Soviet cosmonaut Alexei Leonov died in a Moscow hospital after a long illness.
The cosmonaut made history in 1965, when he stepped outside his spacecraft for just over 12 minutes and floated around, attached by a tether.
In 1975, Leonov commanded the Soviet crew during the Apollo-Soyuz mission, in which the American module docked with the Soviet craft.
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"This is a bittersweet day for all of us on the International Space Station", said Italian astronaut Luca Parmitano, who met Leonov in years past. From left to right, Alexey Leonov, Charles Conrad Jr.
"Farewell, Alexei, and Ad Astra". The duo, Andrew Morgan and Christina Koch, are now maneuvering around the exterior of the space station as they remove old batteries and attach new, more efficient replacements. The old nickel-hydrogen batteries on the exterior of the space station have to be detached from their mounting points, stowed, and then new lithium-ion batteries have to be installed. With that successfully behind them, they got a jump on next week's spacewalk. Morgan will be accompanied Wednesday by NASA's Jessica Meir, the other woman on board. The form of the medal itself was inspired by Leonov's drawing, his first spacewalk and the home-built electric guitar of Queen band member and astrophysicist Brian May.
Russian cosmonauts and American astronauts join hands at a hotel in Athens, Greece, September 1965.
The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute's Department of Science Education.