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9.0 The design of the spaceship



       The spaceship will consist of three major components: (1) the
   nuclear power facility, (2) the electromagnetic launcher/catcher
   and (3), the crew's quarters.  The momentum transfer propulsion
   system requires a very stable spaceship so as to avoid being
   hit by any of the high speed projectiles.  The best way to do
   this is to use spin stablization or what is known as the
   gyroscopic effect.  The entire spaceship will be spun axially
   about the length of the EMPL.   An incidental benefit of this
   action will be the creation of artificial gravity for the crew.
   This is extremely important for the health of the crew.  First,
   it will allow the crew to function fairly normally.  This means
   that walking, eating, working, etc. will all be pretty normal.
   But the hidden benefits will be that the crew will not suffer
   from a debilitating loss of strength and muscle mass (including
   the heart), and neither will it be necessary to have long
   daily exercise programs.  Presumably under artificial gravity
   the blood will not deteriorate either.  And finally, the crew
   won't suffer any bone calcium loss.
       The crew's quarters will be built in the shape of a ring
   surrounding a small part of the length of the EMPL.  The rate
   of rotation of this ring is of concern because spinning makes
   people dizzy.  Spin rates of 3 rpm or less do not cause
   dizziness [101, p.236].  The magnitude of the artificial gravity
   is given by the equation:
*      g = v * v / r;           9.0-1
       where "v" is the velocity and "r" is the radius of the ring.
       A simple program was written which produced the following
   sample table for a ring rotating at 2 rpm.
*  Table 9.0-1
       Radius       Circumference    Artificial Gravity
        (m)          (m)      (mi)      (in gees)
        216         1357.17   0.843      0.967
        219         1376.02   0.855      0.980
        222         1394.87   0.867      0.994
        225         1413.72   0.879      1.007
        228         1432.57   0.890      1.021
        231         1451.42   0.902      1.034
        The following was the result at 3 rpm.
   Table 9.0-2
       Radius       Circumference    Artificial Gravity
        (m)          (m)      (mi)      (in gees)
         90          565.49   0.351      0.906
         93          584.34   0.363      0.937
         96          603.19   0.375      0.967
         99          622.04   0.387      0.997
        102          640.88   0.398      1.027
        105          659.73   0.410      1.057
       It seems prudent to build a multi-layered structure for
   three reasons: (1) in case of a solar flare (see below) the
   crew can retire to the deepest interior for maximum protection,
   (2) in case of an exterior skin rupture and the associated
   sealing-off of some portion of the ship, it would still be
   possible to detour around the effected area, and (3) the more
   floors which are also ceilings or vice versa the more efficient
   our structure is.
       Our major concern is to protect the crew from radiation. Each
   year the average person on earth receives a total radiation dose
   of about 200 millirads.  It is broken down as follows:
*  Table 9.0-3
   Radiation source                         Dosage
   Natural sources in the body              34 mr/yr
   Cosmic rays (on earth)                   30 mr/yr
   Natural sources in surroundings          48 mr/yr
   Medical X-rays                           75 mr/yr
   Radioactivity from man-made sources      12 mr/yr
       Source:  [101, p.126]
       The primary danger in space comes from solar flares. (Galactic
   cosmic rays are discussed below.)  The sun has an 11-year cycle of
   activity and during peak activity (1991 was a peak year) huge solar
   flares can erupt at any time.  They spew lethal radiation into space
   which could kill an unprotected crew. (The Apollo
   crews were just lucky that no big flares erupted while they
   were in space.)  A radiation dose of 450 rads will be fatal
   to 50% of the population (LD50 = 450 rads) [101, p.124].  Lethality
   increases to 100% at about 650 rads [101, p.124].
   The following is typical of solar activity:
*  Tabel 9.0-4
   Frequency per solar cycle       Dosage
   1 or 2                         5000 rads(fatal)
   2 to 5                         500-1000 rads(fatal)
   20 to 30                       50-100 rads
      Source:  [17, p.479]
       A secondary worry is the limited danger from galactic cosmic
   rays.  According to A.E. Nicogossian, the interplanetary radiation
   level is 25-36 millirads per day [17, p.479] and the Martian suface
   dose is 12.5-18 millirads per day.  (The earth's magnetic field
   prevents most of the cosmic rays from reaching the surface.)  Imagine
   taking a trip to Mars which took two months each way and spent a
   year on Mars.  The radiation dose from cosmic rays would be roughly:
*  Radiation dose for 1 year on Mars (+4 months travel time)
   0.75 - 1.0 rads per month in space  <=  4  rads
   4.5  - 5.5 rads for 1 year on Mars  <=  5.5 rads
       The total galactic cosmic ray dose for the Mars trip would be
   less than 10 rads - a safe level.  However, one can see that a small
   solar flare could hit you with 10 times that - in a couple of days.
