Worst uncontrolled spin

The US Gemini 8 mission was flown by Neil Armstrong and David Scott (both USA) on 16–17 March 1968. It achieved the first docking in space, between Gemini 8 and an unmanned Agena booster. While docked, the combined spacecraft began an uncontrolled roll. After an emergency undocking, Gemini 8 began to roll faster, approaching one revolution per second, and the crew were dangerously close to g-forces that would have impaired their vision or caused them to black out. Armstrong was able to stop the roll using the re-entry thrusters on Gemini 8 and initiated a mission abort and safe emergency splashdown.