A Space Settlement Design Proposal by:

Azhar Syed Azmi

Vienna International School, Grade 10


2001 Grand Prize Winner of the NASA AmesSpace Settlement Design Contest


Advised by Levente Felvinczi of

Vienna International School, Austria




 With the conclusion of the 20th Century behind ourbacks, it can be clearly seen that the century had good times and bad times.Even if it had been the most controversial century ever in the history of mankind, thetechnological advancements achieved by humans significantly made our meredreams alter into challenging goals. Amongst the dreams man has pondered upon,creating a settlement outside the perimeters of earth has always been thoughtof as impossible. The physical barriers between earth and the stars seem soclose to breaking, yet so far. It was not until the invention of high altituderocketry by William H. Goddard that space exploration became plausible. As thescience of rocketry has been continuously advanced and modernized, humans wereable to send objects into space by the second half of the 20thCentury. Shortly afterwards, humans flew to space, walked on the moon, andbuilt a space station. It is clear the next step for mankind is to set up apermanent base somewhere in outer space. The creation of Centurion, aspace settlement orbiting around L5 for 8,000 people would become the greatestfeat produced by the hands of man – it would materialize the dream of countlessgenerations from all corners of the world. Centurion would in effect be thestar product of the 21st century by the world, and symbolize aunited effort to promote technological feats for the good of not only a fewselected countries, but of all mankind. The economical and technologicaladvantages of having a permanent human presence in space would entail and enhancea more prosperous era on earth – the era of space exploitation. The developmentof space can be seen as the next stage of human evolution, as for the firsttime in history people are able to develop, manufacture and maintain a confinedenvironment in an inhabitable area. Not only will Centurion be economicallyadvantageous; it will immortalize mankind’s dignified spirit in an endeavorthat will captivate the world scientifically and economically. The time hascome for mankind to break its natural barriers and confined limits - the timehas come for mankind to embark into the New Frontier– space. The time has come to embark the challenge of creating Centurion. 



 However much space seems a harsh and lifeless habitat, italso provides significantly valuable resources that can be used to facilitateearth’s needs. Space is seemingly featureless, but actually consists ofnumerous hills and valleys of gravitation. With the knowledge of space byextensive research, it was concluded that space is impossible to live inwithout development of settlements, due to an absence of gravity, food, water, air and an atmosphere.There are also the facts that the temperature of space is near 0 Kelvin, andthat there are dangerous levels of radiation from the sun and from othercelestial bodies. Space is generally an empty dangerous and lifeless place, andso in living in such a location, a confined self-sufficient settlement isnecessary. The environment of such a settlement has to also be confined tobefit humans, and in doing so the environment has to be as earth-like aspossible. Centurion provides all of these factors, but also takes advantage ofspace’s positive factors, such as the usage of micro-gravity in manufacturingand the conversion of valuable sunlight into cheap, clean and bountiful energyfor use. Centurion also provides the considerations of the psychological andphysiological standards that humans require in a creative, qualitative andconservative manner.



 Thelocation of Centurion is situated in Libration point 5, or L5 (figure 1). L5 is a shallow gravity valley that existsin between the earth-moon system. Libration points provide a stable equilibriumfor orbiting objects revolving around them. Just as the deep gravity well ofearth provides a stable equilibrium for the moon to orbit with, L5 wouldprovide a stable equilibrium for Centurion to revolve around. It isadvantageous to maintain Centurion in the stable equilibrium created by L5because it would entitle the fact that Centurion would not be able to ‘wanderoff’ into other parts of space. The position of Centurion within the gravitywell of L5 would hence maintain a fixed relation with the point. If it isdisplaced in any direction, Centurion will always return to its formerlocation. L5 is situated at equal distance from earth and the moon. Centurionwould orbit L5 while accompanying the moon and earth’s orbit around the sun. 

 Apartfrom the positive ideals that come with attaining a stable equilibrium aroundL5, the cost of maintaining Centurion is also considerably lowered due to it’sgeographic position near the moon and earth. L5 provides the most suitablepoint in which productivity and cost of imports and exports, both from the moonand earth, are crucially lower than for other libration points. Taking intoeffect the enormous gap of cost to transport materials from the moon and earth,it is clearly understood that the moon is an important center for valuableresources such as oxygen, silicon and titanium, which Centurion requires. Thecost of transporting materials and humans from earth exceeds that oftransporting things from the moon mainly because of the difference in gravity,and the lack of atmosphere on the moon. As earth is a more massive body thanthe moon, it also has a higher gravity – six times that of the moon. The energyneeded to escape such gravity is then also high in comparison to the moon (figure 2). To provide this massiveamount of energy, the money needed surmounts that of the moon’s costs totransport materials. It is for this reason that Centurion relies massively onthe moon for resources that cannot be found in space, even if such materialsare available on earth. There is also the fact that the moon is an untappedresource, while earth is a highly competitive place where resources are beingconsumed rapidly. The Mass Driver, which will be situated in mining areas onthe moon, has the unique ability to send materials into space without the useof chemical reactions. This further lowers the cost of transporting materialsto and from Centurion. No fuel propellant is needed, butthe Mass Driver instead uses electricity to create magnetic fields toaccelerate cargoes containing goods into space. This invention is only possibledue to the moon’s weak gravity.



 Centurion comprises of four main geodesic spheres, a zero gravity heavy manufacturingarea, and a spaceport directly south of the micro-gravity heavy manufacturingcenter. (figure 3). Tubular links,connect these structures to make Centurion a cohesive central structure. Inprotecting the inhabitants of Centurion from high levels of radiation emittedfrom the sun, three meters of regolith, or lunar soil, covers the four main‘blocks’ and the linkways that connect them. The regolith blocks radiation fromentering the settlement due to its tire-like shape, which covers most of thestructures of Centurion. Because of the heavy weight the lunar soil holds, itwill not revolve like Centurion does to create gravity. The regolith ‘tire’ isa stable non-rotating mass, which is located around the maximum width of thefour main rotating geodesic domes. In addition, the regolith ‘tire’ has solarpanels on the top of it to absorb sunlight and convert it into energy utilizedin Centurion. Heavy manufacturing takes place directly south of the centralnon-rotating dome, as the center of Centurion experiences zero gravity. Theabsence of gravity is used to the advantage of Centurion’s industry income, asmany expensive items can be made that cannot be manufactured on earth.

