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Advances in Space Research 52 (2013) 1063–1071

Lakshita – Mining and research hub at L5

Navdeep Sharma ⇑, Aman Mahajan

Department of Physics, Guru Nanak Dev University, Amritsar 143005, Punjab, India

Received 24 August 2012; received in revised form 12 May 2013; accepted 5 June 2013Available online 17 June 2013

Abstract

In this paper, the design of an orbital space settlement named Lakshita located at L5 for 10,000 residents having area of 1 � 106 m2

has been proposed, with the aim of fulfilling mining activities and space research in micro – g. All calculations are made in the perspectiveof a dynamic demography which could lead to the doubling of the population in next 25 years with initial population of 4500. The set-tlement consists of one residential torus, one agricultural torus, industrial cylinder and two docking cylinders rotating coaxially at 1 rpm.2.3% of the total volume of settlement is provided for two docking cylinders with 6 docking ports enabling the elastic flow of space traffic,thereby providing continuous loading and unloading of cargo and passengers. Four pressurized sliding cylinders with 5.7 � 105 m3 vol-ume above the down surface area moving along the spokes fulfill the need of adaptation of visitors at half the gravity level of primarysettlement volumes, as well provide wobble control. 1.1 � 105 torr of pressure is provided above the down surface area of the residentialtorus. The power generation of 400 Mw, required for the functional need of Lakshita, will be obtained through SPS located at L4. The14 h day and 10 h night cycle will be maintained by four mirrors attached on either side from the central cylinder. The walls of the set-tlement will be made up of three consecutive layers of super adobe, Nextel and Kevler-49 respectively to provide radiation and debrisprotection. An assortment of various facilities like appropriate distribution and management of water through an intended network ofpipelines, accurate management of waste within the settlement has been provided.� 2013 COSPAR. Published by Elsevier Ltd. All rights reserved.

Keywords: Space settlement designs; Selection of materials; Sliding cylinders; Expansion plans of settlement; Atmosphere control; Wobble control

1. Introduction

O’Neill in 1976 with the help of NASA Ames ResearchCenter and Stanford University established that big sizespaceships (Neil, 1976) can be constructed to live in space.Then various other scientists proposed different designs inthis field by sketching the Bernal Sphere (Stuart, 1979),Stanford Torus (Johnson and Holbrow, 1975), and O NeillCylinders etc. There is no other place in the Solar Systemwhich duplicates the conditions of earth (Britt, 2001). Butit is mankind’s endeavor to conquer the realms of outerspace and beyond. In 1980, Louis J. Halle, gave his viewpoint that space colonization (Halle, 1980) will protecthuman race at the time of global warfare. NASA Chief,

0273-1177/$36.00 � 2013 COSPAR. Published by Elsevier Ltd. All rights rese

http://dx.doi.org/10.1016/j.asr.2013.06.008

⇑ Corresponding author. Tel.: +91 9814210126.E-mail addresses: navdeep2512@yahoo.co.in (N. Sharma),

dramanmahajan@yahoo.co.in (A. Mahajan).

(Griffin, 2007) has identified space colonization as the vitalgoal of present space flight programs. Space Colonizationwill lead to the solutions of many technological and socio-logical (Siegfried, 2003) problems of our Earth.

The construction material required for such a habitat, iftaken from Earth requires a large amount of energy ascompared to the energy requirements if all the material istaken from space itself. Therefore to construct self sus-tained settlement we would require generating raw materi-als from space itself. Once we build giant solar powersatellites, it will be easy to mine lunar and asteroidsresources (Space Research Associates, 1986). Lunar rego-lith contains Aluminum, Titanium, Iron, Lunar ice etc.which can play a major role in the construction of spacesettlement. Similarly C1 and C2 types of asteroids containhigh quality metal ore, and significant deposits of volatilecompounds, particularly water and are suitable for ourpurposes and will be one of the main sources of building

rved.

Table 1Occupation list of inhabitants.

S. No. Occupation Number

1 Mining and processing 8002 Industrial processing and manufacturing 15003 Scientists 4004 Docking cylinders 5005 Maintenance services 4006 Flight engineers 2007 Software engineers 2008 Business 2009 Administrative and finance 10010 Operations 30011 Civic center 10012 Public domain 20013 Recreation 10014 Children 50015 Transients 500

Table 2Total area required for each segment.

