The Man Who Sold Mars (6 page)

And from the lands of dreams an intense
searchlight shined from above, piercing the dark starlit sky to sparkle on the
hull of my dream made real – the Mars Transit Vessel, MTV, The Prometheus – the
ship that would carry me and my team through the stars.

Above her, the sound of our approaching helicopter
rotor blades rose as our helo maneuvered itself and its searchlight over the
glistening ruby colored form, in the evergreen woods just northeast of Moscow.

I smiled with pride at the fruits of this
special part of my quest incarnate.

# # #

So in love, I watched him, so pleased to
see Stephen so happy, as he watched a portion of a dream he’d had for over 30
years lying incarnate waiting for him.

# # #

Selena turned her attention to the ship,
studying it and unnoticed I watched her in awe, as if she were Venus rising
from the sea.  I wanted her so badly.  I just . . . I just couldn’t.

Still watching the ship, Selena said,
“She’s a beauty.”

Still watching her and very much in love
and meaning Selena I said, “Isn’t she?”

The helicopter continued on to a landing
at a heliport not far from Prometheus where Selena and I exited to enter an
awaiting van to be greeted by Tatyana, Gardner, Kevin, Hemmingson, and George.

Excited Tatyana greeted us, “Welcome to,
Zvezdny Gorodok,
Star City, birth place of humanities
first reach for the stars.  Here we have Prometheus, the pinnacle of a billion
years of human technology.”  Switching to her heavy Russian accent,
“Compliments of Russian ingenuity.”

Selena teased her, “World ingenuity,
built in Russia.”

Tatyana teased back, “Same thing.”

She laughed and we joined her, as our van
delivered us to the Prometheus.

Smiling, I walked along the length of the
massive ship, surveying it with the others.  “Amazing.”

Kevin was impressed by her size, “She’s
huge.”

Gardner too was awed, “She’s going to be
the home of 12 people for three years.  She has to be.”

George shook his head no.  “Not just
home—“

Hemmingson added another truth, “World.”

I couldn’t wait to go and added, “Gravity
and all.”

Gardner thought for a moment, “Gravity?”

Tatyana pointed.  “This section
containing the crew quarters and infirmary rotates, producing a gravity through
centrifugal force.  We’ve found that the average person loses about one inch
per month when in an exclusively weightless space environment.”

Hemmingson glanced at me, “Jesus, Stephen
you’ll come back short enough to recreate the roll of Tattoo in the remake of
the remake of the remake of the remake of the television show
Fantasy Island
.”

I pitched my voice up, “De plane, Boss. 
De plane.”

Gardner returned to his question, “So,
how exactly does centrifugal gravity work?”

Professor Tatyana answered him, “It’s
actually a combination of centripetal force and centrifugal force, which are an
action-reaction force pair associated with circular motion.  According to
Newton's first law of motion, a moving body travels along a straight path with
constant speed and constant velocity, unless it is acted on by an outside
force.

“For circular motion to occur there must
be a constant force acting on a body, pushing it toward the center of the
circular path.  This force is the centripetal, center-seeking force.  For a
planet orbiting the sun, the force is gravitational; for an object twirled on a
string, the force is mechanical; for an electron orbiting an atom, it’s
electrical.

“The centripetal force, the action, is
balanced by a reaction force, the centrifugal, center-fleeing force.  The two
forces are equal in magnitude and opposite in direction.  The centrifugal force
does not act on the body in motion; the only force acting on the body in motion
is the centripetal force.  The centrifugal force acts on the source of the
centripetal force to displace it radially from the center of the path.  Thus,
in twirling a mass on a string, the centripetal force transmitted by the string
pulls in on the mass to keep it in its circular path, while the centrifugal
force transmitted by the string pulls outward on its point of attachment at the
center of the path.

Tatyana looked at the group, some clearly
understood and some had no idea what she was saying.  But before she could say
another word, Hemmingson said, “
Sprechen sie English
?”

“OK.  At the carnivals sometimes there's
a circular ride that spins dizzyingly fast.  You stand inside it; your back
pressed against the wall.  It spins faster and faster until, suddenly, the
floor falls away.  But you don't fall with it.  You’re pinned to the wall by
forces that may be as great as 3g’s, three times the normal force of Earth’s
gravity.”

Hemmingson smiled, “Ooooooooh, I see.”

I chimed in, “For us, 1g is optimal.”

Tatyana continued, “When we were coming
up with designs for her the need for an artificial gravity was a paramount concern
to keep from returning a crew of Tattoos.”

George added, “One vision was of a huge,
rotating spacecraft like the one seen orbiting the Earth in the movie
2001 A
Space Odyssey
.

Tatyana continued, “But that large means
very, very, very expensive and many more things that can break.”

I supported her, “And a lot more
construction time and a much longer overall period from the start of the
project until the crew returns from Mars.

George added, “So, we went with a
smaller, internal, centrifugal, artificial gravity ring.

Tatyana continued, “A rotating spacecraft
produces the feeling of gravity on its inside hull.  The rotation drives any
object inside the spacecraft toward the hull, thereby giving the appearance of
a gravitational pull directed outward.  Often referred to as centrifugal force,
the "pull", is actually a manifestation of the objects inside the
spacecraft attempting to travel in a straight line due to inertia.

“In English, this happens to us all the
time.  You’re riding in a car going around a curve.  Sitting on your dashboard
is a CD case.  As you go around the curve, the case moves towards the outside
edge of the car.

