NASA Insignia
Imagine the Universe!

Mars Program

The Mars 4 spacecraft.

The Mars 4 spacecraft. (Credit: Soviet Space Program)

The Mars program was a series of Soviet scientific probes sent to explore Mars. The probes included fly-bys, landers, and orbiters.

Lifetime: October 1960 (first attempted launch, Mars 1M) - March 1974 (last probe in series missed Mars and enters heliocentric orbit)

Country (primary): Soviet Union

Primary Science

The Mars Program probes were intended to explore Mars. These studies included photography of the surface during fly-bys, gathering data on cosmic radiation and micormeteoriods near Mars, can the atmospheric structure of Mars.

High Energy Science

Mars 4 and Mars 5 each carried gamma-ray spectrometers. These were primarily intended to study the spectral composition of gamma rays from Mars. However, they were also used for a series of measurements of the cosmic gamma-ray background while the spacecraft were in-flight to Mars.

Science Highlights

  • Determined an average cosmic gamma-radiation background flux density.

Links to more information

Mars 4

Lifetime: July 1973 - February 1974

Mars 5

Lifetime: July 1973 - February 1974