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And I had noticed that she had not answered my question.
(If ballistics bores you, here is another place to skip.)
A daisy-clipping orbit of Luna (assuming that Luna has daisies, which seems
unlikely) takes an hour and forty-eight minutes and some seconds. Golden Rule,
being three hundred kilometers higher than a tall daisy, has to go farther than
the circumference of Luna (10,919 kilometers), namely 12,805 kilometers. Almost
two thousand kilometers farther-so it has to go faster. Right?
Wrong. (I cheated.)
The most cock-eyed, contrary to all common sense, difficult aspect of
ballistics around a planet is this: To speed up, you slow down; to slow down,
you speed up.
I'm sorry. That's the way it is.
We were in the same orbit as Golden Rule, three hundred klicks above Luna,
and floating along with the habitat at one and a half kilometers per second
(1.5477 k/s is what I punched into the pilot computer... because that was what
it said on the crib sheet I got in Dockweiler's office). In order to get down to
the surface I had to get into a lower (and faster) orbit... and the way to do
that was to slow down.
But it was more complex than that. An airless landing requires that you get
down to the lowest (and fastest) orbit... but you have to kill that speed so
that you arrive at contact with the ground at zero relative speed-you must keep
bending it down so that contact is straight down and without a bump (or not
much) and without a skid (or not much)-what they call a "synergistic" orbit
(hard to spell and even harder to calculate)
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