CNN Films’ “Apollo 11” explores the exhilaration of humanity’s first landing on the moon through newly discovered and restored archival footage. Watch the TV premiere of this documentary Sunday, June 23, at 9 p.m. ET/PT.

CNN  — 

During the 1966 Gemini 8 mission, commanded by astronaut Neil Armstrong, an error caused the spacecraft to spin so violently that his and astronaut David Scott’s vision blurred.

It was set to be the first space docking in history between two spacecraft, Gemini 8 and the Agena, during NASA’s second human spaceflight program.

The astronauts were stuck in a loop, spinning faster and faster. “We have serious problems here,” Scott told Mission Control. “We’re tumbling end over end. We’re disengaged from the Agena.”