clipka <ano### [at] anonymousorg> wrote:
> I think it all depends on whether you want hollywood-style space
> fighters -- that for some obscure reason are constantly firing their
> main engines anyway, and for much more obvious reasons may need to turn
> quickly -- or a real-world spaceship.
>
> A real-world spaceship will only occasionally fire /any/ engines of
> notable power at all, drifting unaccelerated most of the time, with
> plenty of time to change its attitude -- which is done mostly for
> thermal management (attitude towards the sun), scientific reasons
> (attitude towards a point of interest, though usually scientific
> instruments on a manned spacecraft will have their own degrees of
> freedom to track a POI), or to prepare for the occasional major course
> correction. To save weight there will only be a single set of engines
> for such corrections, mounted so that the array points away from the
> center of mass, usually at what is perceived as the rear end of the
> ship. Attitude changes will be done without haste, allowing for better
> fine-tuning as well as preventing any nausea-inducing effects (any that
> go significantly beyond the nausea-inducing effect of zero-g anyway).
> Actual course corrections /will/ involve notable g forces, but
> acceleration will be linear. No attitude changes will be made during
> such acceleration burns whatsoever, except possibly to actively
> stabilize the attitude(*). Any course correction procedure asking for a
> deliberate change in attitude during the acceleration burn would
> demonstrably be a waste of propellant.
>
> Docking is another matter; there, attitude is mostly kept unchanged and
> maneuvering thrusters are used for acceleration in arbitrary directions.
> But even then, such changes will be kept minute, to both keep relative
> speed low and -- again -- prevent additional nausea.
>
> For anyone interested in real-spaceflight mechanics, Kerbal Space
> Program is a highly recommended piece of software.
>
>
> (* Spacecraft with continuous-thrust engines like ion drives are an
> exception, but their thrust-to-weight ratio is extremely low anyway, so
> there's not much acceleration going on that could potentially induce
> nausea.)

I don't know that it's the acceleration that's causing the nausia in the MF
example above, as much as it's the dissonance between the physically percieved
motion of the ship and the motion as relayed to the brain by the eyes.

Like when you stand on a bridge, watching the water flow benieth you, and you
get the feeling that the bridge is moving the opposite direction, except in that
case, your standing still, while on the Falcon, you'd actually be in motion, but
not in the way your eyes tell you.

For the actual physics, I'll have to trust the experts.

Regards,
A.D.B.

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