Area/person Total area required [A] (m2)

Residential 100 10,000,00Agricultural 50 50,0000Industrial 30 30,0000

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materials. Most of the near Earth asteroids (NEAs) andmeteorites contain more concentration of platinum groupmetals as compared to earth crust which have applicationsin different areas like: sensors to measure oxygen and NOxlevels, home safety devices to detect carbon monoxide,chemical processing sector, data storage devices, electron-ics applications for electrical conductivity and durability,commercial manufacture of nitric acid, a key ingredientof fertilizers, medical equipments for cancer treatmentand manufacturing of pacemakers etc. Therefore thesematerials are high in demand on Earth as well as in thefuturistic space ventures. If we consider a small nearbyasteroid 3554 AMUN (Lewis, 1996), it has resources con-taining iron, nickel, cobalt and platinum group metals,amounting to about $20 trillion; and there are numerousasteroids to be explored.

O ’Neill analyzed the location and design of the settle-ment as the key feature for its success. The considerationof location includes availability of solar energy, materials,transportation time, etc. Various space settlement designsconsidered different fundamental needs of human survival:e.g. Basic biological requirements, atmosphere, water,food, health, physiological needs, etc. with somewhat dif-ferent approach.

For the better fulfillment of human needs the next gen-eration hybrid designs of space settlement (i.e. composite ofthe basic shapes) Lewis one (Globus, 1991) and many morecame into existence. In 2006 one of the most promisinghybrid designs Kalpana one (Globus et al., 2006) tried toamend various aspects of Lewis one. But rotational rateof this settlement is 2 rpm, which is a compromising valuefrom the point of view of psychological factor as per ONeill’s research of 1975. Structural details, Description oftransportation corridors, dimensional description, andexpansion planning are unanswered by Kalpana One.

The bare minimum three criteria for deciding the loca-tion of the settlement includes propulsion cost, transporta-tion time and station-keeping. Some balance among themis necessary as theses cannot be satisfied altogether. Theproposed settlement is positioned at L5 (Steg and De Vries,1965), since no station keeping (Breakwell et al., 1974) isrequired there. Moreover it provides an easy access toEarth, Moon and NEA’s (one of the necessary require-ments for the mining and construction materials). Thelocation provides unlimited solar energy. The transporta-tion cost of the construction materials will also be reducedas compared to other probable locations (Thomas, 1986).

2. Theoretical background

On comparing the different probable structures like cyl-inder, sphere, torus, dumbbell etc., torus is best suited forresidential purpose for the space working class as it pro-vides non inertial frame of reference. The cylindrical shapedemands more atmospheric volume as compared to torus.The hollow space between the outer wall and the down sur-face will be filled with the lunar regolith (Lindsey, 2003),

thereby shielding the living area from radiations and it fur-ther reduces the mass of the atmosphere required. Theemergency shelters can be constructed under the down sur-face to protect habitants from the unavoidable events likesolar flares. The torus structure is also best suited forexpansion plans. We can weave different torus above andbelow the existing torus for the fulfillment of the futureneeds (approximately 25,000 populations). The final shapecomes out in the form of cylinder and in this way the con-struction cost will be reduced by avoiding the constructionof separate settlement. Another reason for opting the torusis its structural mass. In case of cylindrical structure similarto Kalpana One, the structure mass comes out to be 632 ktfor 3000 persons. On the other hand our proposed designwith 10,000 populations has the structural mass of 550 kt(http://settlement.arc.nasa.gov/designer/sphere.html).Although the shielding mass in torus will always be high,but it can be reduced by segregating agriculture and indus-try as suggested by O’Neil in his NASA summer studies1975. Also on placing the Industrial, research and storagezones inside the central cylinder more volume can beobtained according to requirements for these areas.

The objective of Lakshita will be to act as an on-orbitcenter for refining and zero-g manufacturing. Settlementwill be immediately inhabited upon completion by an ini-tial population of 4,500 people, with an additional tran-sient population of approximately 500 people (divisionshown in Table 1). Considering an annual compoundedgrowth rate of 2.5%, approximately the growth of a largeEarth city such as New Delhi, it will be able to provideenough living area for approximately 10,000 providingfor nearly 25 years of growth.