       Plants are less vulnerable to radiation than people are
   so the crew will be located in the middle of a multi-level
   design. Imagine a four floor design in which the top and
   bottom floors grow plants and the middle two floors house the
   9.1  Apartment size and weight estimates
       The size of the apartments will be standardized because
   everyone will be paying the same price for their billet.  There
   will be no human staff, i.e. all manual labor will be done by a
   few andriods.  Clearly the apartment size is limited only by its
   mass (weight).  We want to have apartments which are as large as
   practical without making the voyage substantially longer.
       Cabin volume on the Apollo flights was 3.03 cubic meters
   per person [112].  "Living Aloft" suggests that 600 cubic feet
   or 17 cubic meters are needed per person for voyages lasting
   more than 2 months [22, p.61].  This is 10 ft x 10 ft x 6 ft.
   We feel this is unacceptable.  Our recommendation is a central
   hallway with two-person apartments on both sides.  Each apartment
   would be 9 meters by 5 meters (less wall thickness).  The hallway
   would be 2 meters wide giving an overall width of 20 meters and
   length of 5 meters for 4 people.  The height would be 3 meters
   less floor thickness and space for lighting fixtures etc.  Thus
   the overall living volume would be 75 cubic meters (20*5*3/4)
   per person.
       All floors, doors, and walls will have to be strong enough to
   serve as exterior walls (or pressure hulls or bulkheads) because
   of the real possibility of a puncture or rupture somewhere.  This
   means a weight penalty, but we cannot permit a design which could
   cause the loss of the entire crew.  Clearly all junctions must be
   airtight.  This includes doors in walls.  There will be doors in
   hallways between apartments, but since they will be intended for
   emergency purposes only, their normal state will be open.
       The tentative design calls for four levels, the top and bottom
   of which would be used for crops and the middle two would house
   the crew.  The following analysis will be based on one segment of
   the ring which will be four levels (12 meters) high, 20 meters
   wide (two apartments), and 5 meters long.  The number of occupants
   will be 8 ( 4 apartments total, on two floors).  In the following
   the weight of floor and wall materials is estimated to be 1.0
   kilograms per square meter yet it must be able to withstand 0.333
   bars of interior atmospheric pressure.
*  Table 9.1-1    Weight estimate of apartments
       Component                Area          Weight   Per person
                               (sq m)          (kg)    (kg/person)
       Floor-ceiling       3 * 5 * 20 = 300    300       37.5
       Hall wall           4 * 5 * 3  =  60     60        7.5
       Exterior wall       4 * 5 * 3  =  60     60        7.5
       Apartment wall      2 * 3 * 20 = 120    120       15.0
       lighting                                  8        1
       air conditioning                         24        3
       electronics                              80       10
       air  ( volume )    100 * 2 * 3 = 600    269.2     33.65
                                               ---       ----
                                      totals   921.2    115.15

       Toilets, showers, and basins will have to be shared because
   we cannot afford the extra weight it would require to provide
   private facilities.  If you assume that each person spends an
   hour per day using those facilities, you can see that we would
   only need about 1/24 of the number of facilities.  We suggest
   that there be enough facilities that about 8 people share each
   one.  Androids will maintain the facilities.
   9.2  Hydroponic food production
       Many different crops will be grown on board the spaceship both
   to save weight and to provide fresh food for the crew.  Fresh food
   will make the long trip much more bearable.  Briggs and Sacco give
   the following table of human needs and waste production.
*  Table 9.2-1  Human needs and waste production
       Requirement         Per man, daily      Crew, daily
                               (kg)               (MT)
       Metabolic oxygen        0.9                0.9
       Drinking water          3.6                3.6
       Hygiene water           5.4                5.4
       Food                    0.6                0.6
       Waste production
       Carbon dioxide          1.0                1.0
       Water vapor             2.5                2.5
       Urine                   1.5                1.5
       Feces                   0.16               0.16
       Metabolic heat         12,660kj           12,660Mj
       Source: M.R. Sharpe, "Living in Space", Doubleday, 1969,
               p.107 as cited in [LB1, p.425].
