Ask HN: What's an astronomical architecture?

I see the term 'architecture astronaut' used a fair bit and I'm wondering if people can point out some examples of what kinds of architecture these astronauts design. Mainly because I want to write better factored code myself, without becoming an astronaut :)

My gut instinct is that over-engineering and astronaut architectures are mostly related but somewhat different in spirit; over-engineering comes from trying to make a solution that targets the wrong type of generality (trying to design for predicted needs that never materialize) while astronaut architecture is something that happens when the architecture becomes an end in itself rather than something created because ultimately there's a problem to be solved.

I don't even know if what I said makes sense....

So, what are some examples of 'astronaut architectures' that you've seen and what set them apart as astronaut architectures vs just highly complex systems?