Table 3Calculations for each segment (Ref – Fig 1).

Formula used Residential torus Agriculture torus

Down surface radius: (r) {Taken by considering the value of g} 900 552Circumference (C) 2pr 5652 m 3467 mWidth (W) A/C 177 m 145 mMinor radius (rm) {assumed close to W/2} 90 m 75 mDistance from center to down surface (rd) [(rm)2 � (w/2)2]½ 16.4 m 19.2 mDown distance (d) [(rm) � (rd)] 73.7 m 55.8 mMajor radius (rmaj) (r � rd) 883.7 m 532.8 mMajor radius circumference (cmaj) 2p(rmaj) 5549.3 m 3346 mDistance till beginning (dbig) rmaj � rm 793.7 m 457.8 mDistance till end (dend) rmaj + rm 973.7 m 607.8 m

Calculations for volumeCos h (W/2)/rm 0.98 0.9667h (rad) Cos�1 10.47 14.84/ 90–h 79.52 75.16Area of sector Asec (P r2

m)2//360 11236.2 m2 7375.1 m2

Area of triangle (o a b) Atri12 rd �W 1446.98 m2 1392 m2

Area of minor segment Amin (Asec � Atri) 9789.2 m2 5983.1 m2

Area of major segment Amaj Pr2m � Amin 15644.8 m2 11679.4 m2

Volume above down surface Amaj � C 8.8 � 107 m3 4.0 � 107 m3

Curved surface area 2prm � C 3.2 � 106 m2 1.6 � 106 m2

Fig. 1. Torus Distance.

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Considering the area required per person as in Table 2and total proposed population (10,000) for whom settle-ment is planned, calculations have been made to find differ-ent structural dimensional parameters and tabulated inTable 3.

We consider the symmetrical and balanced torus struc-ture having center of mass at center (Fig 1) withM1 = M2 (Mass of the left hand system = Mass of righthand system) and X1 = X2 (Initial position of the slidingcylinders along X axis from the center of mass). The varia-tion in mass D m in the settlement results sliding of cylinderfrom their initial position in order to balance the structureto achieve equilibrium condition.

ðMþ DmÞX1 ¼ ðM� DmÞX2 Here X1 –X2

Assuming small variation in mass ¼ ð1þ 2½Dm=M�Þ¼ X2=X1

Thus the relative positions of the sliding cylinders can befound to control wobbling. Similarly the positions for thesliding cylinders along Y axis can be calculated if there isany change in mass occurs along this direction. Also, ifthe dissymmetry of mass occurs in between the X and Y

axis quarter (Figs. 2a and 2b), the shifting of both axialsliding cylinders can be calculated by using parallelogramlaw of vector addition.

3. Proposed design

First of all we need to build a temporary base on lowEarth orbit (LEO) for processing the mined materials forspace settlement construction as materials’ carrying fromEarth is very expensive. We will need to carry only thatmaterial from Earth which cannot be found on Moon, orNEAs. After the programmed robots extend the base for

Fig. 2a. X axis slide.

Fig. 2b. X & Y slide.

Fig. 3. Orthographic View of settlement.

Fig. 4. Dimensional side view.

Fig. 5. Dimensional top view.

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living, the crew consisting of workers, engineers and doc-tors will arrive there in the artificial habitats. In this phasethe required material, i.e. tons of metal and equipment isgathered before any shipment is made. Small materialblocks will be constructed that just need to be assembledfor settlement construction. The construction will start inlower orbit so that planes will be able to distribute thematerial, as unlike space shuttles, they need less fuel andcan carry more equipment and material.

The overall proposed design of Lakshita will constituteouter torus for residential purpose; inner torus for agricul-ture purpose; central cylinder for material processing andrefining; two docking cylinders at the ends of the centralcylinder acting as transportation corridors; four sliding cyl-inders for wobble control and for providing variable g asdepicted in Figs. 3–6. Four reflecting mirrors (Fig 7) willmanage day and night cycle. The spokes attaching thestructure will connect the different parts of the settlement.

