Humans are the most flexible and reconfigurable system for assembly. They can identify and deal with near infinite variations in position and condition of your inputs. If you look at automated assembly like 3/4 of the automation is to make sure the robot has the pieces is in the right place or orientation and the movements that are used are not complicated. Meanwhile for a human you can toss a bag of parts and they'll just fish through the bag or reoriented whatever as needed. Put a piece sideways into a machine that wasn't made to deal with it and it'll just flip out. Also reconfiguring assembly lines on the fly is feasible, change what the line is doing could be as easy as workers grabbing a different tool box. Fixed assembly lines are only good at scale and if the product will change incredibly slowly.
Elon has always been one of the main drivers of innovation over there, Gwenn has been the one keeping stuff afloat but Elon has been the one driving the "the hell I'm paying that much for a piece, I'll make it myself" culture as well as the iterative process.
I'd imagine a lot of places where software is part of a safety critical system also come with physical fail safes. An example being burst plates on pressure vessels, if the software that controls pressurization spasms and causes an over pressure the physical fail safe will prevent a catastrophic accident.
Rock isn't necessarily airtight more so in mines. A fractured host material for the ore is very desirable as it means less explosives and higher ore production numbers.
It's not like the engine start procedure on one of those things is a turnkey solution. The amount of domain knowledge needed serves as a form of soft security.
The checklist is what you'd be reading, usually a laminated one-page card kept in a convenient spot. The documentation that the checklist refers to is the full "user manual" for the plane, with things like the quick reference handbook (QRH) that includes the step-by-step procedures covering what to do for every single warning light, emergency condition, etc. Also "documentation" here could also cover the mandatory things you have to have in the plane like the airworthiness certificate, registration, FCC radio license, insurance certificate, etc.
So I guess the short answer to your question is yes, in this context the documentation and checklist are not the same thing.
Right but my point is if you're premeditating the theft to the point where you've studied the manuals/practiced in flight simulators then a key isn't going to be the thing stopping you. I mean will that person realistically go "oh man, I've spent 100 hours learning how to pilot this thing, snuck into the plane, properly fueled the plane and did weight balancing but shit I don't have the keys, guess I'll just go home!". Nah, that guy is hot wiring that plane or stealing the keys on his way into the plane.
Atmospheric concentrations are low so you need to harvest a lot of air. To put in context the earth has ~2E9 km^3 air, if you wanted to process every cubic meter of air in the world once in 10 years you'd have a system that could process ~6km^3/s , using air flowing at 30kph(18mph) would require ~800km^2 of collecting area.
Not an issue if you have low abandonment of subscribers but an issue if everyone exchanges papers that way. You get a lot of value out of being able to search all the journals in one place. Also what happens if the author is dead or has dropped off the face of the planet.
