The Moon is a Harsh Mistress (33 page)

“Ninety-three
point one percent.”

“Yes,
sir. India is deeply interested in our grain so it seemed likely that she would
cooperate. She could grant us land, make labor and materials available, and so
forth. But I mentioned India because she holds a wide choice of possible sites,
very high mountains not too far from Terra’s equator. The latter is not
essential, just helpful. But the site must be a high mountain. It’s that
air pressure you spoke of, or air density. The catapult head should be at as
high altitude as feasible but the ejection end, where the load travels over
eleven kilometers per second, must be in air so thin that it approaches vacuum.
Which calls for a very high mountain. Take the peak Nanda Devi, around four
hundred kilometers from here. It has a railhead sixty kilometers from it and a
road almost to its base. It is eight thousand meters high. I don’t know
that Nanda Devi is ideal. It is simply a possible site with good logistics; the
ideal site would have to be selected by Terran engineers.”

“A
higher mountain would be better?”

“Oh,
yes, sir!” I assured him. “A higher mountain would be preferred
over one nearer the equator. The catapult can be designed to make up for loss
in free ride from Earth’s rotation. The difficult thing is to avoid so
far as possible this pesky thick atmosphere. Excuse me, Doctor; I did not mean
to criticize your planet.”

“There
are higher mountains. Colonel, tell me about this proposed catapult.”

I
started to. “The length of an escape-speed catapult is determined by the
acceleration. We think—or the computer calculates—that an
acceleration of twenty gravities is about optimum. For Earth’s escape
speed this requires a catapult three hundred twenty-three kilometers in length.
Therefore—”

“Stop,
please! Colonel, are you seriously proposing to bore a hole over three hundred
kilometers deep?”

“Oh,
no! Construction has to be above ground to permit shock waves to expand. The
stator would stretch nearly horizontally, rising perhaps four kilometers in
three hundred and in a straight line—almost straight, as Coriolis
acceleration and other minor variables make it a gentle curve. The Lunar
catapult is straight so far as the eye can see and so nearly horizontal that
the barges just miss some peaks beyond it.”

“Oh.
I thought that you were overestimating the capacity of present-day engineering.
We drill deeply today. Not that deeply. Go on.”

“Doctor,
it may be that common misconception which caused you to check me is why such a
catapult has not been constructed before this. I’ve seen those earlier
studies. Most assumed that a catapult would be vertical, or that it would have
to tilt up at the end to toss the spacecraft into the sky—and neither is
feasible nor necessary. I suppose the assumption arose from the fact that your
spaceships do boost straight up, or nearly.”

I
went on: “But they do that to get above atmosphere, not to get into
orbit. Escape speed is not a vector quantity; it is scalar. A load bursting
from a catapult at escape speed will not return to Earth no matter what its
direction. Uh … two corrections: it must not be headed toward the Earth
itself but at some part of the sky hemisphere, and it must have enough added
velocity to punch through whatever atmosphere it still traverses. If it is
headed in the right direction it will wind up at Luna.”

“Ah,
yes. Then this catapult could be used but once each lunar month?”

“No,
sir. On the basis on which you were thinking it would be once every day,
picking the time to fit where Luna will be in her orbit. But in fact—or
so the computer says; I’m not an astronautics expert—in fact this
catapult could be used almost any time, simply by varying ejection speed, and
the orbits could still wind up at Luna.”

“I
don’t visualize that.”

“Neither
do I, Doctor, but—Excuse me but isn’t there an exceptionally fine
computer at Peiping University?”

“And
if there is?” (Did I detect an increase in bland inscrutability? A
Cyborg-computer—Pickled brains? Or live ones, aware? Horrible, either
way.)

“Why
not ask a topnotch computer for all possible ejection times for such a catapult
as I have described? Some orbits go far outside Luna’s orbit before
returning to where they can be captured by Luna, taking a fantastically long
time. Others hook around Terra and then go quite directly. Some are as simple
as the ones we use from Luna. There are periods each day when short orbits may
be selected. But a load is in the catapult less than one minute; the limitation
is how fast the beds can be made ready. It is even possible to have more than
one load going up the catapult at a time if the power is sufficient and
computer control is versatile. The only thing that worries me is—These
high mountains they are covered with snow?”