 Because the four sectors are separated, each of the domes isable to maintain a different atmosphere, therefore creating various climates.Atmosphere is created for each individual geodesic dome, and therefore theclimate and air mixture of each dome can be completely different. By creating avariety of climates, the people living in Centurion have a psychologicalatmosphere similar to earth. To provide a healthy environment, the temperatureof residential and commercial areas range from 20C to 24, and a relative humidity of about 40%. Thesevalues are similar to earth’s atmosphere. Although compartimentation let’sCenturion have the ability to have separate climates, the climates of the foursectors will stay about the same, to make humans as comfortable as possible.The main use of compartimentation is in case debris penetration or if animbalance is developed in the ecosystem. If any of these two factors occur inone dome settlement, the other three domes can be ‘shut’ so as not to spreadthe disorder. Each domed settlement is independent of the other domedsettlements, and therefore all four settlements are self sufficient, includingthe provisions of food and water supply. Another main use of compartimentationis with agricultural areas. Agricultural compartments have a very differentatmosphere than that of residential and commercial compartments, as 24-hourlight is provided and a higher concentration of carbon dioxide is given. Thisis used to maximize the growth of plants, thus increasing the efficiency of theagricultural output. The carbon dioxide levels and the amount of light suppliedvary according to different species of plants, although they all generally usea high amount of carbon dioxide and light.



Volume m

Gravity g

Air composition :Oxygen Nitrogen kt

Temperature K Humidity %



4.7 x 107


12 ; 17.5

295 K, 

40% Humidity

Residential/ Commercial Area


4.7 x 107


12 ; 17.5

296 K 
40% Humidity

Residential/ Commercial Area


4.7 x 107


12 ; 17.5

297 K

42% Humidity

Residential/ Commercial Area


4.7 x 107


12 ; 17.5

298 K

42% Humidity

Residential/ Commercial Area

Telstra HM Center

8 x 106


8; 11.7

295 K

41% Humidity

Heavy Manufacturing Center

Pegasus Space Port/ Centuplex

4.7 x 107


8 ; 11.7

294 K

41% Humidity

Space docking center, recreational/ tourism area, research center

C.S.S Linkway System

12 x 107


15 ; 22.0

297 K

41% Humidity

Transportation route, Tourism/Administration area, control center


 Gravity in Centurion is provided by the continuous rotationof the outer ring, which compromises the four geodesic-domed settlements andthe C.S.S Linkway System. The continuous rotation that affects this outer ringestablishes a centrifugal force that mimics earth’s gravity. This artificialgravity is crucial in creating an earth-like environment in which humans cansurvive and contend with. The rotation of Centurion is the most feasible andeconomical way to provide artificial gravity. As can be seen in the table,gravity on the four main structures is similar to earth. As the centrifugalforce only affects objects in the perimeters of the rotation generated, theCenturion Air Terminal and Centraplex experiences zero gravity. Zero gravity,or micro-gravity, creates a weightless affect that humans cannot experience onearth. Due to the constant presence of gravity amongst the natural world,humans have not evolved to cope with the absence of gravity in space. In teststhat have been conducted by NASA and other aerospace organizations, humans canexperience nausea, disillusions, abnormal blood distribution and weaker boneswhile in zero gravity. Without gravity, the human brain is not able to maintainfunctioning procedures, at least until the human adapts itself in theenvironment. With the impossibility to live in zero gravity, the factor ofproviding artificial gravity is essential and necessary in Centurion. Theperception of zero gravity in space is not always negative, as there are majoreconomical benefits that derive from the absence of gravity. Heavy objectsbecome weightless, and movement is only restricted by inertia. Therefore heavy,large masses do not require the expensive supports used on earth. Impossiblemanufacturing processes on earth will be an important revenue producer forCenturion, as its heavy industry sector is located in micro gravity.Transportation will also be of advantage to zero gravity because significantlyless energy is required to travel and transport things around space. It is alsounderstood that there is a possibility of humans being able to adapt to microgravity, as humans have always been able to readapt to new environments onearth. In conclusion, the docks and the heavy manufacturing area of Centurionare situated in the central sphere (where there is no gravity) because of theabove-mentioned advantages.

 Pseudo gravityis provided by the continuous rotation of Centurion. Centurion will rotate at arate of 1 rotation per minute. The speed of rotations is selected because ofthe effect of the Coriolis force. The Coriolis force depends upon both thespeed of motion and its direction relative to the axis of rotation, which arefactors pseudo gravity fail to correct. Only the sensation of weight is givenby a centrifugal force. The Coriolis force can disorient the perception andvision of a human’s eyesight. It can confuse the mind and cause mental damageunto it. Although the Coriolis force only creates mild symptoms, the limitationof one rotation per minute limits the force to acceptable levels in Centurion.

 Thevolumes of each major structure are as given in the table: a total of 1.9 x 108for the four major settlements (Fortunessa,Solera, Argento, and Kejora), and 12 x 107 for the C.S.S LinkwaySystem. The energy usage of Centurion is 13.1 kW per person a day, which bringstotal consumption of electricity to 104.8 MW, including for agricultural,sanitation and other processes. The air compositions of all structures aresimilar to the air composition of earth, with the mass of nitrogen at a ratioof 1.26 towards oxygen (there is one gram of oxygen for every 1.26 grams ofnitrogen). The main use of having earth-like atmospheric conditions is toprovide a safe psychological and physiological haven for humans. To providelight in all structures, mirrors surrounding the central sphere reflectsunlight onto the surface of the four geodesic domes and the C.S.S. LinkwaySystem (figure 4). The sunlightthat reaches the surface of the structures is passed through chevrons thatabsorb harmful gamma rays (figure 5).The light that finally goes through the structures after being filtered bychevrons shines from the ‘sky’ of the settlements. The ‘sky’ refers to theceilings of the settlement, which are conditioned to look similar to naturalskies. This process of providing sunlight to the four settlements is simple,economical, and harmless. To regulate a night and day cycle, the mirrorsreflecting light to the ceiling of the four settlements can be turned atangles, therefore providing a range of light shades that can mimic the amountof light shown at different times of the day on earth. For example, the amountof light entering the four settlements can be at a maximum at 12 o’clock in theday, and little light during the night cycle from 7PM to 5AM. A little lesslight than noon can be provided in the afternoon, perhaps at 5PM. Lighting willalso be provided with the use of fiber optics, which is mainly applied in theunderground facilities of the four settlements. Electricity is provided byexternal solar panel structures that are on the regolith shield. The abundantsupply of pure sunlight provides Centurion with cheap, bountiful andeco-friendly energy that will also prove to be a valuable export. 



