Mark Simmons (
Sun, 29 Oct 2000 11:42:37 -0800

Lim Jyue writes,

>>Can those pea-shooter (beam spray gun) actually shoot through a MS like beam
>>rifles? Is their sniper rifle ammo-based or beam?
> The Sniper II's 90mm is definitely ammo-based, and there has not
>been any real information on what the Sniper II were supposed to carry, but
>an educated guess would be a beam rifle similar to those carried by the

  The Sniper II's rifle is supposed to be a beam weapon, but Izubuchi's
sketch of the rifle clearly shows it to be loaded with shells. I don't
think he really cared very much - note that the Alex's "beam rifle" also
has a magazine, which resembles a machine-gun clip rather than an E-pack
(which aren't supposed to have been invented for another three years anyway).

> Actually, we've never really had any good indication of how much
>fuel an MS could carry (though Mark implied otherwise) and the fuel
>consumption of the thrusters. While it might be more accurate to figure out
>all these to paint a picture of an MS's worth, the sad truth is that we
>don't really know these, and hence cannot calculate them.

  See my other message for precise figures as to propellant payloads. As
for the fuel consumption, this too can be derived from the specific
impulse - a measurement of rocket efficiency, expressed in seconds. We
can't say precisely what the specific impulse of the thermonuclear rocket
engines used in Gundam would be, but last time I was reading up on rocket
propulsion, I got the impression that the upper limit would be about 5000
seconds (ten times that of the space shuttle's main engines, which are
about as efficient as chemical rockets can get).

  In this case, the Rick Dias, with 16.5 tons of propellant, would be
able to generate 74.8 tons of thrust (actually 74,800 kg x 9.8 m/sec^2 =
733,000 newtons, in proper terminology) for 1,100 seconds - about 18
minutes. And that's assuming a pretty generous specific impulse figure.

  All told, the operating time for a mobile suit's thrusters will be
measured in minutes. That's why they use them only for short bursts of
acceleration, then cruise at this velocity the rest of the time.

> Since you can change facing in space by the application of a few
>apoogee motors, another good indicator would be the number of apoogee motors
>on an MS, but this information is often left out of most technique specs

  There are published 180-degree turn time specs - expressed in seconds -
for most mobile suits from classic Gundam, 0080, and 0083. It's possible
to guess at formulas for deriving these values, but Dafydd and I found
out that there's more than one formula that works for the available data,
so we don't know which one is correct. We do know it's based on thrust,
full weight, and number of apogee motors - plus the fact that adding
magnet coating effectively increases the number of apogee motors by 50%,
for purposes of computing turn time.

-- Mathematical Mark

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Mark Simmons / /
"If you can kill it, it's not a god, just a good old-fashioned monster."

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