On this date 50 years ago, NASA launched three astronauts into space. Four days later, two of them would make history by becoming the first Earthlings to set foot on the moon. What may be one of mankind’s greatest technical achievements was a technological marvel that came to be called the Saturn V rocket.
If not for Langley-based NASA engineer John Houbolt, getting to the moon before the end of the 1960s might have been a no-starter.
Souce: NASA
The original plan was for astronauts to blast off in a giant rocket and back that rocket down onto the lunar surface. NASA called this direct ascent.
The plan seemed simple enough, but required a lot of brute force. Houbolt did the math and found the amount of fuel required to lift a giant rocket off the Earth and then again off the moon would have been enormous. He proposed a better way.
After the astronauts finished their work on the moon, the rocket would blast off again and head back to Earth.
With lunar orbit rendezvous, or LOR, NASA would launch a spacecraft designed in small modules and then discard the used modules as they go.
A landing module would carry two astronauts to the surface while one remained behind in orbit with the main spacecraft.