Building a new 1969 Mustang from scratch today would be a pretty large undertaking.
Yes, but in this case there are still a lot of 1969 Mustangs on the road. It's not a good example because it's not truly a dead design. There are still machinists and fabricators who can make new parts, and some of the manufactured components (e.g., oil filters) are still available because there's enough market to have retained manufacturing capacity. But the question subtly shifted to "Build a 1969 Mustang as a one-off." It was originally, "Have Ford build you a new 1969 Mustang." The whole point was that they would have to do it as a one-off -- at great and uncommon expense and effort. The only reason to do it would be to have a nostalgic car, whatever the cost. That's not the same proposition as, "Give me a colon-rumbling muscle car." Jr Knowing is equivocating around, "They had 'the technology' back then, so why not now." This is why he refuses to specify "the technology."
Not only are their factories not setup to build that car, all of the people who were involved in building it 50 years ago have long since retired or died. Machines aren't just built from blueprints, they are built from the knowledge and experience of the people building them. When those people are gone much of their knowledge goes with them.
This is supremely important in aerospace. Paradoxically, some parts of the LM had to be hand-build and hand-assembled, and other parts could not be hand-built. Grumman's proprietary method of chemical milling was used to produce the parts of the pressure vessel with their integrated stringers. That's not a hand process. You need all the infrastructure. It's not something you buy at the hardware store. It's stuff that Grumman literally invented, and ever only existed in their plants. And you had to have the people who operated it. It's not something you can read in a manual or learn at the community college because, again, Grumman literally invented it and the only people who ever knew how to make it work were the people at Grumman. One of my customers has a need to wrap large containers with Kevlar fibers. The machine that does this is literally the only machine in the world that can do it. They invented it, designed it, and built it. And the guy who designed it is the guy who operates it. While he has trained others, he is still the guy who has to be called in to diagnose and fix the problems with it. Getting back to Grumman, the chem-milling process they developed was superseded first by improvements in five-axis machining, and later by additive manufacturing. "They had the technology back then" doesn't mean they still have it, need it, or use it today. And the harsh realities of aerospace manufacturing mean that you don't waste the space keeping around obsolete tools for obsolete processes. The LM pressure vessel panels were designed knowing they'd be manufactured using that process. For at least some of those panels, additive machine could reproduce the shape, but not necessarily all the structural properties that were needed. That is, you can't assume a metal part built up additively will have the same structural strength as the equivalent shape created by subtractive methods. This is, in fact, why we machine parts for aerospace that would be created by shaping or forging processes in other industries where weight is less a premium.
Frank Pullo tells of problems in the ascent-stage fit-up. They had plywood fixtures and so forth that would keep the components aligned, but none of those setups would fit into Grumman's automatic welding and drilling machines. This was especially a problem around the struts for the propellant tanks, which interfered with the fit of the pressure-vessel panels to the structural framing. By the time you got everything aligned properly, there was no way to get the automatic fastening machines in there. So the assembly line workers just did it by hand,
because they were that good. There were, at the time, people who could drill a hole with a hand drill to a tolerance of just a few mils from where it needed to be. That's not to say such skill doesn't exist today. But it's to say that the design of the machine depended very much on the idiosyncratic capabilities of who was going to make it.
Likewise, the Apollo rockets and spacecraft etc. are not just blueprints. They are the works of people who are no longer around. Knowledge has been lost, so any attempts to recreate Apollo will involve re-learning how to do things.
Yes. Conspiracy theorists, none of whom has been within ten miles of an actual aerospace project, seem to think they can simply remove the human element from the design and manufacturing process. This is not how aerospace works. It's not how it has ever worked. There is no set of documents that would ever fully capture the expertise of building something.
Can it be done? Sure, but it won't be easy.
Or cheap, or ultimately effective. Yes, some clever engineering firm could figure out how to manufacture, via some new process, the panels that Grumman chem-milled. Or some other clever firm could spend years re-inventing Grumman's chem-milling processes, possibly with the help of ex-Grummans who haven't passed on. But it would not be a shortcut to success today. And that's the claim. It should be easier now, they say, because we did all the hard work decades ago. They don't understand the whole process of high-stakes engineering and manufacture.
We have Apollo hardware in museums that could be torn down and reverse engineered if we absolutely had to rely on them to regain that knowledge.
I think Adam Savage and his colleagues just rebuilt the CM door. I got to play with a Block II CM door last month, in California. I've always appreciated some of the ingenious elements of that mechanism. The Orion capsule hatch works according to the same basic mechanical principles, but has additional constraints for usability and safety that weren't required for Apollo. So while the Apollo side hatch informs the design, it doesn't provide the design. The adaptation is still a new design.
Similarly I watched people consulting the Apollo LES design documents to inform the design of Orion LES. The "blueprints" (nitpick: Apollo drawings were reproduced using the diazo process) were life-size drawings of the assemblies, tacked up on the walls of the bullpen. They extended floor to ceiling and were several meters long. This is not the sort of thing you can Google for. But it exists, and it can be consulted.
