News briefing for John Glenn's Mercury-Atlas 6 mission with image of the Friendship 7 spacecraft's orbital flight in background. The trajectory was controlled by computers, but Glenn asked engineers to get NASA research mathematician Katherine Johnson to check the orbital equations by hand on her desktop mechanical calculating machine.
News briefing for John Glenn’s Mercury-Atlas 6 mission with image of the Friendship 7 spacecraft’s orbital flight in background. The trajectory was controlled by computers but, as part of the preflight checklist, Glenn asked engineers to get NASA research mathematician Katherine Johnson to check the orbital equations by hand on her desktop mechanical calculating machine.
Image Credit: NASA