Tang is a farce. That was the first thing Neil Armstrong told me last night. “We did not use it on the Apollo missions.”
I asked him, of all of the systems and stages of the mission, which did he worry about the most? (the frequently failing autopilot? the reliance on a global network of astronomers to spot solar flares in time to get the warning out? the onboard computers being less powerful than a Furby?....)
No, none of those. He dove into a detailed description of the hypergolic fuel mixing system for the lunar module. Rather than an ignition system, they had two substances that would ignite upon contact. Instead of electric valves, he wished he had a big simple mechanical lever to open the valves. He kept using his hands to show how easy a big lever could be.
That seemed a bit odd to me at first. So, I asked if he gave that answer because it really was the most likely point of failure, or because it symbolizes a vivid nightmare – having completed the moon mission, pushing the button... and the engines just wont start.
He responded that he had dreams about that for two years prior to the launch.