The down surface area of the residential torus (177 mwide strip with a ceiling of 106 m) will be of 1 � 106 m2

(Fig 8). The agriculture torus will have down surface areaof 5 � 105 m2 (Ref. Table 4). The artificial gravity of 1 gin residential down surface will be provided by the rotationof the settlement at 1 rpm around the central axis to avoidthe effect of coriolis forces (Hall, 1999, www.artificial-grav-ity.com/sw/SpinCalc/SpinCalc.htm; Hall, 1997). A Gravity

of 6.4 m/s2 on the down surfaces in agricultural torus (bet-ter growth of root system of plants in this gravity) andmicrogravity in central cylinder will be generated at samerotation rate.

Fig. 6. Dimensional cross sectional view.

Fig. 7. Providing natural light inside Lakshita.

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The best use of micro g region is obtained by developingan industrial area in the central cylinder of radius 90 m andheight 360 m approximately 900 m away from residentialtorus. It will contain material processing units like: mag-netic, thermal, electrostatic and electrophoresis separator,glass fabrication, vacuum distillation etc. and storage area.It will also host different facilities like, water storage area,recreation, power production distribution unit, control unitto keep watch on all operations of settlement and observa-tory. Water storage zone can also be used as shelter duringemergency like unusual powerful solar flares for few daysuntil the particles die down.

Fig. 8. Down surface of residential torus.

Two docking cylinders with radius 130 m and height60 m having three ports (one at the top and two on theperiphery) each with radius 40 m will be provided on oppo-site sides of central cylinder. Each port will have a manage-ment center, which will facilitate for the receipt, inspection,assembly, checkout, and storage of all the imports andexports. Warehousing facilities will be provided in dockingcylinders to smoothen the storage and departure. Fuel stor-age will be provided near docking port to enable all-timeadequate supply of fuel. Automated transfer system willtransport fuel in fuel storage containers from docking cyl-inders. It will also host asteroid mapping module, decon-tamination zone, and communication with the miningbase. An emergency repair unit will be located at boththe docking cylinders providing long term docking facilitiesand repairs of ship. Ports are sufficiently separated to pre-vent damage to pressurized volumes. For safety measures;industrial unit can be evacuated and sealed in case ofaccident.

Four sliding cylinders (Fig 9) on the four respectivespokes have been designed to provide wobble control.Varying value of g from 5 m s�2 to 1.5 m s�2 is usable forvisitors and astronaut crew training for long term missionslike Mars and asteroid belt etc. The variable gravity in thecylinders can provide new horizons for the scientists forresearch in the field of human behavior, nanotechnology,bio-medical research, fundamental sciences and spaceexploration.

4. Structural materials

In space there are two main threats to any structure, oneis radiations and other is debris. Residential torus havingcurved surface area 3.2 � 106 m2 needs shielding mass3.2 � 1010 kg to protect it from debris and radiations.Although passive shielding is very effective in obtainingacceptable radiation dosage (less than 0.5 rem/year) andprotection from neutrons exposure and even from meteor-oid’s impacts, but it is too massive. Hence it is not the bestsolution as long time and high expenditure is required tomine so much material from the extra terrestrial sources.We propose hybrid shielding that is active as well as pas-sive, to reduce the structure mass.

We suggest four layered wall made up of Nextel (Chris-tiansen, 2000), Kevler (Joven, 2007), Super adobe (Husain,2007) and Silica aero gel (Gesser and Goswami, 1989) con-secutively. In case of windows Hydrogenous materials andlight elements are expected to be more effective shieldsagainst the Galactic Cosmic Rays (GCR) than alumino sili-cates, which is used in current spacecraft hulls. We proposewindows made up of polyethylene, (Guetersloh et al., 2006)elecrochromic smart glass and fused silicate glass. There willbe three panes of glass, 50 m wide facing towards central cyl-inder. RTV adhesive (Gunn-Golkin, 2005), an electricallyneutral and chemically resistant, will be used to bind differ-ent layers. Natural views of outer space and Earth along withnatural sunlight will be provided by the glass supported by a

Table 4Showing various parameters of structural design of proposed space settlement.