 Inproviding a safe settlement for the citizens of Centurion, materials used inexternal and internal structures are strong and reliable. Aluminum, titanium,iron, silicon and aluminum alloy are the main materials used in Centurion, andall materials are abundant on the moon. All major external structures are madeof titanium and aluminum alloy, while internal structures are made of aluminumalloy, aluminum, titanium and iron. Solar cells, windows, and electroniccomponents are made of silicon. The regolith tire is a basic donut-shapedaluminum structure, and is covered with 3 meters of regolith. The 5 geodesicdomes are made of strong titanium, and aluminum alloy. Within the manytriangles that complement the whole geodesic dome, titanium is used as ‘bars’that connect the nods where analogous triangle points meet. Aluminum alloycomprises of the rest of the geodesic domes, hence is used in covering thetriangle areas regularly crossed by titanium bars (figure 6). To reduce stress for the shell of thegeodesic domes used in Centurion, there are three identical layers of thetriangularly patterned shells. These take into account that the shells becomesmaller as they approach the center of the domes (figure 7). The use of a triple shell is advantageousbecause it is not safe to have only one barrier separating a pressurized areaand an area not pressurized. If there were a breach in the sole barrier,draconian damages would be inflicted upon the structure due to the rapid changeof atmosphere. The geodesic domes used in Centurion have three protectivelayers, therefore limiting the chances of a breach or damage inflicted upon theshell. If damage is inflicted, repairs can be swiftly executed before furtherdamage endangers the habitat on the geodesic dome. 

 Inconclusion, materials used in Centurion have to withstand stress caused by thecentrifugal force, stress caused by atmospheric pressure, and thermal stress.The ring shape of the settlement, in addition to the 8 spokes that link thering to the center, will withstand the stress caused by the centrifugal forcedue to its sheer strength and careful design. Centrifugal forces are present inCenturion because of the rotating masses. The spokes interconnect Centurion toformulate it as a cohesive mass united within the perimeters it uses. Toconfront the stress caused by internal atmospheric pressure, the triple shellwall compartment gradually reduces pressure to reduce the stress created.Therefore, pressure levels do not have huge difference between a singlebarrier, which would create enormous atmospheric pressure. Instead, the threebarriers present in the shell of the geodesic domes will withstand atmosphericpressure stress in three steps. Thermal stress occurs when a heat gradientdevelops, causing the material to bend or expand. To mitigate this naturalreaction, the triangles that cover the geodesic domes have flexible joints ineach three points, causing the geodesic dome as a whole to be slightlyresilient and flexible. The numerous joints are flexible enough to be able tominimize the chances of cracks and bores within triple shells.

 Thesolar radiation in space is very harmful to humans, due to the absence of aprotective atmosphere to block dangerous rays. The intensity of solar radiationin space is 1390 Watts of sunlight, which is almost twice the maximum of 747Watts experienced on earth. There is 7.5 times more sunlight in space than onan average area on earth. Other than harmful rays, the sun also emits damagingsolar flares, in a way yet inexplicable. At times, areas of the sun store upvast amounts of energy, which it releases in a violent and almost explosivemanner. The energy is released through the chromosphere and into the corona,whence it escapes as a ripple in the solar wind. As electromagnetic waves areinvolved, electronic devices may be damaged if the energy ever reaches objects liableto be damaged. Objects that can be damaged include satellites, space shuttles,and solar panels. Due to the dangerously high radiation levels, Centurion isprotected with the use of mass shielding. The protection given by 3 meters ofregolith successfully absorbs enough radiation, so the radiation level isroughly similar to the amount received on earth. As the tire-shaped protectivebarrier is not connected to the rotating area of Centurion, the settlement usesa magnetic force to stay centered in the protection system. Centurion thus willnot collide with the regolith tire, and will be infinitely in a stable positionwith the protection system. With the use of the protective system, theradiation that passes through into the domes and tubes will have radiationlevels similar to the average amount that reaches the surface of earth. Toabsorb the high amount of rays, directly above the settlement of the domes andtubes chevrons are adopted. Although chevrons absorb sunrays, they also letlight pass through to the settlement in a specially designed manner (figure 5). After light passesthrough the chevrons, the radiation level of sunlight reaches 0.5 rem/yr (theaverage radiation level on earth), and the harmless sunlight transcends throughmulti-layer glass. The use of multi-layer glass is to protect the settlementfrom the many various dangers, as well as providing a precaution to possibledisasters. Each of the four-layered glasses contributes different propertieswith which to protect the inhabitants of Centurion. The first glass layerreduces thermal stress levels in the settlement, the second provides amechanical advantage in case of accidents, and the third layer forms a barrieragainst electromagnetic waves emitted from the sun (figure 10). 

 Energyin Centurion is, as mentioned, provided solely with the beneficial use of solarpanels. The total energy use includes the utilization of solar illumination forliving areas, the agricultural areas, and basic electricity for variousfacilities and areas. This amount of energy is feasibly generated predominantlybecause of the copious supply of pure sunlight and the large amount of space inwhich solar panels can be positioned. To generate this amount of energy, 804960m2 of solar panel area is used, in addition to producing a surplusamount of energy in case of emergencies and unnatural shortages.  

Solar EnergyValues


Energy use per Capita in Centurion

13.1 kW

Total Energy Use in Centurion

104.8 MW

Solar Panel Area

804,960 m2

Intensity of Solar Radiation per Sq. Meter in Space

1390 W

Intensity of Solar Radiation per Sq. Meter on Earth (maximum)

747 W


 Centurion is divided into two main divisions - the rotatingstructures and the non-rotating structures. The rotating structures consist ofthe four geodesic domes (Fortunessa,Solera, Argento and Kejora), the torus that connects the domes, and theeight tubes that connect the rotating division to the central sphere. Thenon-rotating division is composed of the central sphere (Centuplex), PegasusSpace Port, and the Telstra HM Center. If population growth or industrialexpansion occurs in the forthcoming years after Centurion is created, domes canbe built around the existing torus (figure11) to cater to increased needs. Slight growth can be conditioned withterrace ‘expansions’ within the four geodesic domes. The terraces would provideland for housing or other necessities that are in demand. 

