10 Leva Space Exploration

Issued to mark the joint Soviet-Bulgarian Soyuz 33 mission of April 1979, which ended in an abort after the main engine failed during the docking approach to Salyut 6. Cosmonaut Georgi Ivanov became Bulgaria's first man in space, though the mission never achieved its intended docking — the crew returned safely on the backup engine after a harrowing re-entry.

The .900 silver variant, KM#105a, was struck alongside a cupro-nickel circulation issue. Bulgaria produced several denominations commemorating Ivanov's flight, making this part of a broader state campaign to extract prestige from a mission that, technically, failed its primary objective.