On 21Jan2018 2235, Caleuche wrote: > I was going to mention that, or ask about it. As far as I can tell, > there's no reason that everyone shouldn't be using powered orbits, is > there? All traveler spacecraft (prior to T5 at least) could minimally > maintain 1g acceleration for 30 days which removes the need for orbits > at all. I'd imagine space stations need not be in orbit either. In fact, > around asteroids and planetoids, the space station operator would have > to be careful as an object in a powered orbit like that is effectively a > gravitational tractor, and will change the orbit of the planetoid around > its primary star over a long enough period of time. I assume that most objects, unless there's a clear need for them to be in a powered orbit, aren't. The reasons are tradition, 'safety' (i.e. a largely irrational belief that unpowered objects are less likely to collide with something), and ease of management - put something in an unpowered orbit and it's easy to find later. -- Rupert Boleyn <xxxxxx@gmail.com> Chief Assistant to the Assistant Chief