John Snead
SOC-6
Several things have always troubled me about Traveller thruster plates. The most obvious problem is that (depending upon the exact rule system) most versions of Traveller have either thrusters or power plants sucking down simply ludicrious quantities of hydrogen for what is allegedly a fusion plant generating electricity to power a reactionless drive. Then, there are the various issues with reactionless drives themselves (including how easy it is to weaponize them).
One idea that I've always liked is to change Thrusters into reaction drives, but of a very particular (and highly efficient) sort - make them a total conversion drive that converts hydrogen into a directed beam of neutrinos - I'd make this technology related to nuclear dampers. Neutrinos are good both because the drive exhaust is not particularly visible (good for stealth) and because its harmless, allowing ships to land or dock at space stations w/o incinerating their surroundings. Running the numbers, the results also look pretty darn close to the actual figures for how must hydrogen power plants or manuever drives use. Using a loaded mass of 680 tons for a 100 DTon Scout/Courier (from TNE, and a good intermediate figure between the 916 ton mass of a a 100 DTon MT Scout and the 350 ton mass of a 100 DTon GT Scout ) & throwing the rocket equation at it
ln (ML / MB) = CB / Isp*g
ML is the launch mass, MB is the all-burnt mass, CB is the rocket velocity in metres per second at all burnt, Isp is the specific impulse in seconds and g is the acceleration due to gravity at launch in metres per second per second.
Using this, 1 ton of hydrogen accelerates the ship to a velocity of 430 km/hour, which works out to 12.25 G-hours. So, a not unreasonable 8 tons of fuel works out to 98 G-hours, which is sufficient for any remotely reasonable purpose (allowing for a 12% fuel reserve and deceleration, this gets you from Earth to Jupiter in less than a week).
While I'm at it, I'd also modify contragravity a bit too. In my idea, contragravity (aka antigravity) can be used for both lift and propulsion, but decreases in power with the inverse square law (just like normal gravity). A 6 G contragravity drive remains the most powerful gravity drive possible to build, and at 100 diameters from a 1 G world like Earth, this drive would generate a thrust of 0.0006 Gs, which nicely limits antigravity w/o making it useless.
So, for landing and take-off, ships use contragravity, while for in system travel they use neutrino thrusters.
Thoughts?
One idea that I've always liked is to change Thrusters into reaction drives, but of a very particular (and highly efficient) sort - make them a total conversion drive that converts hydrogen into a directed beam of neutrinos - I'd make this technology related to nuclear dampers. Neutrinos are good both because the drive exhaust is not particularly visible (good for stealth) and because its harmless, allowing ships to land or dock at space stations w/o incinerating their surroundings. Running the numbers, the results also look pretty darn close to the actual figures for how must hydrogen power plants or manuever drives use. Using a loaded mass of 680 tons for a 100 DTon Scout/Courier (from TNE, and a good intermediate figure between the 916 ton mass of a a 100 DTon MT Scout and the 350 ton mass of a 100 DTon GT Scout ) & throwing the rocket equation at it
ln (ML / MB) = CB / Isp*g
ML is the launch mass, MB is the all-burnt mass, CB is the rocket velocity in metres per second at all burnt, Isp is the specific impulse in seconds and g is the acceleration due to gravity at launch in metres per second per second.
Using this, 1 ton of hydrogen accelerates the ship to a velocity of 430 km/hour, which works out to 12.25 G-hours. So, a not unreasonable 8 tons of fuel works out to 98 G-hours, which is sufficient for any remotely reasonable purpose (allowing for a 12% fuel reserve and deceleration, this gets you from Earth to Jupiter in less than a week).
While I'm at it, I'd also modify contragravity a bit too. In my idea, contragravity (aka antigravity) can be used for both lift and propulsion, but decreases in power with the inverse square law (just like normal gravity). A 6 G contragravity drive remains the most powerful gravity drive possible to build, and at 100 diameters from a 1 G world like Earth, this drive would generate a thrust of 0.0006 Gs, which nicely limits antigravity w/o making it useless.
So, for landing and take-off, ships use contragravity, while for in system travel they use neutrino thrusters.
Thoughts?