Russian cosmonaut Valery Polyakov has died aged 80. He conducted the longest continuous space flight ever. From January 8, 1994, to March 22, 1995, it orbited the Earth for 437 days and 18 hours.

In it, he orbited the planet about 7,000 times and covered an estimated 280 million kilometres. The Russian space agency Roskosmos announced the death of Polyakov on Monday.

Polyakov was a doctor. When a doctor flew to space for the first time in 1964, Polyakov decided to take the plunge too. He enlisted in the Soviet Union’s Space Agency and was selected in 1972. However, it took until 1988 before Polyakov could actually go to space. He spent 240 days in the Mir space station.

After his return to Earth, the Soviet Union fell apart. As a native of Russia, Polyakov made his second and final space journey, setting the record.

The mission was to examine how the body copes with such a long period of weightlessness. That could teach more about the possibilities of going to Mars and back someday. Muscles and bones weaken in space, and a trip to the red planet and back would take almost 2 years. According to Roskosmos, Polyakov proved that, in principle, the body and mind could cope with going far into space.

Polyakov retired as a cosmonaut after landing in 1995. However, he remained involved in space travel. For example, he helped prepare a project that would become the International Space Station.