Possible Clues:

• Series of six manned Soviet orbiting spacecraft
• Name, meaning “east”, for the USSR’s first manned spaceflight project
• Craft in which Yuri Gagarin became the first man in space
• ___ 1, Yuri Gagarin's spacecraft
• Soviet spacecraft series
• Early Soviet space program
• Any of six manned Russian spacecraft launched between 1961 and 1963
• ___ 1, Yuri Gagarin's spacecraft
• __ 1: first manned space mission carrying Yuri Gagarin