       From experience one would think that the above food
   requirement is too low.  Perhaps it is dry weight only.  We
   shall assume 2 kilograms of fresh food per person per day.
   This is about 1.5 pounds per person per meal.
       In order to estimate the weight of the hydroponic food
   production facilities it is necessary to estimate both the average
   growing period of the crops and the average harvest index.  The
   harvest index is the fraction of the crop which is edible. Corn
   for example has a very low harvest index - about 5%, whereas
   turnips have a harvest index of 100% because people do eat
   turnip greens.  We shall estimate 50 days for the average growing
   period and 33% for the average harvest index.  Thus in order to
   harvest 2 kilograms per day per person, we must have a crop
   which has an average weight of 1 kilogram for 50 days or a total
   weight of 50 kilograms per person.  Since only one third is
   edible we must grow three times as much or 150 kilograms per
   person.  Now we can estimate the weight of the hydroponic food
   production facilities.
       This estimate is based on two levels of the same size (20x5x3)
   as used in the previous section for estimating the weights of
   personal quarters.  Only one floor and ceiling are required because
   the others were accounted for in the crew apartment estimate.
*  Table 9.2-2    Weight estimate of hydroponic facility
       Component                Area          Weight   Per person
                               (sq m)          (kg)    (kg/person)
       Ceiling (top floor)     5 * 20 = 100    100       12.5
       Floor (bottom floor)    5 * 20 = 100    100       12.5
       Hall wall           4 * 5 * 3  =  60     60        7.5
       Exterior wall       4 * 5 * 3  =  60     60        7.5
       Partition               3 * 20 =  60     60        7.5
       lighting                                 24        3
       air conditioning                         24        3
       air  ( volume )    100 * 2 * 3 = 600    269.2     33.65
       crops               2 * 5 * 18 = 180   1200      150
       water                                  1120      140
       soil ( volume )   80 * 2 * .25 =  40   1600      200
       equipment                               150       18.75
                                               ---       ----
                                      totals  4767.2    595.9
       There will be no meat on board with the possible exception
   of small amounts that passengers may choose to bring aboard as
   part of their personal weight allocation.  There are two very
   good reasons for this.  First, raising animals to be used as food
   is a very inefficient way to get nurishment.  And second, we
   can't afford their weight.  It is clear that animals must be fed
   and that implies growing food for the animals.  Of course in our
   situation, the animals could eat the two thirds of the crops
   which we would not eat and which represent waste for us.  However,
   discounting the food the animals need, there still remain two
   major problems with animals.  First, they must have space to
   live in which implies a structure to house them.  Second, they
   produce waste just like people which implies a significant
   additional volume of waste to be handled by our waste recycling
   system.  This in turn implies more mass.
       In summary, the mass penalty of animals is the sum of their
   weight plus the weight of their housing (including air) plus
   the weight of their waste disposal equipment.  Another way of
   looking at the situation is that those animals would be displacing
   people who could be carried instead.  So who would want to buy
   million dollar tickets for chickens, rabbits, or goats to fly to
   9.3  Comparison of grown vs carried food supplies
       There is a point in terms of crew size and trip duration
   where it becomes more economical to grow food for the crew
   than to carry it.  We saw in the previous section that the
   estimated mass of the hydroponic facility was 595.9 kilograms
   per person.  In addition we must add roughly 20 kilograms per
   person of waste processing equipment to recycle the inedible parts
   of the plants we grow. That makes the total roughly 620 kg per
   person for a trip of unlimited duration.
       NASA plans to resupply food to space station Freedom rather
   than to grow it on board.  The following data comes from Charles
   Bourland, Space Station Food Subsystems manager, JSC:
*  Table 9.3-1  90-day food supply for a crew of 8
       Food type              Volume        Weight
                        %     (cu m)         (kg)
       Frozen          56      2.947         985.0
       Refrigerated    20      0.992         351.8
       Ambient         24      1.247         421.8
          total       100      5.186        1758.6
       Source: NASA as cited in Ad Astra, Jly '90, p.26.
       At three meals per day per person this amounts to 0.814 kg
   per person per meal or 2.44 kg per person per day.  Thus at 254
   days the resupply weight will be 620 kg per person.  Or in other
   words, for any trip longer than about 254 days, it is cheaper to
   grow your food than to carry it.