 Robotsdue to many reasons do the construction of the major structures of Centurion,which include the triple shell of the domes, significant buildings andfacilities, and cables. Centurion introduces a way of automation forconstruction techniques with which robots have an overwhelmingly huge task. Forexample, large robot arms (figure 12)are used to transport and construct external and internal structures, crawlingrobots for mounting inner and outer shells, and fast robots are used totransport goods around Centurion. Automated robots are used for repetitive anddangerous tasks due to the expensive cost of human labor. As human workers willhave to be taken from distant earth, the cost is not justifiable for jobs thatcan be done by robots. The large amount physical dangers robots are prone to inwork proves to be a risk to humans, and so as human lives are more valuablethan robots, they are used in dangerous fields. Robots are also used inaccomplishing repetitive tasks, because humans feel less inclined to work inpsychologically boring conditions, which will affect the way they work.Efficiency is also a key that robots hold, due to their lack of emotions. Inshort, robots contribute a large percentage to the labor being done inCenturion due to their aspects as cheap, efficient, reliable, user-friendly andstrong. Not only are robots able to work in the most dangerous of environments,they also only need electrical energy to function properly. Humans, on theother hand, depend upon food, water, oxygen and comfort to work efficiently. Inconclusion, automated robots present a large portion of the workforce becauseof their many advantages, as well as because humans are in short supply. Humansare employed to carry specific tasks such as the control of robots, themanagement of facilities such as recycling and manufacturing, and in theobservation of any damages and dangers associated with Centurion. Humans arealso tasked to control communication systems, and to assists robots inemergency breaches or breakdowns.  



 Thespheres that make up a significant amount of Centurion’s habitable areaare FortunessaSoleraArgento, Kejoraand the smaller sphere Centuplex.Centuplex is the central area of Centurion, and is thus the center for innercommunication systems and the transport of goods and people. The surfaceconditions of each of the five domes vary slightly, but all have atmospheresthat make humans feel comfortable. Air compositions are healthy and comfortablein all spheres. All these aspects contribute into making Centurion a relaxed,comfortable and safe settlement both for permanent citizens and tourists. Apartfrom the spheres, all other areas of Centurion also have comfortable atmospherefor optimum ease.

 WithinCenturion, the location of volumes for residential areas is in the fourrotating geodesic domes (figure 13) (Fortunessa, Solera, Argento, and Kejorarespectively) because the domes possess the most suitable areas to housepeople. Advantages include the simple organization and maintenance for thesimilar domes, the abundant space, and the straightforward transportationroutes for each of the domes. These factors justify their location as the areain which people live in. Inside the four rotating geodesic domes, educational,commercial, manufacture and agricultural volumes are also situated. Bypositioning these volumes in the domes, the people of Centurion can reach needssuch as education, food and medical services with great ease, as the‘Centurians’ live in the same domes. Tourism areas include half the torus (figure 13) connecting the domes in a ring shape.The tourism areas will providethe influx of tourist with recreational and entertainment areas, while alsoproviding hotels for their stay. The citizens of Centurion are also able toenjoy the recreational and entertainment facilities. The other half of thetorus is used for administration volumes (figure 13).This includes organization headquarters, and community centers. Manufacturingwithout gravity is done in the Telstra HM Center, where the absence of gravitymakes heavy manufacturing easier. This non-rotating area is directly south ofCentuplex (figure 13). Further south of theTelstra HM Center is the Pegasus Space Port, a docking facility for spaceshuttles and ‘trains’ carrying goods (figure 13).The fact that Pegasus Space Port (PSP)is the farthest area from the main Centurion structure lessens the probabilityof hazardous crashes by space shuttles with Centurion. 

 Thevolumes for water systems, power systems, power grids, sewage systems,communication systems and computer network systems are all underground, toprovide safety and space for people on Centurion (shown on various cross-section maps). The transportationsystem of Centurion, as well as the numerous stations, are above ground torelieve the high density of buildings under the surface of Centurion. Althoughthe various systems interconnect Centurion (figure 13+14), the systems are also designed to be able tooperate independently in each dome. In effect, the transportation systemdesigned for use in Centurion is redundant, therefore providing higher levelsof safety. 



 As shown on the various mapsof the different geodesic domes (appendix), allvolumes for agricultural-related areas are underground. This includes areas forfarms, harvesting, drying and processing before foodstuffs can be sold atcommercial areas above ground. The area used for agriculture has a higher thanaverage temperature, as well as high levels of carbon dioxide. The amount oflight that illuminates the agricultural area is intense to accommodateexcellent levels of plant growth. As the atmosphere is completely pre-plannedand designed, Centurion’s agricultural area is significantly more efficientthan average farms on earth. The areas used for drying and processing are alsoin subterranean levels, located above the agricultural farmland. These twoareas have environments similar to the rest of Centurion, due to the fact thatplants are not grown in the areas. In addition, drying and processing areas areworking areas for humans, who need comfortable environments to live in. 

 Asstated previously, energy in Centurion comes in three forms: Electricity,thermal heat, and solar illumination. Electricity is generated with the use ofsolar cells on top of the regolith tire, thermal heat is produced by the solarfurnace, and solar illumination is provided with the use of mirrors to redirectsunlight (figures 3 and 13). Solar Illumination and thermal energy are notcreated with electricity, because a considerable amount of energy is wasted dueto the energy conversion. The use of mirrors and a solar furnace for these twoessential needs makes the energy system of Centurion more reliable andefficient. If electricity is converted for the various energy requirements,complex power grids and heaters will have to be implemented, thereforeaugmenting the complexity and cost. This is not the case for Centurion, due tothe high usage of mirrors and a solar furnace. Power plants are present in eachdome, albeit underground to provide safety to ‘Centurians’. Within Centurion,each dome with its neighboring tube is capable of providing energy for anotherpart of Centurion in case of emergency. 



 Internal communication inCenturion comes in many forms. Telephone cables, wireless equipment, and videoconnections are all used to help people communicate with each otherefficiently. A Centurion computer network is also implemented to helpinformation technology become connected throughout Centurion. All of thesedifferent kinds of services provide audio and visual communication withinCenturion for the general use of the people. In addition, a secure network isused by administration authorities in case information that is not meant forthe public is present. For emergencies, light and sound warning systems areintroduced throughout all parts of Centurion. The use of both light and soundhelps warn everyone, including blind and deaf people, of imminent danger towardstheir lives. 

