canceled along with their intended launch vehicle, the
N1 rocket, in 1974. The following year, Soviet Minister of Defence
Dmitry Ustinov, at the urging of
Alexander Pavlovich Vinogradov, directed
Lavochkin to develop 5M as a sample return mission to launch in 1980. The launch vehicle was to be the heavy
Proton rocket, using two rockets to send the lander out of Earth orbit to Mars, where it would land, collect samples, and separate for return, with a stage returning to Mars orbit to rendezvous with a return spacecraft delivered by another Proton. The return craft was originally to dock with a station in Earth orbit, though in the final design, which was completed in January 1976, had it travel directly to Earth after sterilizing the samples via heat. To save weight, the return craft would crash land on earth without parachutes, and would be located via a radioactive beacon. Though the Soviet government approved the mission, and production of equipment began in 1977, it was later deemed unfeasible and with proponent Vinogradov having died it was canceled by the end of the year. ==References==