...Jeez - I have to say, again as a novice(!), based on this transcription I can't help concluding that the LM landing was a massively high risk proposition. How on earth (or should a say 'moon'!) did they all get themselves comfortable with the seemingly less-than-remote possibility of catastrophic consequences of encountering an obstacle or highly unfavourable terrain?!
Good question.
First, nobody was "comfortable" with it. The mission was risky. Epic journeys usually are. The only way to avoid the risk was to decline the challenge of going in the first place.
However, the risk could be, and was, minimized in a variety of ways.
The landing site was imaged by Earthbound and orbiting instruments. The lunar surface and environment were characterized by robotic probes, both soft landers (Surveyor) and impactors (Ranger). The general space environment, including the behavior of the Sun, was studied by dozens of probes and a wide assortment of ground-based instruments.
The technology was made as robust and reliable as possible. The LM power and propulsion systems were kept simple - avoiding fancy fuel cells and pumps. There was a completely separate Abort Guidance System computer which could bring the LM crew back to the CSM at just about any point- their equivalent of a "zero-zero" ejection seat. You get the idea.
Everything was tested extensively, at the component, subsystem, and system level. I've participated in thermal/vacuum spacecraft tests in Chamber B at JSC, where the LM was tested, right next to the mammoth Chamber A where the CSM stack was tested. Then the vehicles were tested in flight - in Earth orbit, in lunar orbit, and a final descent and ascent profile of the LM on Apollo 10. Apollo 11 can be regarded as the final Apollo test flight. It had one primary objective: to land men on the Moon and return.
The crews received an enormous amount of multimodal training, including flying dynamics simulators like the LLRV/LLTV and a variety of systems and visual trainers which simulated the look of the approach in various ways.
The final and most important element was that of the men flying the mission. Like most of the pre-Skylab astronauts, all three were experienced military pilots. Collins was a test pilot. The LM crew in particular might be equalled, but not exceeded, in its qualifications. Both Armstrong and Aldrin were jet combat veterans. Armstrong was a test pilot who had flown the X-15, and Aldrin held a PhD in astronautics. Both had flown on Gemini. They had the skill, the experience, the nerve, and the training for the job, including the ability to recognize and react to any imaginable contingency, modifying the landing as necessary (and as actually happened).
For all this, though, the result of on the order of a million man-years of effort from some four hundred thousand participants, what was accepted was that the endeavor was still a
risk. That is why President Nixon had ready, in addition to a triumphal celebratory speech, a much shorter somber one for use if they had perished in the attempt.