 External communication helps Centurion trade information withEarth, bases on the Moon, mines on asteroids, and space ships that is incoming,outgoing, or just passing by. Electromagnetic and radio waves are used in theprocess. To collect and receive information from outside Centurion, satellitedishes are operated. The diversity of ways in which to communicate, bothinternally and externally, help reduce redundancy on a single form ofcommunication. This in turn helps Centurion communicate efficiently. 



 Theinternal transportation system operated within Centurion is simple andefficient. The major transportation route connecting the four geodesic domesaround the torus is a multi-lane conveyor belt that moves at various speeds (figure 15). Similar to conveyorbelts used in airports, the ones in Centurion will transport people at a speedthey wish to travel at. The four belts are adjacent to each other and run atdifferent speeds (The Conveyor Belt System – CBS, is shown onvarious maps). Underneath the conveyor belts, goods are transportedwith the use of ‘carriers’ connected to the underside of the conveyor belts (alsoshown in figure 15). The carriers use magneticpower to transport goods in steel packages. Due to the relatively small size ofCenturion, conveyor belts are a simple solution to make traveling aroundCenturion harmless and trouble-free. Inside the four rotating geodesic domes,the main use of transportation (aside from walking) is the use of four-wheeledvehicles (figure 16). Thevehicles use human force or electric motors. Either energy providers areoptional because the use of human pedaling promotes exercise, while in steepareas electric motors are a better option. Either way, these simple vehiclesare comfortable and safe. They also reduce the amount of energy usage,therefore scaling-down the cost of Centurion. The pedal-powered vehicles also reducethe dangers of vehicle crashes due to its relatively safe speed and absence ofharmful chemicals. Up to four people can be transported in the internalvehicles.

 Centurion’s imports are brought in to the Pegasus PortFacility, where all imports and exports go through (figure 14). From the port, distribution of goods for thepeople of Centurion follows various patterns, depending on the point of use.If, for example, goods are to be brought to a house in one of the rotating domes,the goods will have to be brought from the port to Centuplex. From Centuplex,the goods are transported via one of the spokes directly to the center of thedesignated dome. Sequentially, the goods are brought underground to the dome’srobot route system. The goods are then given to a robot, which transports themto the exact home through the numerous underground tunnels. Coincidentally, therobot route system is not only used to transport goods to houses, but also tocollect garbage. Robots are used at a major scale in Centurion because of thenumerous benefits they bring. For goods to that are transported from onerotating dome to another, the conveyor belt is introduced as agoods-transporter. The spokes are not part of the conveyor belt system becauseof their lack of stable gravity. Due to this, large square elevators are usedto transport both people and goods (see map of spoke elevatorin appendix). 

 Insummary, the internal transportation system does not use any complex structuresdue to the confusion they bring, and also because of the relatively small sizeof the settlement. Robots aid in transporting goods, because they are efficientand reliable, but also because humans are only liable to do extremely importanttasks. Eco-friendly vehicles used within domes also add to the simplicity ofthe transportation system, therefore reducing energy costs and production.  



 Thepeople of Centurion require a healthy and abundant supply of water. Due to thelack of liquid water in space, production of water is extremely vital andimperative. In addition, water is minimally wasted due to the completerecycling of gases, liquids and solids. Water is not only important for thebody; it is also essential for sanitation. Part of the water is obtained fromthe atmosphere by the process of condensation (figure 17). Before it is drinkable, ultra-violetequipment purifies the water of germs and viruses. Plants provide a generoussupply of air condensate, justifying the high amount of trees present inCenturion. Water is also provided with the recycling of liquid waste. Waterpurification facilities process liquid waste and produce the maximum amount ofclean, recycled water as possible. Recycled water is used for watering plants,sanitation purposes, and also for drinking. Each dome has its own watermanagement system, with individual recycling and waste treatment facilities. Incase of emergencies, each dome has the capacity of providing clean water foranother dome, therefore lessening the danger of water shortages. 

 Household and industrial waste is managed with the use ofsewage systems and efficient waste management facilities. Each dome has itsindividual waste treatment system, and therefore is independent of other areasof Centurion. In each dome, a sewage system covers every inhabited floor,including underground levels. Sewage pipes bring waste from structures towardsthe central waste treatment center. From the waste treatment center, purifiedwater is released into separate water pipes that are also connected into everyindividual structure in the domes. With the combination of recycled andcondensed water, each dome in Centurion is capable of providing water foritself as well as for another dome in case of an emergency. 



 The four rotating domes,along with the central dome, each have slightly different climates tofacilitate the growth of a diversity of plants and fruits. This effectivelypromotes variety to emulate the climatic conditions of different places onearth. As shown in the structure table, the temperature fluctuates within 10K,and the humidity varies by 10%. The air composition is similar in allstructures, but is still slightly different.

 Theatmosphere is provided and controlled by air pumps that regulate the aircomposition of Centurion. By regulating the air composition, the pressure ofeach structure can also be controlled. The control of both pressure and aircomposition creates a man-made atmosphere for each structure, according to it’satmospheric needs. Nitrogen and oxygen, including other gases, are supplied andmanaged by air pumps and computer systems. The computer systems analyze andmanage the supply and demand of air composition in each section of Centurion.

 Climatein Centurion accounts for the humidity and temperature of each section ofCenturion. Humidity is created by the managed provision of humidifiers and withthe amount of trees planted within each section. Although the humidity of eachstructure does not reach extreme levels, it varies diversely. Temperature iscontrolled with the use of heaters. The amount of heaters in each structurevaries to promote dissimilarity.

 Illumination in Centurion is basically controlled by mirrorsthat redirect sunlight to the inhabited areas of Centurion. As the mirror’sangle to the sunlight can be changed at any time, the light directed towardsthe rotating section of Centurion can also be altered. In this way, day andnight cycles can be regulated to mimic earth’s day and night cycle. Asexplained, at night the mirrors divert the sunlight away from the rotatingsection of Centurion, while in the day hours the mirrors direct sunlightstraight at the inhabited areas. In the morning and afternoon, only a portionof the light enters the rotating areas, due to the mirror’s exact angle withthe sunlight. The angle is half way between the night angle and the day angle. 

 Agricultural sites have a different atmosphere, climate andweather condition than the areas inhabited by people. Plant life requiresdifferent conditions to reach optimum growth, which is why Centurion providesagricultural areas with a different atmosphere. The amount of carbon dioxide inthe air is significantly higher, while humidity and temperature levels are alsogreatly enhanced. There is no day and night cycle in agricultural areas; theplants experience constant sunlight to intensify optimum growth. With all theseconditions, plants will experience continuous growth and health.  



