MOSCOW -- Cosmonaut Andrian Nikolayev, whose 1962 flight into space set an endurance record at the time, has died. He was 74 and suffered a heart attack Saturday in Cheboksary, the capital of his native Chuvash Autonomous Republic in central Russia, where he was judging the All-Russian rural sport games, the Interfax news agency reported.
Mr. Nikolayev became Russia's third cosmonaut to travel into space when he and Pavel Popovich were launched in separate crafts in August 1962. The pair made the first simultaneous flights, and Mr. Nikolayev set a separate endurance record, circling the Earth 64 times in 96 hours.
He returned to space in 1970 for his second and final mission onboard the Soyuz 9 craft. Altogether, he spent more than 200 hours in space, according to Russian media reports.
Twice named a Hero of the Soviet Union, Mr. Nikolayev was a key member of the proud Soviet cosmonaut corps, which included Yuri Gagarin, the first man to fly into space in 1961.
Mr. Nikolayev was married to Valentina Tereshkova, who in 1963 became the first woman to travel to space. They later divorced.