The hard part is keeping track of all the political developments that occur on planets between visits. You have to assume some power source other than fusion to make it realistic.
Since Traveller has grav tech, how about a singuarity drive? This traveller setting has everything the OTU has except a jump drive, including the ability to control gravity within the ship. If it has this ability, you place a tiny black hole in the center of the reaction chamber. Gravity control keeps the black hole centered regardless of the acceleration the ship under goes. Hawking radiation from that tiny black hole is what powers all the ship's systems, including maneuver drive, weapons etc. When the ship fuels up, it dips into the atmosphere of a gas giant and feeds its black hole until it accumulates many times the ship's "dry mass", this means that most of the ship's loaded mass is in that tiny atom-sized black hole and everything else is only a tiny percentage of the ships over all weight. I'm also assuming there is no magical reactionless maneuver drive, instead what we have is something like a pion drive where charge particles and antiparticles evaporate from the black hole as Hawking radiation, and the larger particles annhilate in a matter/antimatter reaction producing short lived pions which are funneled out of a magnetic nozzil at the back of the ship, it this way, the black hole's mass gets converted into energy. the black hole is just a convenient way to make a rocket without obscenely huge tanks. The black hole also eliminates the need to store tons and tons of antimatter and matter that would take up most of the volume of the ship along with the containiment systems.
A ship with a black hole or black holes whose total mass was 100 times the dry weight of the rest of the ship could reach a final velocity of 0.9998 c assuming total mass to energy convesion and 100% efficent channeling of the Hawking radiation out the back nossil. Of course 100% efficientcy would not likely be achieved. the formula for final velocity as a percentage of the speed of light is:
V/c = (R^(2 * square root(e * (2 - e))) - 1) / (R^(2 * square root (e * (2 - e))) + 1)
Where V is the final velocity,
c is the velocity of light,
e is the fractional conversion of mass into energy,
and R is the mass ratio of loaded mass to empty mass,
^ is the exponent symbol that I use and * is multiplication.
In the case of a singularity drive, the back hole converts itself into energy with 100% effeciency producing approximately equal amounts of matter and anti matter as well as photons from its event horizon, chanelling that energy with 100% efficiency is another question, so you might assume 50% effeciency as a conservative estimate.
That sounds intriguing and now I want to read this guy's theory. Argh! I need his name!