 The partition of Centurioninto several distinct volumes promotes the diversity of environments that canthrive. In addition, Centurion embraces various cultural, architectural andecological habitats within the different environments (seeappendix). The cultural and architectural designs of different areas ofCenturion include Oriental, South-East Asian, European, Latin American andNorth American. The diverse environments in Centurion include tropical,temperate and warm climates. Due to the diverse environments, different plantspecies are able to be grown, adding to the colorful blend of biodiversitysimilar to Earth. This variety of living conditions alleviates stress andhomesickness, because Centurion is as earth-like as feasible. Centurians areable to move from one living environment to another, thus enhancing freedom andmitigating the feeling of ‘confinement’. Due to health and comfort risks, thetemperature and humidity of all areas of Centurion are not extreme, althoughare still diverse. In essence, the atmosphere, environment, and culturalbackground of the different areas of Centurion cater to the taste of people whochoose to live in Centurion. The vivid mixture of ethnic cultures increasesinterest and experience amongst Centurians, while also promoting cooperationand partnership among different cultures.

 Residential areas are positioned within the four rotatingdomes only. Although the amount of space provided by each dome varies slightly,all domes have space for 2000 people each. The residential areas are generallyorganized to boost efficiency, but are also somewhat unorganized to promotediversity. The density of residential areas is low, to provide comfort andspace for the growth of plants. These two factors help make Centurians feel asrelaxed as possible. The residential areas of Centurion can be viewed in manyways to the suburbs of successful metropolises such as Toronto and SanFrancisco, where prosperity and security have helped in creating excellentliving conditions.

 Withinthe inhabited domes, service industries provide people with necessities andoptional services. Barbershops, grocery shops, psychological relieving centers,massage parlors, restaurants and Internet cafes are all including, givingoptimum comfort for Centurians. Most service industries are located in theindividual domes, while a few are in the C.S.S Linkway System. The numerousdifferent services help alleviate boredom, which is important in a settlementfar from earth. The service industries present in Centurion also extenuatinglygratify the people of Centurion with helpful medical, social and entertainingbenefits. 

 Educational areas, including volumes for both adults andchildren, are located exclusively in the four rotating domes. Educationalfacilities include schools, kindergartens, a university, libraries and amuseum. All structures have communication cables, videophone capabilities and theessential needs such as water and electricity. In addition, robots and othermechanical machines are heavily used to provide education.

 Medicalassistance areas are also in the four rotating domes. Medical facilitiesinclude hospitals and emergency volumes. Advantages of having medicalfacilities within the four domes include the short distance needed to travel,and the abundant space that is provide for medical area volumes. The medicalfacilities in Centurion are high-tech, efficient, clean and sufficient forCenturians. Robots and other mechanical machines are used significantly toboost efficiency and safety. The emergency volumes are separate from thehospitals because it helps badly injured people receive supplementaryattention. 

 Parksand recreational sites are located in the four rotating domes as well as thelinkways connecting them. Both parks and recreational sites offer plentifulamounts of trees and other plants. These areas thus are able to produce fruitsand vegetables that are a part of a Centurian’s diet. The abundance of plantlife aids in keeping Centurians in touch with nature, which is especiallyimportant in a man-made habitat. The parks and recreational facilities alsoencourage exercise and leisure to be a part of Centurians. The two areas willhelp children as well as adults to embrace nature and preserve communityservices. Structures within parks and recreational sites include slides,swings, seesaws and other classic children structures. 

 Sportsfacilities are located within the four rotating domes as well as the linkwaysconnecting them. The sport facilities include excellent structures for use invarious sports- basketball, soccer, hockey, ice skating and hockey, badminton,bowling, tennis and are including, in addition to unique sports such as sepaktakraw (played in South-East Asia) and croquet. The wide range of sportsavailable helps increase amusement and foster culture understandings. The sportfacilities, similarly to the parks and recreational facilities, will also promoteexercise and social activities. Promoting social activities is exceptional andnecessary in Centurion, because it is a relatively small settlement far fromthe nearest human population (earth). Sporting events are also encouraged, andrange from tournaments to leagues. The Annual Centurian Marathon, for example, is a marathonaround the rotating section of Centurion (see appendix).The marathon encourages exercise while also ameliorating the social fabric ofpeople in Centurion. 

 The AdministrationSection of Centurion is situated in half of the torus that links the fourgeodesic domes. Administration structures include organization headquarters,community centers, communication centers, and computer network centers. Theadministration section is where most workers in the structure of Centurionwork, which is why the section is the main control center of the settlement.The administration section helps lead Centurion in an efficient and safemanner, and provides Centurians with a ‘government’ they can trust andidentify. The administration section is where all adjustments, problems, andsolutions for Centurion are revised, solved and masterminded. 

 Manufacturing in Centurion expands into two sections: heavymanufacturing and light manufacturing. Light manufacturing takes place in thefour rotating domes, and is underground. Heavy manufacturing, as statedpreviously, takes place in the Telstra HM Center, an exclusive micro-gravitystructure that sustains advantageous heavy manufacturing. Both types ofmanufacturing are needed in Centurion to make it self-reliant and prosperous.With the manufacturing centers, items such as furniture, space shuttles,vehicles and external structures can all be made without the hassle associatedwith imports. 

 Agricultural areas are positioned within the four rotatingdomes and provide an abundant amount of food for Centurion’s people. To savespace, the agricultural farmland, processing and drying volumes are allunderground. Agricultural production is highly mechanized and organized toaugment efficiency, thus increasing the food output. As explained previously,the air composition and temperature of the farmlands suits the conditions at whichspecific plants grow to optimum size and satisfaction. 

 Thereare two research centers in Centurion- a micro-gravity research center and aresearch center with gravity. Research centers are equipped with telescopes,satellite and other communication equipment, and observational machinery. Spaceexploration is easier in space than earth, due to the absence of atmosphere.The micro-gravity research center is between Pegasus Space Port and Telstra HMCenter. The research facility with gravity is located in the administrationsector of Centurion. The research facilities in Centurion promote scientificexperiments with the unique conditions in space, on asteroids, on Mars, and onthe Moon. 

