This robotic Soviet mission was the first attempt by human beings to reach Mars, but a booster malfunction doomed it to fall back to Earth.


This was the first attempt to reach Mars.


This was the first of two Soviet Mars spacecraft intended to fly past Mars. It also was the first attempt by humans to send a spacecraft to the vicinity of Mars. Although the spacecraft initially included a TV imaging system (similar to the one carried on Luna 3), a UV spectrometer, and a spectroreflectometer (to detect organic life on Mars), mass constraints forced engineers to delete these instruments a week before launch.

A possibly apocryphal story has it that once removed from the spacecraft, the spectroreflectometer was tested not far from the Tyuratam launch site, but failed to detect any life.

The spacecraft itself was a cylinder, about 3 feet (1 meter) in diameter with all the basic systems required of interplanetary travel: A means to regulate temperatures, batteries charged by solar panels, a long-distance communication system, three-axis stabilization, and a mid-course correction engine (the S5.9).

The mission profile called for the probe to first enter Earth orbit and then use a new fourth stage (called “Blok L”) capable of firing in vacuum, to gain enough additional velocity for a Mars encounter. During the launch, violent vibrations caused a gyroscope to malfunction. As a result, the booster began to veer from its planned attitude. The guidance system failed at T+309.9 seconds and the third stage (Blok I) engine was shut down at T+324.2 seconds, after the trajectory deviated to greater than 7° (pitch).

The payload eventually burned up in Earth’s atmosphere over eastern Siberia without reaching Earth orbit.

The Mars flyby had been planned for May 13, 1961.


Siddiqi, Asif A. Beyond Earth: A Chronicle of Deep Space Exploration, 1958-2016. NASA History Program Office, 2018.

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