> I doubt you could easily get things like rope core memory or just about any of the components.
"Any of the components" is an exaggeration. For example, bipolar transistors are still here, here's the schematics [0] of the switched-mode power supply in the AGC - still perfectly understandable, rebuilding it can a fun weekend project. Also, discrete NOR gates are still around, although the underlying technology is different.
> As with many things, you can't easily replicate complex old artifacts because you don't even have the tools to make the tools to make the tools... No, we couldn't build an Apollo Guidance Computer today.
I think there's a difference between a 1:1 faithful replication and a replication based on the same architecture and/or principle of operation. While it's difficult to build a 1:1 faithful replication, rebuilding a new one based on the same architecture in general is much easier.
So when the original commenter said, "no one understands how the engines on the Saturn V work anymore", I think the point to be made is whether the ideas from the Space Age, e.g. whether the Saturn V architecture has survived, it is not necessarily meant that rebuilding it makes sense - it probably does not.
> The guidance computer would probably be the least of your challenges
We understand very well the basic approach that was taken to land on the moon and the hardware we used to do so. We'd have to re-engineer a lot of things that aren't just off-the-shelf to do it again. But we could do so pretty quickly if there were any compelling reason to do so.
As I understand it, current technologies that could include moon landing are being worked on in the broader context of going to Mars.
> We'd have to re-engineer a lot of things that aren't just off-the-shelf to do it again.
Yes. I think this is the perspective that people trend to overlook - every engineering project is unique, in the sense that it's optimized to do the job under very specific constraints - costs, production capabilities, available materials, etc. When the circumstance changes, sometimes you simply can't just pull the same blueprint out of the archive to make another one - redesigning it is sometimes unavoidable, even if the older design is nothing wrong from a technical point-of-view. I think the same applies to software development.
"Any of the components" is an exaggeration. For example, bipolar transistors are still here, here's the schematics [0] of the switched-mode power supply in the AGC - still perfectly understandable, rebuilding it can a fun weekend project. Also, discrete NOR gates are still around, although the underlying technology is different.
> As with many things, you can't easily replicate complex old artifacts because you don't even have the tools to make the tools to make the tools... No, we couldn't build an Apollo Guidance Computer today.
I think there's a difference between a 1:1 faithful replication and a replication based on the same architecture and/or principle of operation. While it's difficult to build a 1:1 faithful replication, rebuilding a new one based on the same architecture in general is much easier.
So when the original commenter said, "no one understands how the engines on the Saturn V work anymore", I think the point to be made is whether the ideas from the Space Age, e.g. whether the Saturn V architecture has survived, it is not necessarily meant that rebuilding it makes sense - it probably does not.
> The guidance computer would probably be the least of your challenges
+1.
[0] https://www.righto.com/2019/08/reliable-after-50-years-apoll...