“Usually,”
he answered. “Ice and snow and bare rock.”

“Well,
sir, being born in Luna I don t know anything about snow. The stator would not
only have to be rigid under the heavy gravity of this planet but would have to
withstand dynamic thrusts at twenty gravities. I don t suppose it could be
anchored to ice or snow. Or could it be?”

“I’m
not an engineer, Colonel, but it seems unlikely. Snow and ice would have to be
removed. And kept clear. Weather would be a problem, too.”

“Weather
I know nothing about, Doctor, and all I know about ice is that it has a heat of
crystallization of three hundred thirty-five million joules per tonne. I have
no idea how many tonnes would have to be melted to clear the site, or how much
energy would be required to keep it clear, but it seems to me that it might
take as large a reactor to keep it free of ice as to power the catapult.”

“We
can build reactors, we can melt ice. Or engineers can be sent north for
re-education until they do understand ice.” Dr. Chan smiled and I
shivered. “However, the engineering of ice and snow was solved in
Antarctica years ago; don’t worry about it. A clear, solid-rock site
about three hundred fifty kilometers long at a high altitude—Anything
else I should know?”

“Not
much, sir. Melted ice could be collected near the catapult head and thus be the
most massy part of what will be shipped to Luna—quite a saving. Also the
steel canisters would be re-used to ship grain to Earth, thus stopping another
drain that Luna can’t take. No reason why a canister should not make the
trip hundreds of times. At Luna it would be much the way barges are now landed
off Bombay, solid-charge retrorockets programmed by ground control—except
that it would be much cheaper, two and a half kilometer-seconds change of
motion versus eleven-plus, a squared factor of about twenty—but actually
even more favorable, as retros are parasitic weight and the payload improves
accordingly. There is even a way to improve that.”

“How?”

“Doctor,
this is outside my specialty. But everybody knows that your best ships use
hydrogen as reaction mass heated by a fusion reactor. But hydrogen is expensive
in Luna and any mass could be reaction mass; it just would not be as efficient.
Can you visualize an enormous, brute-force space tug designed to fit Lunar
conditions? It would use raw rock, vaporized, as reaction mass and would be
designed to go up into parking orbit, pick up those shipments from Terra, bring
them down to Luna’s surface. It would be ugly, all the fancies stripped
away—might not be manned even by a Cyborg. It can be piloted from the
ground, by computer.”

“Yes,
I suppose such a ship could be designed. But let’s not complicate things.
Have you covered the essentials about this catapult?”

“I
believe so, Doctor. The site is the crucial thing. Take that peak Nanda Devi.
By the maps I have seen it appears to have a long, very high ridge sloping to
the west for about the length of our catapult. If that is true, it would be ideal—less
to cut away, less to bridge. I don’t mean that it is the ideal site but
that is the sort to look for: a very high peak with a long, long ridge west of
it.”

“I
understand.” Dr. Chan left abruptly.

Next
few weeks I repeated that in a dozen countries, always in private and with
implication that it was secret. All that changed was name of mountain. In
Ecuador I pointed out that Chimborazo was almost on equator—ideal! But in
Argentina I emphasized that their Aconcagua was highest peak in Western Hemisphere.
In Bolivia I noted that Altoplano was as high as Tibetan Plateau (almost true),
much nearer equator, and offered a wide choice of sites for easy construction
leading up to peaks comparable to any on Terra.

I
talked to a North American who was a political opponent of that choom who had
called us “rabble.” I pointed out that, while Mount McKinley was
comparable to anything in Asia or South America, there was much to be said for
Mauna Loa—extreme ease of construction. Doubling gees to make it short
enough to fit, and Hawaii would be Spaceport of World … whole world, for
we talked about day when Mars would be exploited and freight for three
(possibly four) planets would channel through their “Big Island.”

Never
mentioned Mauna Loa’s volcanic nature; instead I noted that location
permitted an aborted load to splash harmlessly in Pacific Ocean.