       In fact the real breakeven point would be less than 254 days
   because we haven't included any weight penalty for storage space to
   carry the food or containers to hold it in.
   9.4  The spaceship environment
       The comfort of the crew will be the primary concern of
   the design but strong emphasis will be placed on reducing
   weight wherever possible.   The idea of the crew wearing no
   clothing probably would not be acceptable but we can keep
   the temperature quite high (say 85F) to encourage people to
   wear shorts or other lightweight garments.  This will have
   several helpful consequences: (1) personal luggage can be
   reduced, (2) the mass of clothing washed on a daily basis
   will be reduced, (3) water, electricity, and handling needed for
   the cleaning of garments will be reduced, and (4) the time spent
   by people in dressing and undressing will be reduced.
       The individual apartments will be occupied by two crew
   members or possibly by a couple and a child.  This will permit
   privacy and intimacy.  Of course intimacy between two crew
   members of the same sex will be entirely their own business;
   however, AIDS infected people will not be permitted on board.
       During the building of the spaceship, couples or pairs of
   crew members who will be sharing an apartment will be asked to
   either choose an apartment floorplan from a variety supplied
   by professional designers or to design their own.  This should
   quarantee maximum satisfaction with personal quarters.  A family
   of four would be allocated twice the space and could design
   whatever floorplan they wished.  Similarly a group of four males
   might wish to design a small bunkroom and have the remainder
   of their space as a game and TV lounge - maybe they are avid
   bridge players.  Perhaps a news agency such as CNN would buy
   four seats and configure their space as a broadcast station.
       The air, at one third of normal air pressure, will be
   a mixture of 29.5% nitrogen, 70% oxygen, and 0.5% carbon
   dioxide.  Normal air would weigh three times as much.  Even
   so we will be carrying 67.3 MT of "air".  Smoking will be
       Each person will have a weight allocation of one metric
   ton which is 2200 pounds.  This allocation will include the
*  Table 9.4-1  Overall crew weight estimate
       Item                          Weight(kg/person)
       Food production                595.9
       Water                           10
       Food preparation                20**
       Waste/wash facilities           50**
       Apartment                      115.1
                           subtotal   791.
       Body                            80 (male; 50 female)
       Furniture                       50
       Personal articles               50 (male; 80 female)
       Space suit                      50
                              total  1021.
       ** - SWAG
       Although we have exhausted our weight allowance, this is
   not a problem because the momentum exchange propulsion system
   can handle significantly heavier loads.  We will not be at all
   surprised if some of the estimates are too low.  We expect that
   the mass of the structure may have to be adjusted upward.
   9.5  Crew size and composition
       Perhaps the single most important reason that this space
   project will be successful is that we plan to take a very large
   crew - namely 1000 people.  Now people can say to themselves,
   "Hey, I could go on that trip if I wanted to."  Past space
   flights have been limited to such small crews that selection
   was restricted to people with special qualifications.  Not only
   will that not be the case this time, but we will offer billets
   to nearly anyone who can afford the price of the tickets.  We
   say "nearly anyone" because there will always be some restrictions
   such as: no drug addicts, no felons, no people with fatal
   communicable diseases, no bedridden people, no insane people
   and so on.  There will be very limited medical facilities on
   board the spaceship so it will be strongly recommended that
   babies and other people who need special medical attention not
   go.  Tickets will be non-transferable to prevent scalping
   and there will be both national allocations and limits as to
   the number of seats that can be purchased by individuals and
   corporations.  Some seats may even be sold by lottery.
       By opening the doors to people of many different countries
   we believe that funds for the project will be much easier
   to raise.  Of course we expect that about half of the crew will
   be women.  It is anticipated that anyone who can afford to buy
   one such very expensive ticket can very likely afford two - so
   that they will also buy one for their spouse.  Thus we expect
   our apartments to be filled with many married couples of many
   different nationalities.
       There is no doubt that some women or couples may wish to
   have the distinction of producing the first baby in space or on
   the moon or Mars.  While there will be no prohibition of this,
   it will not be recommended for the following reasons: (1) medical
   facilities on board the spaceship will be limited thus increasing
   the danger to both the mother and baby, (2) the baby will be far
   too young to remember the experience when he(she) grows up, and
   (3) caring for the baby will greatly reduce the mother's
   enjoyment of the trip to Mars (or elsewhere).  And finally, (4)
   babies (and children) will be charged full fare, thus couples
   who have babies will owe additional fares when they return.
