In rec.arts.sf.science message <TbKdnffOHvUawQ3anZ2dnUVZ8tyqnZ2d@[EMAIL PROTECTED]
>
, Fri, 18 Jan 2008 08:00:05, Mike Dworetsky <platinum198@[EMAIL PROTECTED]
> posted:
>
>Assuming that as stipulated, using the least fuel is im****tant, i.e.,
>the rocket jockeys are not able to accelerate continuously but need to
>coast most of the time, and the orbits are circular (which they aren't,
>but it simplifies the thinking):
The answer depends largely on the potency of the drive.
With a low-impulse drive, whether high- or low-thrust, one merely moves
in or out by a small amount, and which it is will not much matter.
With a potent drive, one just blasts straight across in either case
(remembering turnover half-way) and both take the same time.
With a middling drive, your argument shows an effect of significant
magnitude : I'm not sure whether it encomp***** the Oberth effect or
that should be added.
ISTM that one *can* get from L4 to L5 by killing almost all of the
orbital speed. It takes 0.177 of a month to fall to Earth, and if
instead one goes just outside the atmosphere one will retrace, more or
less, one's path, taking 0.354 of a month to reach the original
distance. But it takes 0.333 of a month for L5 to travel to L4; and the
difference in timing=angle can probably be accommodated by using a
suitably-directed and comparatively modest amount of propulsion
more/less than that originally implied.
--
(c) John Stockton, Surrey, UK. ?@[EMAIL PROTECTED]
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