Re: (1909) Maneuver drives

Leonard Erickson writes:

>No, reaction drives will work just fine. It's just that some people
>hear "reaction drive" and think of our current *chemical* rockets. A
>fusion rocket uses 1/1500 of the fuel. So they *do have reasonable fuel
>requirements, and endurance. I checked the original rules, and a type-S
>scout would *still* be able to run it's manuever drive at full throttle
>for a week if you assume it is a fusion rocket! Or ships should have
>similar endurances.

Wrong.  I don't have the mass for a scout handy, but it was close to
1 ton per kl = ~1350 tons for the whole ship.  2 G's for a week gives
a net velocity change of  ~12,000 km/sec.  Using the speed of light as an
upper bound for the exhaust velocity we get a minimum mass fraction
of 4% just for reaction mass (totally ignoing energy requirements).  This
gives 54 tons mass needed.  The scout had 20 disp tons of LH2 for the
powerplant and manuver drives = 20 tons mass - not enough.  Check
your math before making specific claims.

					W. Dow Rieder

 	When the only tool you have is a hammer, all your problems
start to look like nails...