   9.6  The primary power source - nuclear energy
       Nuclear fission is the only source of power which is both
   powerful enough and light enough to do the job.  Some time
   in the distant future there may be other alternatives such
   as anti-matter or nuclear fusion.  As was briefly mentioned in
   section 6.4, the particle-bed nuclear reactor appears to be the
   best candidate at the present time.   Brookhaven
   National Laboratory has built a gas core particle-bed reactor
   that can produce 200Mw from a 300kg, 1.0 by 0.56 meter package
   [72, p.302].
       A particle-bed reactor differs from an ordinary nuclear
   fission reactor in that instead of fuel rods, the particle-bed
   reactor uses tiny fuel pellets.  The pellets have a larger
   surface area per unit volume than do the fuel rods and thus
   increase the rate of transfer of heat energy to the working
   fluid [AW 33, p.18-20].  This means a higher power output from
   a smaller (and hence lighter) volume.  Current experiments
   indicate that a power density of 40MW per liter is possible
   [AW 68, p.20-1].  This scales up to 40,000 MW per cubic meter.
   This much heat should be sufficient to turn the working fluid
   into an ionized plasma.  The plasma could be run through a
   magnetohydrodynamic (MHD) generator to convert it to electricity.
   MHD power conversion is about twice as efficient as conventional
   power generation equipment [115, p.224]. Greater efficiency usually
   but not always implies less weight is required to do the same job.
   Soviet researchers are believed to be significantly ahead of the
   rest of the world in this field. This is another area where US
   taxpayers could save big money if Soviet technology were utilized
   to convert the thermal power into electrical power.
       Any components of the nuclear reactor and the MHD power
   generation system which can be fabricated on the moon will be. The
   remainder, perhaps including the fuel pellets, will be "thrown" to
   the lunar slide lander, moved to the north pole by railroad and
   launched from there to the spaceship assembly site via the polar EMPL.
   Although this is a circuitous route, it will use very little
   propellant and therefore should be cheaper than other means.
   9.7  Spaceship assembly and checkout
       Perhaps the first decision that needs to be made is where to
   assemble the spaceship.  The Lagrangian points, L1, L2, L4, and L5
   are the only real contenders.  They were discovered by the French
   mathematician Lagrange in 1772.  Points L1 and L2 are unstable
   whereas points L4 and L5 are stable.  The stability of L4 and L5
   are the first reason we prefer them.
       The second reason we prefer L4 and L5 has to do with launching
   materials from the north pole of the moon to our chosen point of
   assembly.  Notice that we must launch downward, that is below the
   horizon, in order to reach any of these points from the north pole.
       We have calculated the launch angle for these points.  It is
   shown in the following table along with some other interesting data.
   The second column was obtained from [61, p.61]. The third column gives
   the launch angle from the "top" of the moon - i.e. without regard
   to the fact that the north pole is 1.5424 degrees away from the
   "top".  The fourth column gives the number of meters the projectile
   will drop per kilometer of flight as it leaves the EMPL for the
   target Lagrangian point.  The last two columns give the time in hours
   for the projectile to travel from the EMPL to the assembly point
   assuming an initial velocity of 5 km per second for column four and
   1 km per second for column five.
*  Table 9.7-1   Earth-Moon Langrangian Points
   Point    Distance     Launch  Drop (m    Travel time (in hours)
            from moon     angle   per km)   5 km/sec   1 km/sec
   L1         57731      -1.724    30.1        3.2         16
   L2         64166      -1.551    27.1        3.6         18
   L3        381327      -0.261     4.56      21.2        106
   L4,L5     384400      -0.259     4.52      21.4        107
       Choosing between L4 and L5 is a little more difficult and it
   may be possible to use either one.  When we leave HEO for Mars or
   Jupiter, we will want to point the spaceship such that we cancel
   some of the earth's orbital velocity because Mars and Jupiter have
   lower orbital velocities.  At the same time we want the projectiles
   to pick up orbital velocity as they head inside the earth's orbit
   so that they will assume a higher velocity orbit around the sun
   inside the earth's orbit. It would seem that L4 which is 60 degrees
   in advance of the moon, might have a slight advantage in this case.
