FF&S: Broken Daedalus Drive?

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[email removed] (Steven M Bonneville) wrote:

>Recently, for whatever reason, I looked into designing a ship capable
>of interstellar flight with a payload of five billion tons, using FF&S.
>(A *huge* payload. Some of the CT referees out there who liked FASA may
>know where my number is coming from.) So I checked out drive systems.

Sorry, 'fraid I missed that one.  Explanation, please? <sound of PCs
quaking in boots>

>STL travel stinks. And it revealed a *major* bug in the FF&S rules. At
>[...]
>higher." (p. 74)

>#$**$%^@! <This is a family mailing-list.> :)

>Per cubic meter of maneuver drive: (in metric tons)

>                 THRUST       FUEL USE  ...fuel per ton of thrust
>Daedalus drive: 1.5 ton   0.00050 ton/hr.     0.000334 ton/hr
>Fusion rocket   9.0 ton   0.00035 ton/hr.     0.000039 ton/hr
>HEPlaR drive:  33.4 ton   0.02917 ton/hr.     0.000873 ton/hr

>[...]

>The Daedalus drive is an order of magnitude *worse* in fuel efficiency
>than the conventional fusion rocket!!! Combined with its' worse
>thrust-to-mass ratio, the engine is fairly worthless.

<bing!> Wrong, but thanks for playing. See FF&S page 70, column 2, para
3, "FC"; "Fuel consumption, in tonnes, per hour per tonne of thrust."
                                                ^^^^^^^^^^^^^^^^^^^
So the Fusion Rocket line should actually be:

Fusion rocket   9.0 ton   0.00035 ton/hr.     0.000350 ton/hr

This makes the Daedalus slightly better, but still nothing like an order
of magnitude.

What REALLY worries me, though, is the fuel efficiency of AZHRAE
engines.  Has anyone actually tried to design a tech 8 surface-to-orbit
vehicle (NASP or similar)?  As far as I can see, it's not actually
possible to carry enough fuel to make orbit from an Earth-sized world.
(I'll go into details of the calculation only if necessary.)  Does
anybody have a fully-worked design for something of this sort?

>Any comments? Am I reading this wrong?

Only that table heading - and there are still big problems.

Roger ("I only wanted some NASP stats for Dark Conspiracy")

- - --
Roger Burton-West <> Reality hacker <> Economics student <> The Last Romantic
GEcon/CS d? p--- c++++ l u+(-) e+ m++@ s++/+ !n h+ f+ g+(-) w+ t- r+ y?
Mail me at [email removed] (or @uk.ac.ucl) or [email removed]
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Harrisberger's Fourth Law of the Lab:
Experience is directly proportional to the amount of equipment ruined.

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