This one has been going around the aviation centric blogs. Modern aircraft are almost unbelievably complex. While modern airliners have excellent reliability, they still need to be overhauled regularly. British television takes an hour long look at just how in depth these overhauls are. Get the coffee pot going, grab the comfy chair, and settle in. It’s well worth the hour.
And if you think airliners are complex, you should imagine the spacecraft Roamy works on. They face an environment that is orders of magnitude more hostile, and have far, far less space and weight available to address challenges.