Powered Descent Initiation
Powered Descent Initiation (PDI)is a term used during theApollo programMoon landingmissions to describe the maneuver of theApollo Lunar Moduleas it descended fromlunar orbitto arocket-powered landing.[1]
"Eaglewas GO to ignite its descent engine, andArmstrongandAldrinlocked their eyes to the glowing numbers displayed before them. They were almost at an invisible junction of height, speed, range, and time when everything would join together for commitment. When the instruments told them that they were 192 miles from their projected landing site, and were precisely 50,174 radar~measured feet above the long shadows of the moon, they would unleash decelerating thrust and begin slowing their speed for the touchdown.....this was it. PDI. Powered Descent Initiate. "[2]
References
[edit]- ^A Running Start - Apollo 17 up to Powered Descent Initiation
- ^Moon Shot The Inside Story of America's Race to the Moon, Alan Shepard/Deke Slayton Page 17 First Edition