“The car’s tires on the road have enough
static friction to act as centripetal force which forces the car to go around
the curve.  The CD on the slippery dashboard does not have enough friction to
act as a centripetal force, so in the absence of a centripetal force the case
follows a straight line motion.  The car literally turns out from underneath
the CD case, but from the passenger's point of view it looks as though
something, a phantom force, pushed the CD case across the dashboard.  If the
car you’re riding in has the windows rolled down, then the case may leave the
car or depending on your perspective, the car leave the case, as it follows its
straight line path.  If the windows are rolled up, then the window will deliver
a centripetal force to the case and keep it in a circular path.”

I added, “For us, the spacecraft's hull
provides the centripetal force required for the objects to travel in a circle,
if they continued in a straight line, they would leave the spacecraft.”

Hemmingson explored his rapidly growing
knowledge of artificial gravity, “So, the gravity felt by the objects is simply
the reaction force of the object on the hull reacting to the centripetal force
of the hull on the object, because in accordance with Newton, all forces occur
in pairs, and these two forces are equal in magnitude and opposite in
direction.  So artificial gravity is not an attraction between the object and
the hull.  It’s like butter versus margarine.  Woooo Hoooooo!  I’m learning
stuff.  I must be too sober.”

We laughed.

Hemmingson wanted to learn more, “
Algo
mas.
 
Algo mas. 
More.  More.”

And Tatyana obliged him, “From the point
of view of the people rotating with the habitat, artificial gravity by rotation
behaves in some ways similarly to normal gravity but has the following
important difference.

“With centrifugal force induced gravity,
unlike real gravity which pulls towards a center, this pseudo-force that
appears in rotating reference frames gives a rotational 'gravity' that pushes
away from the axis of rotation, the center.

“Centrifugal artificial gravity levels
vary proportionately with the distance from the centre of rotation.  With a small
radius of rotation, the amount of gravity felt at one's head will be
significantly different from the amount felt at one's feet.”

I added, “This can make movement and changing
body positions awkward.”

Tatyana continued, “Slower rotations of
larger rotational radii should not have this problem.”

Hemmingson was definitely catching on, “But
then there’s the size and expense problem.”

I agreed, “Exactly.  Also, the Coriolis Effect
gives an apparent force that acts on objects that move.  This force tends to curve
the motion in the opposite sense to the habitat's spin.  Effects produced by
the Coriolis Effect act on the inner ear and can cause dizziness, nausea, and
disorientation.  Experiments have shown that slower rates of rotation reduce
the Coriolis forces and its effects.  It’s generally believed that at 2 rpm,
revolutions per minute, or less no adverse effects from the Coriolis forces
will occur.  But as the radius decreases, RPM’s must increase to produce the
same gravity.  At theses higher rates, the Coriolis forces and effects increase
dramatically.  Some people can become accustomed to it and some do not, but at
rates above 7 rpm few if any have been known to become accustomed.  It is not
yet known if very long exposures to high levels of Coriolis forces can increase
the likelihood of becoming accustomed.  So, to reduce Coriolis forces to
livable levels, a rate of spin of 2 rpm or less is needed to produce 1g and the
radius of rotation would have to be 224 meters, approximately 735 ft or
greater.  The diameter would be about the equivalent of five football fields
end to end.

Fay realized the implications, “That’s a
HUGE ship.”

George added, “Instead, we thought we
might be able to make the ship’s diameter smaller and use a short radius
centrifuge within it.”

Tatyana resumed, “And, based on the
diameter of the Prometheus we can give the crew quarters and infirmary a
livable and workable gravity at about 6 rpm.  However, the crew has the ability
to increase it as much as 15 rpm and reduce the rate to as low as 1 rpm or even
zero if need be.

Fay was surprised, “Fifteen?”

I answered him, “If the body can become
accustomed to higher RPM's at long exposure we want to see how far we can push
it for future designs.

Tatyana gave a more practical answer, “Or
sustained periods at 8, 9 10 RPM may make 7 rpm feel like paradise and train
the body to accept 7 RPM as a norm.”

George very proud directed our attention
to the entire ship, “She’s a marvel of engineering.”

I agreed, “She’s far from perfect, but
that she is.”

Selena voiced her thought, which we
shared, “Beautiful.” And then she made the request we all would have made had
she not done it first.  “Let’s see the inside.”

We moved towards a walkway to enter an
airlock.  For a moment, I remained behind admiring the ship.

# # #

And proud of my Stephen, I stayed behind again
to admire my love, at this, his special moment.  Then I asked him a question
burning in my mind.  “Tell me.  For someone going to the stars, you never look
at them.”

# # #

I hesitated answering Selena, remaining
in silence, reflecting on the truth this other sister had hit upon.  “Do you
know how hard it is to be so close to something you love so much, but can’t
touch?”  I started to look up at the stars, decided not to and walked off to
rejoin the group entering the Mars Transit Vehicle.

# # #

Sad I watched Stephen walk towards the
ship, while I brushed away a tear, and soft to myself, said, “Yes, Stephen. . .
. I do.”

# # #

I sensed Selena was just standing there
and I returned to her, smiled and offered her my hand.  She smiled took it and
we crossed through an entry bay of the transit vehicle to rejoin the group. 
Tatyana tapped an entry pad and the door sealed behind us.  Machinery whirred,
air currents fluxed and after a brief moment the light on an internal door we
were facing changed from red to green.  Tatyana, keyed another entry pad, the
door opened and she walked forward, leading our tour as she talked.  “The
Prometheus is powered by Helium 3—“

Hemmingson joked, “What?  Like a
balloon?”

We all laughed except Selena who had a
burning question.  “I thought we were using deuterium.”

I answered her.  “We tried, but the
radioactive shielding requirements were a nightmare.”

And so did Tatyana.  “Helium 3 needs less
radioactive shielding, yields more useable energy and is not as destructive on
the shielding.  So, the weight requirement of the propulsion system is lessened
along with the internal radiation hazard to the crew.”