Structuralcomponents{Rotating}

Residentialtorus{Rotating}

Agricultural torus {Rotating} Sliding cylinders Four in

No. {Rotating}Docking cylindersTwo in No. {NonRotating}

Central cylinder {NonRotating}

Major radius (inm)

900 533 65 (radius) 130 (radius) 90 (radius)

Minor radius (inm)

90 75 50 (height) 60 (height) 360 (height)

Down surfacearea (in m2)

1 � 106 0.5 � 106 1.1 � 104 5.3 � 104 Depending on thelevels

Curved surfacearea (in m2)

3.2 � 106 1.6 � 106 1.3 � 104 4.9 � 104 2.0 � 105

Volume abovedown surface(in m3)

8.8 � 107 4.0 � 107 5.7 � 105 3.2 � 106 9.2 � 106

% Volume 62.5 28.3 0.4 2.3 6.5Gravity (m/s�2) 9.8 6.4 1.5–5.0 (Varying

According to radius)

Micro gravity Micro gravity

Primary use Residential andcommercialpurpose

Plantation, animal husbandry,food processing, research &agricultural storage

Temporary stayarrangement, medical &research facilities, etc.

Docking port,storage area,

Industries, industrialstorage zone, controlcenter etc.

Pressurized orunpressurized

Pressurized Pressurized Pressurized Pressurized exceptdocking port &storage area

Pressurized exceptstorage zone

Fig. 9. Sliding cylinder.

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titanium support system. These materials can be obtainedfrom lunar soil (Jarvstrat, 2002) and NEA’s (Kuck, 1979)(Table 5). As windows are turned inward, a significantamount of radiation will be already deflected by the thickshielding for the ring. For active shielding we propose elec-tromagnetic shielding which is considered to be the mostconvenient way to protect the settlement against ionizingradiation (Landis, 1991).

Although above proposed materials for constructionwill provide sufficient protection from small space debris,we propose to have settlement maneuver system similarto the one as attached in international space station to pro-tect settlement (Bedrossian et al., 2007). There will be eightmaneuvers situated symmetrically four on each dockingcylinder capable to orient in order to permit the movementof the settlement in different directions as per requirement.The settlement will be capable to drift by 2–3 km distance,in the combined effect of accelerated and deceleratedmovement.

5. Design considerations

The proposed design considers all psychological require-ments of the residents, like line of sight which is more thanrequired 64 m, large overhead clearance, external views,day and night cycle, contact with external environment atports etc. Silica Aero Gel will be used for sky like paddedsurface inside the settlement. In order to have access to dif-ferent operational units of settlement, central cylinder willbe connected with the four spokes of 50 m each. A circularpassage of diameter 30 m containing four elevators will beprovided in each spoke. Each docking port will have twoelevators which further connects to the elevators of the cen-

tral cylinders. Fig 10 shows transportation corridors in set-tlement describing the road map for export facilities.

The various aspects considered while designing the set-tlement include atmosphere control, thermal control &humidity control, water recycling; water distribution, elec-tricity power generation, day and night provision, rotation& wobble control, psychological aspects, transportationcorridors etc. are described as follows:

The atmosphere of the Lakshita will contain a partialpressure of oxygen sufficient enough to cause the move-ment of oxygen from atmosphere into the alveoli of thelungs (�13.4 k Pa or �100 mmHg) for good respiration.In residential torus volume above the down surface is8.8 � 107 m3, thus by considering the density (q) of theair 1.2 kg m�3 (on the Earth at sea level), the value of pres-sure comes out to be 1.1 � 105 Torr. For preserve suitableliving conditions we have to retain the molar fractions ofthe gasses constant. Earth’s atmosphere consists of: 20%O2, 78% N2, and 2% other gasses (volumes). Number ofmoles of individual gases needed in the atmosphere of res-idential torus can be calculated as: (n) = (P V)/(RT).

Table 5Materials used in different layers, their composition and their sources.

Purpose Material used Composition Used/properties Major source

For makingframework

Titanium High strength Moon

Layers of wallFirst layer

(outermost)Nextel Al, O2 Debris protection due to its high tensile strength Moon

Second layer Kevlar – 49 C, H2 & N2 High tensile strength, shock absorption & Debrisprotection due to inter-molecular hydrogen bond

C from 433- Eros, H2 &N2 from Moon

Third layer Super adobe Regolith Soil compacted into tubes of polytetrafluoroethylene toensure radiation protection.

