The Russian is serving aboard the International Space Station

He beat a previous record of 747 days, 14 hours, 14 minutes and 11 seconds held by fellow Russian Sergei Avdeyev.

Krikalev is the current commander of the International Space Station (ISS) and is scheduled to stay on board the orbiting platform until October.

He has also stayed aboard the Mir space station during his 20-year career.

The cosmonaut is serving out a stint on the ISS that began on 14 April. Together with Nasa astronaut John Phillips, he hosted the crew of space shuttle Discovery when they arrived at the station in July.

Long duration

Sergei Krikalev was born in Leningrad (now St Petersburg), Russia, in 1958.

Krikalev served aboard the first US-Russian shuttle mission

The 46-year-old was selected as a cosmonaut in 1985 and completed his basic training in 1986.

He made his first long-duration mission to the Russian Mir space station in 1988.

The cosmonaut flew aboard space shuttle Discovery on STS-60, the first joint US/Russian shuttle mission in 1994. He was also part of the first crew to stay aboard the International Space Station.

Krikalev and Phillips are due to return to Earth on 7 October. But they are currently preparing for two spacewalks, the first of which takes place on Thursday.

They will replace experiments, install a television camera, and move equipment during the scheduled six-hour extra-vehicular activity (EVA).