 Entertainment in Centurion is considered a vital aspect.Entertainment structures provide fun for all age groups- from infants andchildren to adults and seniors. Entertainment structures include playgrounds,cinemas, restaurants, video arcades, concert halls, recreational swimmingfacilities and others. Entertainment in micro-gravity includes ‘flying’experiences, and zero-g tennis. The wide range of entertainment options helpssatisfy Centurians, and also attracts tourists.  



 To support the constructionof Centurion, various preliminary objectives have to be instigated. Theseinclude the construction of a fully functional mining and manufacturingfacility on the moon.  The mining facility will provide valuablelunar materials such as aluminum, iron, titanium and oxygen essential inconstructing Centurion. As it is better to have the least amount of transportpossible, lunar materials will be manufactured into structural products onthe moon, before they are ‘launched’ into space with the aid of a constructedmass launcher. Regolith, a key element in the mass shield, will also use themass launcher to transport its heavy weight into space.  Theconstruction of the lunar mining and manufacturing facility before theconstruction of Centurion is necessary, and reduces the time it will take toassemble the space settlement. Only required materials will be moved, so thattransportation and handling costs are mitigated.



Materials Available


High-tech Equipment, Carbon based materials


Iron, Aluminum, Oxygen, Titanium, Regolith, Silicon


Iron, Nitrogen, Sulfur


To transport structures and materials from space toL5, space vehicles and a mass catcher are involved. The space vehicles areshaped in a ‘train-like’ manner and are large. This provides enoughaccommodation for the large amount of materials and products needed in theassembly of Centurion. These ‘space freights’ (figure 18) are the main use of transporting goods, andare separate from space shuttles that transport people. The mass catcher is a‘material collector’, which is the end destination of materials launch by themass launcher. The goods are shot into orbit by the mass launcher (figure 19), and freely travel in space on a straightand directed line. At the end of the journey to L5, the products traveling inspace are caught by a mass catcher and organized, before being sent to variouslocations within Centurion.  

 In starting the construction of Centurion, 12 people will betransported into space. To provide living quarters for the twelve people, arocket fuel container will be refurbished, near a Lower Earth Orbit such as theInternational Space Station. After the fuel container is refurbish, it istransported to L5 in preparation for the construction of Centurion. A usedrocket fuel container is used as a starting habitat because they are alreadypresent, cutting the need for new mini-living quarters. Rocket fuel containersare also relatively basic and user-friendly, and are an ideal living place fora small amount of people (twelve). These 12 people will then commence onworking on the central sphere of Centurion, so as to provide accommodation formore workers. In the construction of Centurion, robotic apparatus are usedheavily to increase efficiency. Many of the robots use are enormous and capableof accomplish a multitude of tasks, just as a modern-day tractor does presently.An example is the robotic arm (figure12), which mounts external structures into place. Construction issignificantly easier due to the absence of gravity, which permits majormovements without excessive energy requirements. 

 Tocommence the construction of Centurion proper, necessary equipments includeexternal structures such as domes, robotic machinery, solar cells, necessarygasses such as carbon, nitrogen and oxygen, and regolith. As the externalstructures are completely assembled, internal structures are added, andatmosphere is created. The phases for the complete construction of Centurion (figure 20) is as shown:  

PHASE 1: The central sphere isassembled in L5 and put into place. Subsequently, regolith is added at the topof the sphere to protect the structure from harmful sunrays. Solar cells areadded near the sphere to provide the needed electricity, and a solar furnacecompilation is begun. After the external structure of the sphere is completed,the internal structures are made to place more people. Atmosphere is thuscreated to provide living conditions. Internal structures that are assembledinclude agricultural areas, sewage, waste and recycling facilities, andatmospheric pumps (although these have already been constructed on the moon).Temporary residential areas are also constructed to provide for the needs ofthe workers. After this, an influx of workers is added, and the building of theTelstra HM Center is embarked. After, similarly to the central sphere, theexternal structure is completed, internal structures are checked, whileatmosphere is created. The solar furnace is accomplished on top of the centralsphere, and solar plants are fixed in both the sphere and the heavy manufacturingcenter. (Note: most necessary constructions are done in the lunar manufacturingcenter. Only assembly and possibly repairing are done in L5)  

PHASE 2: After the central spherecreates enough space for a large amount of workers, spoke assembly iscommenced. The eight spokes are placed with elevators and atmosphere, whilefuture assembling is planned. Meanwhile, the massive regolith tire istransported to L5, and placed in its designated position. Communication andelectricity cables, water and sewage pipes, and robot routes are allconstructed through all spokes. Subsequently, Pegasus Space Port is assembledand fully functioned, as well as its scientific research and tourismcomponents. Mirrors are then implanted around the central sphere to providelight to the planned rotating section of Centurion.   

PHASE 3: The first geodesic dome,Fortunessa, is assembled and placed in its position. The two spokes in thesides of Centurion are connected to the dome, and links are created. Theinternal construction of Fortunessa is then organized and checked, whileatmosphere, climate and weather are all created. Power, water, sewage and othernecessities are introduced in the dome. An addition of 2000 people is set onthe dome.  

PHASE 4: Corresponding to theassembly of Fortunessa, the assembly of Solera is done. Climate, weather andatmosphere are created, while all life necessities (electricity, water, sewage,waste, etc) are implemented. A further 2000 people inhabit the dome.  

PHASE5: Similarto phases 3 and 4, the assembly of the third geodesic dome, Argento, adheres tothe exact operations used for Fortunessa and Solera. The next influx of 2000people, are introduced to their new habitat, Argento.  

PHASE6: Thelast geodesic dome, Kejora, is also assembled and positioned in its rightfulposition. Atmosphere, climate, and weather are created, while energy and waterflows underground, similarly to all other domes. 2000 more people come toCenturion and live in Kejora.  

PHASE7: TheC.S.S Linkway System, comprising of four torus sections, is assembled andconnected to the domes. Atmosphere, weather and climate are created and furtheramounts of people are let to work and live here. The C.B.S (Conveyor BeltSystem) is operated and introduces high-speed inter-Centurian transportation.After this, all constructions and assembly for Centurion is fully completed.The domes and linkways are then rotated with a boost, and artificial gravity isfinally implemented. Subsequently, all people assigned to living in Centurionare transported to the place, and construction is finally accomplished.    



