the splatters of blood on the checklist for the very first us spacewalk were from an astronaut as he frantically battled to close the hatch door of the spacecraft after a historic venture .
but the gemini 4 mission of june 1965 ultimately proved successfully , and paved the way to astronauts walking on the moon for the first time four years later .
gemini 4 launched from cape canaveral in florida on 3 june 1965 with two astronauts on board .