Re: FW: starship-design: Pellet track

[kuo@bit.csc.lsu.edu (Isaac Kuo)]

L. Parker wrote:

>ISP and thrust are both important, and unless you are using voodoo, I don't
>see how you can say the rocket equation doesn't apply. A ramjet is still a
>rocket, not a warp drive. It still ingests mass and exhausts mass.

The rocket equation only applies to rockets--and even then only rockets
which do not refuel.  A rocket that does not ingest mass.

The rocket equation does not apply to any other form of propulsion,
including solar sails and ramjets.

>An ISP of 10,000 sec would require an enormous mass of pellets,

With a ramjet, an Isp of 10,000 requires a pellet track/payload
mass ratio of 1500 to reach .5c.  With a 10,000,000 kg ship,
that means 15,000,000,000 kg in pellets.  That's alot, but it's
about as reasonable as you're going to get for a manned interstellar
mission.
-- 
    _____     Isaac Kuo kuo@bit.csc.lsu.edu http://www.csc.lsu.edu/~kuo
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