NASA space-flown Gemini and Apollo medallions

NASA space-flown Gemini and Apollo medallions were mission-specific commemorative medallions, often astronaut-designed, which were approved by NASA and carried aboard the mission spacecraft into orbit. Beginning with the first crewed Gemini mission in 1965, commemorative medallions were prepared for the astronauts at their request.

Source: Wikipedia — NASA space-flown Gemini and Apollo medallions (CC BY-SA 4.0)