It's untouched ground, there's a minimum threshold for being a self replicator, but no minimum threshold for getting called 'operating system' (I myself can probably write an 'operating system' in a week or two, or even in a weekend, depending to how little we consider to be an operating system), and such replicator - I am speaking of supervised self replicator, i.e. largely under remote control - is economically ineffective compared to regular, staffed factory. A replicator is no magic - it is a moderately big complex of factories, with automatization of even the rare tasks that would normally be much much cheaper to perform with humans - there is literally no commercial incentive to design something like that, considering that it would cost billions to design. More, actually, because the hardware of the first original is going to be awfully expensive.
I must make clear what replicator I am speaking of. A practical one, which is to significant extent remotely controlled, and for which much of the difficult to manufacture electronic components (CPUs, memory chips) are shipped from Earth (they are lightweight). Such replicator would require multiple extremely heavy launches to get there, it would be very fragile, and it would grow considerably slower than even remotely wise investments. So you'll probably be better off simply doing something else and going to moon later.
It is not really glamorous awesomeness by any means. It would largely rely on existing CNC machines and existing robotics, it would be huge, it would be messy, and it is going to break down once in a while at first (with a bit of luck that may be resolvable with remotely controlled robot, in a manner similar to trying to solder chips onto a board by holding them with chopsticks).
edit: tl;dr; it can be done, it wouldn't be the most complex task mankind ever done, and it is going to suck.
I am calling you out -- I don't think you can write an operating system from scratch in less than a few years. (I thought tinkering in an existing toy OS for a semester in my undergrad OS class was fairly hard. I once tried writing a "real" file system from scratch -- very difficult also).
How familiar are you with software engineering or mechanical engineering? You are systematically underestimating the difficulty of engineering tasks, I think. You sound like a futurist, not an engineer.
I am not sure I understand the concrete proposal you a...
This article http://www.huffingtonpost.com/andrew-kessler/why-you-should-be-more-interested-in-mars-than-the-olympics_b_1712462.html -- ok, I admit, I read Slashdot sometimes, no one is perfect ;) -- made me wonder why the awesomeness of space conquest stopped motivating people.
I remember the tales of my parents at the time of the Apollo landing, it was indeed instilling awe and wonder in the minds of people. It was followed by people like the Olympics or the football competitions are. And nowadays, NASA about to send a nuclear-powered rover to Mars, in a very delicate mission requiring the best of human engineering and scientific skills, and not in line in most media, most people not even aware of it? How did we fall that low?
Sure there was the Cold War. It definitely played a role, in the amount of resources invested by both sides in space conquest, and in the way the media broadcasted the news.
But here in France, a country that was mostly neutral during the Cold War (slightly west-aligned, but not part of NATO for most of the Cold War), the interest of people for space was not really partisan. People who were pro-USSR were amazed and cheering for the Appolo mission, people who were pro-USA were amazed and cheering for Gagarin. My brother and I played with (USSR) Sputnik as much as with (USA) space shuttles. We praised equally Neil Armstrong and Yuri Gagarin. I don't think the lack of Cold War explains it all.
So what happened to the space conquest spirit? How did it disappear? I notice a blank spot on my map (well, not totally blank, but still very fuzzy) of reality, do some of you have clues for how to fill it?