...However, I remember being puzzled at the time as Frontier said that an offline version that had been a feature of the KickStarter wasn't possible.
Well DB didn’t actually say it wasn’t possible, just that it wouldn’t meet their vision for a living, breathing Galaxy.
I forget the exact wording, but it was a design decision not a technical one.
Edit: from the Newsletter: “A fully offline experience would be unacceptably limited and static compared to the dynamic, ever unfolding experience we are delivering.”
A further statement by M. Brookes - “The problem is that the galaxy mechanics all sit on the online servers...The data set and processes are huge and not something that would translate offline without considerable compromise to the vision.”