 In areas which have zerogravity, such as Telstra HM Center, Pegasus Space Port, and Centuplex, ways inwhich to move in predictable and safe fashions are necessary. Movement isespecially important for work (such as the manufacturing done in Telstra HMCenter) and transportation (from Pegasus Space Port to Centuplex). To aid inmoving in a micro-gravity environment, restraints and mobility aids are introduced.Examples of mobility aids include tethers and handholds. These two items usemagnetic force to stick to surfaces, similar to how goods are transported underthe Conveyor Belt System. Tethers aid in providing excellent grips for feetonto surfaces, while handholds are similarly used, albeit for hands. These twoitems help people moving around in the micro-gravity areas of Centurion travelaround fairly easily. Without tethers and handholds, mobility would beextremely difficult in non-rotating sections of Centurion. The two items canalso be used in manufacturing processes. Restraints magnetically attach one’sfeet onto the floor, hence making work easier to be accomplished. Restraintsare needed mainly in the heavy manufacturing section, due to the difficulty ofworking when one is moving effortlessly. Control is needed to accomplish manymanufacturing processes, although robots will not be seriously affected by this factor.



 To house 8000 people of different ages, 4800 houses are constructed in thewhole of Centurion. This amount of residential areas provide enough houses for8000 people, as well as a number for further increase in population andemergencies. Houses in Centurion come in a diverse shapes and sizes. Singlepeople generally live in smaller houses or flats, while families live in largerand more complex houses. Houses usually correspond to the guest’s familystatus. Houses in Centurion have a modular approach and are simplistic, in comparisonto present Western houses. The modular approach introduced to Centurian housingeases complicity and makes mass construction dramatically easier. Modularhouses are also generally comfortable, efficient and cheap. All of theseaspects are especially important in Centurion, as space and materials areluxury items. Due to the modular approach applied in residential construction,there are infinite possibilities to the design of houses, although there arefour main shapes: small, rectangular and simple (for singles); large, polygonaland more complex (for families); medium sized, circular and simple (forcouples); and medium sized, polygonal and relatively simple (for more demandingsingles). In general, these four possibilities form the basis of all housingdesigns (figure 22).

 Thedemographics of Centurion are: 45% of Centurion’s population is male, 45% isfemale, 10% children. The age statistic of Centurion is: 10% of Centurion’spopulation is 0 – 20 years old, 75% is 21 – 44 years old, and 15% is over 45years old. Occupation demographics show 45% of Centurion’s workforce as workingin export labor fields, and 30% in internal and support fields. 25% of thepopulation does not belong in any jobs, and are mainly children, mothers, andhandicapped people.  


House Type

Percentage of Total Houses

Large, complex


Medium sized, slightly complex


Small sized, simplistic






 The transportation to, through and from space is afundamental necessity in the process of creating and managing Centurion, aswell as facilitieson asteroids and the moon. For people traveling to Centurion in L5 or thefacilities on the moon, various vehicles need to be used before the destinationarrival. The stages are perspicuously explained in gradual stages (figure 23):  

STAGE 1: People prospecting the visitor stays on Centurion, or any other facilities are transported to the lowerEarth orbit (LEO). Modern day reusable space shuttles (figure 24) are used to accomplish this task, and is aconsiderably expensive process, considering the distance traveled from earth toLEO. This is due to the magnanimous amount of energy required to send a personinto the lower Earth orbit (figure 2). In LEO, spaceshuttles transporting both people and goods are directed to space stationsspecifically built to harbor and re-supply transportation vehicles of allforms. Here, people and goods are transferred to different vehicles, whichleads to the next stage of the captivating journey.  

STAGE 2: At the numerous LEO spacestations, all people and earth-made goods are transferred to space freights andships. Space freights huge, long train-like vehicles used solely for thetransportation of massive amounts of goods. Space ships are used to transportpeople, and are smaller than space freights (but are able to hold 100 - 200people). The space ships and freights are largely automated and computerized,lessening the chance of human errors and accidents. The two vehicles are bothlarge so as to hold a large amount of weight, which is economic. The largesizes are also advantageous in zero gravity, as weight and air resistance areboth eliminated. After all goods and people are transferred to their rightfulships and freights via the space stations, they are immediately transported toCenturion in L5. After approaching Pegasus Space Port in Centurion, the peopleand goods are organized accordingly before being sent to their designatedlocation within Centurion. 

 Forlunar materials and products to be sent to Centurion, the mass launcher is usedat a highly frequent scale. The mass launcher ‘launches’ objects in a straightline towards Centurion using electromagnetic force. This highly efficient modeof transportation for lunar products is ideal for the moon, due to the lack ofa high level of gravity, and the absence of atmosphere. After the productsreach near Centurion, they are stopped by a mass catcher. The mass catcher is anet-like device that pragmatically ‘catches’ lunar products and materials. Theobjects are then organized and sent to Pegasus Space Port with the use of spacefreights, where they are sent to various designated parts of Centurion.External transportation in space is highly mechanized and efficient, as this isa critical factor in supplying organisms with the necessities of life (water,oxygen, food, etc). The less time it takes to transport people to Centurion inspace ships, the less necessities are needed during the transportation.  



 Ashumanity endeavors to complete the challenging tasks of space utilization inthe coming future, Centurion distinctly emboldens a feasible and advantageousduty. The introductions of space settlements and space travel are the nextsteps following organized cities and air travel, as evolution will continue itscertain path towards economic prosperity and technological superiority. Theexploitation of bountiful and valuable space resources clearly will replaceearth’s natural resources, as our race continues to break limitations and fightfor the right to achieve the highest amount of prosperity, peace and safety.The proposed construction and maintenance of the grand space habitat ofCenturion will be the product of a myriad of astronomers, mathematicians,physicists and philosophers of all generations and races from whom space hasbeen pondered upon. In the near future, when space settlements of all sortswill be viable, the uncountable amount of dreams and challenges that have beenrendered in the entire history of mankind will finally be expressed in the solidifiedstate of Centurion. Although the fact that Centurion is the product of theknowledge of countless generations is a major aspect, what makes Centurionextraordinary is something even more extravagant. This aspect is how Centurion,a mere space settlement, will actually materialize the prospects of every humanbeing who has ever dreamt upon living amongst the magical stars that make ouruniverse a truly magnificent and unique place. Centurion - a gateway toeconomic prosperity on earth and exploration of space - will finally be a dreamcome true for all people that have ever lived on earth. Centurion - a cityamidst the shining stars of the Milky Way Galaxy, will finally be a dream cometrue for humanity. 


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Figures1, 2, 5, 17, 19, 23, 24 are taken from:


Allother illustrations, diagrams, charts and tables are personally made.