Ten KNIGA covers, all with cachets commemorating Russian space achievements, issued and cancelled to mark one of the first six Russian manned space missions. Each signed in ink by the respective cosmonaut: Yuri Gagarin, Gherman Titov, Andrian Nikolayev, Pavel Popovich, Valery Bykovsky, Valentina Tereshkova, and Pavel Belyayev and Alexei Leonov. Includes two duplicate covers. In fine condition. Pre-certified Scott Cornish and RR Auction COA.