33. Apollo-Soyuz, 1975 Alexei Leonov (left) had trained to be the first Soviet man on the moon. Mercury astronaut Deke Slayton had been sidelined for years due to a heart condition. Their “handshake in space” in July 1975 had more to do with U.S.-Soviet détente than with space exploration.
Photos from: "Top NASA Photos of All Time" »