On 21 Jan 2018 at 4:35, 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. Thing is, at the velocities Traveller ships *routinely* achieve, they are weapons of mass destruction. That means that except around "frontier" worlds there *will* be Space Traffic Control (STC), and they will get *very* particular about orbits. Basically, you arrive at the 100 diameter limit, contact STC, and they will *assign* you an approach trajectory that either leads to an assigned parking orbit or to a land patternn (where you get handed off to the local ATC whic controls everything from "low orbit" to ther ground. Any powered manuevers will be required to mmeet two criteria. First, that if you keep going at that acceleration vector you won't come too near anything else. Second that if you lose power (or drop something) that vector won't come near anything important. Failure to obey is going to be considered a *very* hostile act. And will get you fired upon. Failure to contact STC will get you intercepted or possibly fired upon. Given that a runaway ship can *easily* cause nuclear level events, this is not at all unreasonable. BTW, if you are going to dock at an orbital station, you'll get assifgned a trajectory to get "close" to it, such that you wind up at rerst relative to it at some safe distance. Then docking control will talk you in. ps. for dealing with planetary orbits and the like, just steall an idea from the old "Battlefleet Mars" game. They had "orbital tracks" for the planets and you moved a counter one space along the track for every day (or week for the outer planets) of game time. If you are using computer support, just use orbital period data for the planets, and pick some point in the past where all of them were at a starting point (say, the most coreward part of their orbit). Then the computer can just run that forward to determine the positions when the players visit. Given that interplanetary travel is pretty much "point and shoot" with multi gee constant acceleration drives, all you need to do is figure out the positions to get the distance, which won't change significantly during the trip. -- Leonard Erickson (aka shadow) shadow at shadowgard dot com