       In any case it will require a very careful plan to determine
   the order in which the components of the spaceship should be
   launched in order to permit the orderly assembly of the spaceship.
   Nearly all material used in the spaceship will originate on the
   moon.  This will save a lot of money.  Assembly will be done
   remotely from earth using the androids to perform the work.
   9.8  Financing
       The primary financing for this voyage will come from five
   sources: (1) sale of tickets, (2) sale of television broadcast
   rights, (3) sale of Martian souvenirs, (4) profits from the android
   business, and (5) profits from the hydroponics business.  Let's
   guestimate how much money each of these sources might raise.
       The Soviet space agency, Glavkosmos, has been offering week
   long flights in the Mir space station for about $10 million
   [71, p.54].  The Tokyo Broadcasting System (TBS) paid upwards
   of $12 million to have Toyohiro Akiyama fly on Mir.  Liftoff
   was Dec. 2, 1990.  Two days were spent en route on Soyuz and then 6
   days on Mir [AA 5, p.7]. While on board Mir, Akiyama broadcast a
   daily commentary on his activities - especially on how sick the
   weightlessness made him. A short article in Aviation Week [AW 34,
   p.22] of 5/6/91 reported that Helen Sharman of the UK was scheduled
   to spend 6 days on Mir with liftoff on 5/18/91.  Germany paid Russia
   about $12 million for a trip to Mir.  Claus-Dietrich Flade, a German
   Cosmonaut, spent a week on Mir from March 17-25,1992 in the company
   of two Russian Cosmonauts.  Austrian and French cosmonauts are
   scheduled to fly on Mir too [71, p.56].
       The point is that there is a small market already for
   joy-rides on Mir for $10 - $12 million a shot.  How much would
   people pay to go to Mars?  Very likely there would be a lot of
   people who could and would pay $1 million a seat to go to Mars.
   Perhaps we could even sell 1000 seats at $2 million each.  There
   are more than 250,000 millionaires in the US alone.
*      Sales of tickets  -  $2 billion
       The first point to make about broadcast rights
   is that the market value can be increased significantly by
   selling the rights on a country by country basis. Television sports
   contracts give some idea of the value of broadcast rights.
*  Sport                  Network   Cost     Period    Source
   1988 Summer Olympics   NBC       $300 M   16 days   (1)
   1992 Winter Olympics   CBS       $243 M   16 days   (1)
   1992 Summer Olympics   NBC       $401 M   16 days   (1)
   1994 Winter Olympics   CBS       $300 M   16 days   (1)
   Baseball               ESPN      $400 M   4 years   USA Today
   NCAA Basketball        CBS       $1.0 B   7 years   USA Today
   World Series, etc.     CBS       $1.08 B  4 years   Star Ledger
   NFL                    several   $3.6 B   4 years   USA Today
     (1):[116] The 1992 Information Please Sports Almanac, p.430.
       The value of a live telecast from a spaceship on the
   way to Mars or from Mars itself is difficult to estimate. None of
   the three major US networks (ABC, CBS, NBC) responded to my
   written inquiry regarding their interest in such a venture. But it
   is clear that its value can be increased by an order of magnitude
   by timely preliminary "hype".
*      Broadcast rights (worldwide)  -  $1 billion
       Marketing of souvenirs from the Moon or Mars certainly offers
   the possibility of generating some significant revenues, but the
   value of such souvenirs is difficult to estimate.  The Apollo
   program cost the US taxpayers at least $120 billion in 1992 dollars
   and it returned 382 kilograms of lunar soil and rocks. Those rocks
   cost the US taxpayers about $314 million per kilogram.  On a little
   more down to earth scale, pieces of the Berlin wall were sold for
   $10 in the US.
       Perhaps we could get $1000 per pound for moon rocks and $5000
   per pound for Martian rocks.  If the price is too high, there will
   be people defrauding the public by selling rocks from their back
   yards.  The value per metric ton would be: $2.2 million for moon
   rocks and $11 million for Martian rocks.  Who knows how many tons
   we could sell before the price would drop?
*      Martian souvenirs - $11 million per metric ton
       Profits from the android and hydroponics businesses will depend
   on how rapidly they are ramped up to large scale.  We believe that
   both of these industries have the potential of the world automobile
   industry.  The hydroponics business could be ramped up faster because
   there is no need to wait for product development.  On the other
   hand, hydroponics will have a lower profit margin than the android