Choosing 4E Spaceship Propulsion

[Seneschal]

Originally Posted by dynaman

Consider making it hyperspace like in Babylon-5. They had hyperspace where ships moved at the same speed but things were much closer together, I think, JMS never really did specify more then needed (ships moved at the speed of plot - but you can make them move more consistantly).

Then add in Hyperspace storms (watch an episode of B5, just think of Hyperspace as having storms, not hard to visualize), so going through will take longer.

Finally add in Fold Faults from Macross Frontier, normally a fold (warp, jump, etc..) takes X time for Y distance, but going through a fault takes MUCH longer, weeks instead of days for instance.

Finally finally, do not try to pin it down, just say that hyperspace exists, that there are storms and faults, both come and go according to the following observed pattern (whatever pattern suits your needs) but that the big heads in the science fields can't explain WHY it works - only how...

Hmmm, I know of Macross Frontier and Babylon 5, but I must admit I haven't seen them yet (and everyone always looks at me suspiciously when I admit that), but I'm sure they have wikia sites where the fans collected technical details.

You're right, I'll let stardrive go unexplained, or just say "quantum this, quantum that", as it's merely a convenience and a necessity of the genre (and you don't need to travel through hyperspace in everyday life). However, more palpable elements like sublight engines and nanofabrication are a bit trickier, since they change the way society looks like from the ground-up.

I like the idea of faults, it gives a strategic dimension to interstellar space. When I was thinking of a jump drive, I discovered that it made star systems more connected to each other than to the individual planets inside those systems, and interstellar distance practically stopped being relevant. I think I'll stick to some sort of hyperdrive, since I don't want a voyage to the nearest system and an enemy's homeworld 500 parsecs away to take the same amount of time/effort.

EDIT:

Originally Posted by johndallman

The traditional ways of solving this problem are:

Pick a technology, on the basis of what you find appealing and/or plausible, elaborate it a bit for the sake of realistic variations, and then let it shape your plots.

Sketch out some plots, select technologies and constraints to fit them, and then proceed as above.

Do you have any particular model you're trying to emulate? A few that your write-up reminds me of are: the Lensman series (correct starting point for this is First Lensman), the Honor Harrington series (On Basilisk Station) and The Culture (Consider Phlebas). You clearly want something more rational than Star Trek or Star Wars, so prose fiction is likely to be the best model.

I've read all of the above, and I think the Honorverse is a good match in aesthetic feel (I initially had the idea of ships with sail-like propulsion ramming each other, but I thought it was a bit too fanciful), but The Culture is closer in terms of technological development (i.e. advanced enough tech to create unrecognisable, immortal, transhuman cultures with few limits and worries), although I backed off from TL12 humanity for fear that the players wouldn't have anything to associate to, or that there wouldn't be tension.

Speaking of the Lensman, I had the idea of making all the ships inertialess. It would prevent the whole "civilian spaceship propulsion = weapons of mass destruction" (e.g. ships would be forbidden from accumulating enough kinetic energy to cause significant damage in the vicinity of a planet/station) and give a good reason for there to be a lot of civilian and corporate ships flying around. Plus, if they can decelerate instantly, it cuts travel time by about 1-3 days on interplanetary distances (1-10 AU), giving me space to use more realistic reaction engines. However, the implications are a bit unclear to me, since I'm no physicist - if hit with a kinetic projectile (missile, gun, gauss), would the ship loose all of its (pseudo) velocity? If so, what would happen if a laser hit them? How would they react to atmospheric reentry (GURPS Spaceships says an inertialess object is merely stopped in place by a collision, and suffers no damage)?