NEW YORK, October 11. /TASS/. Russian cosmonaut Alexey Leonov, who became the first human to walk in space, was a cosmonaut ambassador to the world, US Astronaut Buzz Aldrin wrote on Twitter on Friday.

Buzz Aldrin alongside Neil Armstrong were the first humans to step on the moon on July 20, 1969.

"The Cosmonaut ambassador to the world. A great pleasure to be his friend. He tried for the moon but we made it. For space flyers friendships he helped formed the @ASE_Astronauts [Association of Space Explorers - TASS]," he wrote offering condolences.

"Farewell and Godspeed Alexi," Aldrin tweeted.

Alexey Leonov passed away in Moscow aged 85, his aide Natalia Filimonova told TASS on Friday.

On May 30, Leonov celebrated his 85th birthday. Members of the International Space Station’s crew Oleg Kononenko and Alexei Ovchinin dedicated their May 29 spacewalk to Leonov’s jubilee. Inscriptions on their spacesuits read "Leonov N. 1" and "Happy Birthday, Alexei Arkhipovich". Also, they took Leonov’s portrait outside the ISS.

Leonov made two space flights that lasted a total of seven days and 33 minutes. The first one was on March 18-19, 1965. Leonov was a co-pilot of the spacecraft Voskhod-2 (commander Pavel Belyayev). During that space mission Leonov performed the first-ever spacewalk. During his second space voyage on July 15-21, 1975 Leonov was the commander of the crew that participated in the first international docking of the Soviet Union’s Soyuz-19 spacecraft and the United States’ Apollo-18. The handshakes of Soviet and US crewmembers Alexei Leonov, Valery Kubasov, Vance Brand, Thomas Stafford and Donald Slayton in orbit went down in the history of space exploration.