The Way to the Moon
On July 11, 1962, NASA announced a decision it had been wrestling with for years. They had finally concluded the best way for Apollo to deliver astronauts to the lunar surface was through a Lunar Orbit Rendezvous (LOR). Essentially, the Apollo CSM and the Lunar Module would travel together to the Moon, and the Lunar Module would land, return to orbit and dock with the Apollo CSM before returning home.
The concept had first been proposed in 1919 by a Soviet engineer, but there were other options that were also on the table: Direct Ascent and Earth Orbit Rendezvous.
Direct Ascent was the early favorite. It involves launching a spacecraft from Earth directly to the Moon, where the entire vehicle would land, ascend, and return to Earth. This was the method used to send the Surveyor probes to land on the moon between 1966 and 1968. But the Surveyors didn’t have to lift off and return to earth, and they weighed 306 kilograms (675 pounds) at most on landing. The Apollo CSM, when sent to the Moon, weighed ninety-four times that. If it had been designed to land on the moon, it would have been far larger and heavier to account for the extra fuel necessary and added equipment like landing legs. NASA estimated this type of spacecraft would have weighed more than 45,000kg (100,000 pounds). To lift something that heavy out of Earth’s gravity, NASA would have been forced to use a Nova rocket or the proposed Saturn C-8.
The Earth Orbit Rendezvous method would have required multiple launches to put the various elements of the lunar vehicle into orbit, assemble and possible fuel them there, before sending the completed spacecraft to the moon. The only advantage here would have been the launch boosters could have been the smaller Saturn I.
There was a fierce debate over the issue. One issue was the idea of a lunar lander having to rendezvous with the spacecraft in lunar orbit before returning home. At this early point in the space program, no one was absolutely sure rendezvous could be accomplished safely. But John Houbolt, an engineer at the Langley Research Center and a member of the Lunar Mission Steering Group, led a vigorous campaign in favor of LOR. In November of 1961, he went over the chain of command and wrote directly to NASA Associate Administrator Robert Seamans. "Do we want to go to the Moon or not?" he wrote. "Why is Nova, with its ponderous size simply just accepted, and why is a much less grandiose scheme involving rendezvous ostracized or put on the defensive?”
Seamans assured him LOR would be given full consideration. And over the next seven months, Houbolt and other LOR advocates won over the Space Task Group and von Braun’s team at the Marshall Space Flight Center. They were able to convince NASA Administrator James Webb.
One argument in LOR’s favor was that with two spacecraft, there would be duplicate life-support systems. That would come in handy on April 13th, 1970, as we shall see.
With the decision made, NASA could move forward with finalizing the design of the Apollo CSM and the creation of a lunar lander. Within days of the July 11th announcement, NASA invited eleven companies to submit proposals to build the Lunar Module. Nine responded. In September, Grumman was awarded the contract.