On 10th May 1971, the Soviet Union launched its first interplanetary mission to Mars. The mission was a big success and marked a major milestone in the history of space exploration. It also marked the beginning of a new era of space exploration as the mission marked the first time a spacecraft from Earth has successfully reached and explored another planet.

The Soviet Union had been exploring space since October 4th 1957 when it launched the world's first artificial satellite, Sputnik 1, into orbit. This was followed by the launch of the first human into space, Yuri Gagarin, in April 1961. After a series of robotic probe missions to the Moon, the Soviet Union set its sights on Mars.

In October 1969, the Soviet Union sent the first robotic spacecraft to Mars, named Mars 3. The spacecraft was designed to take pictures of the planet's surface and to measure its atmosphere. Unfortunately, the mission was unsuccessful as the spacecraft malfunctioned and only sent back 20 seconds of data before it crashed into the Martian surface.

But the Soviets were undeterred and they launched the unmanned Mars 5 mission in May 1971. This mission was a success and the spacecraft was able to transmit data back to Earth for a total of 20 days. It sent back a total of about 6300 images of Mars.

The mission also included an orbiter, Mars 6, which was launched in August 1971. It was designed to measure the properties of the Martian atmosphere, including its composition and temperature. The mission was also successful and sent back data for a total of 11 days.

But the most important mission of all was the Mars 7 mission. Launched in August 1971, this mission was designed to land an unmanned probe on the Martian surface. The probe was to collect samples of the Martian soil and analyze them for evidence of life. Unfortunately, the mission failed and the probe missed the planet's atmosphere and crashed onto the surface.

Despite the failure of Mars 7, the Soviet Union's first interplanetary mission to Mars was a success. It was the first time a spacecraft from Earth had successfully reached and explored another planet. It was also a major milestone in the history of space exploration and marked the beginning of a new era of exploration. The mission showed that humans could explore the universe and that space exploration was no longer just a dream.