who made the longest-ever solo space flight, orbiting the Earth 81 times over a period of five days in June 1963. During the last three days, Valentina Tereshkova was in orbit simultaneously aboard Vostok 6. He made two subsequent flights, aboard Soyuz 22 in 1976 and Soyuz 31 in 1978. Bykovsky left the cosmonaut program in 1988 to become director of the House of Soviet Science and Culture in Berlin, where he stayed until 1990.