In
Sovunion was only one peak discussed—Lenin, over thousand meters (and
rather too close to their big neighbor).

Kilimanjaro,
Popocatepetl, Logan, El Libertado—my favorite peak changed by country;
all that we required was that it be “highest mountain” in hearts of
locals. I found something to say about modest mountains of Chad when we were
entertained there and rationalized so well I almost believed it.

Other
times, with help of leading questions from Stu LaJoie’s stooges, I talked
about chemical engineering (of which I know nothing but had memorized facts) on
surface of Luna, where endless free vacuum and sunpower and limitless raw
materials and predictable conditions permitted ways of processing expensive or
impossible Earthside—when day arrived that cheap shipping both ways made
it profitable to exploit Luna’s virgin resources, Was always a suggestion
that entrenched bureaucracy of Lunar Authority had failed to see great
potential of Luna (true), plus answer to a question always asked, which answer
asserted that Luna could accept any number of colonists.

This
also was true, although never mentioned that Luna (yes, and sometimes
Luna’s Loonies) killed about half of new chums. But people we talked to
rarely thought of emigrating themselves; they thought of forcing or persuading
others to emigrate to relieve crowding—and to reduce their own taxes.
Kept mouth shut about fact that half-fed swarms we saw everywhere did breed
faster than even catapulting could offset.

We
could not house, feed, and train even a million new chums each year—and a
million wasn’t a drop on Terra; more babies than that were conceived
every night. We could accept far more than would emigrate voluntarily but if
they used forced emigration and flooded us … Luna has only one way to
deal with a new chum: Either he makes not one fatal mistake, in personal
behavior or in coping with environment that will bite without warning …
or he winds up as fertilizer in tunnel farm.

All
that immigration in huge numbers could mean would be that a larger percentage
of immigrants would die—too few of us to help them past natural hazards.

However,
Prof did most talking about “Luna’s great future.” I talked
about catapults.

During
weeks we waited for committee to recall us, we covered much ground. Stu’s
men had things set up and only question was how much we could take. Would guess
that every week on Terra chopped a year off our lives, maybe more for Prof. But
he never complained and was always ready to be charming at one more reception.

We
spent extra time in North America. Date of our Declaration of Independence,
exactly three hundred years after that of North American British colonies,
turned out to be wizard propaganda and Stu’s manipulators made most of
it. North Americans are sentimental about their “United States”
even though it ceased to mean anything once their continent had been
rationalized by F.N. They elect a president every eight years, why, could not
say—why do British still have Queen?—and boast of being
“sovereign.” “Sovereign,” like “love,”
means anything you want it to mean; it’s a word in dictionary between
“sober” and “sozzled.”

“Sovereignty”
meant much in North America and “Fourth of July” was a magic date;
Fourth-of-July League handled our appearances and Stu told us that it had not
cost much to get it moving and nothing to keep going; League even raised money
used elsewhere—North Americans enjoy giving no matter who gets it.

Farther
south Stu used another date; his people planted idea that
coup d’etat
had been 5 May instead of two weeks later. We were greeted with “
Cinco
de Mayo! Libertad! Cinco de Mayo
!” I thought they were saying,
“Thank you”—Prof did all talking.

But
in 4th-of-July country I did better. Stu had me quit wearing a left arm in
public, sleeves of my costumes were sewed up so that stump could not be missed,
and word was passed that I had lost it “fighting for freedom.”
Whenever I was asked about it, all I did was smile and say, “See what
comes of biting nails?”—then change subject.

I
never liked North America, even first trip. It is not most crowded part of
Terra, has a mere billion people. In Bombay they sprawl on pavements; in Great
New York they pack them vertically—not sure anyone sleeps. Was glad to be
in invalid’s chair.

Is
mixed-up place another way; they care about skin color—by making point of
how they don’t care. First trip I was always too light or too dark, and
somehow blamed either way, or was always being expected to take stand on things
I have no opinions on. Bog knows I don’t know what genes I have. One
grandmother came from a part of Asia where invaders passed as regularly as
locusts, raping as they went—why not ask her?