Lunar soil

Inner most layer Silica aerogel Si, O2, H2 Act as padded surface, thermal insulator, radiationprotection.

Moon

For bondingdifferentlayers

RTV adhesive Si, C, H2, O2 Elecrical, chemical resistant, binds to different materialswithout the use of primers.

Si, H2, O2, from Moon,C from 433- Eros

Layers of windowsFirst layer

(outermost)Polyethylene C, H2 Debris, radiation protection C from 433-Eros, H2

from MoonSecond layer Elecro chromic smart glass

(using super ionic solids)Si, O2 Controls intensity of light Moon

Innermost layer Fused silicate glass Si, O2 Debris, radiation protection MoonMirrors BOPET C, N2, O2 Reflects 97% of light N2, O2, from Moon, C

from 433- Eros

N. Sharma, A. Mahajan / Advances in Space Research 52 (2013) 1063–1071 1069

Where P ¼ Atmospheric pressure ð1 atmÞ

V¼Volume of above the down surface in residential

torus ð8:8�107 m3Þ

T ¼ Temperature of residential torus ðwe consider 25 �CÞ

On calculating n comes out to be 3,596,857,654.36 molof air. Thus number of moles of oxygen is n � 0.2 =719,371,530.87 mol, nitrogen is n � 0.78 = 2,805,548,970.40 mol and of other gases n � 0.02 = 71,937,153.09 mol.

In order to maintain the correct composition, a systemof photo acoustic laser/lamp sensors spaced throughoutthe station that will detect trace gases through spectros-copy. Acidic gases and CO2 will be removed through lith-ium hydroxide filters, while odors and off gassingproducts will be eliminated with activated charcoal,through catalytic oxidation or advanced filtrations. Parti-cles present in the atmosphere will be filtered through ionicgrids. Regeneration of gases from waste collected from dif-ferent processes will take place simultaneously in the plantslocated under the down surface.

Temperature and Humidity Control System [THC]includes control of air-borne particulates and airbornemicroorganisms (Scull et al., 1998). These systems, pro-vided in the residential area, utilize Condensing HeatExchangers [CHX] to remove water obtained throughevaporation, breathing and heat from the residentialatmosphere.

Another major consideration is water. Initially, watercould be obtained by purifying melted ice extracted from

the surface of moon using solar energy. Also, the first cargoships arriving at the location will need to carry water sup-plies. By considering the costs of transportation of waterfrom Moon and/or from Earth, water will be constantlyrecycled inside the settlement. According to the NASA’ssummer study, per person daily requirement of water is31 kg. We assume higher end of water requirement as40 kg and hence 73000 m3 volume of water will be storedin order to fulfill six months requirement of habitats in acluster of interconnected tanks located in the center ofthe space settlement. The residential and agricultural areaswill be provided with two water pumping centers fromwhere water can be supplied. For the distribution of puri-fied water, each house will be connected through pipelinenetwork (Fig 11). Two underground purification plants willalso be provided. Disinfectants will be added to thereclaimed water to prevent the growth of pathogenicorganisms. The Biological Water Processing (BWP) (Kor-tenkamp and Bell, 2003) sub-system will remove organiccompounds. Then the water will be passed to a ReverseOsmosis (RO) subsystem, which will recover 85% of thewater and rest of the 15% will be recovered from Air Evap-oration Subsystem (AES). These two streams of grey waterfrom the RO and the AES will be passed through a Post-Processing Subsystem (PPS) (Pete Bonasso, 2001) to bepurified and make potable water (Ref. Fig 12).

As the system is closed like a loop, it also needs to begoverned by recycling of waste. Different system technolo-gies can be used to deal with wastes like electronic compo-nents, including steel, copper, aluminum and plastics. Fororganic wastes, we suggest an anaerobic digester (http://www.foe.co.uk/resource/briefings/anaerobic_digestion.

Fig. 10. Transportation corridors.

Fig. 11. Water and Sewage Pipe line.

Fig. 12. Flow chart of water recycling.

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pdf) which can be deployed in the agricultural torus. Meth-ane formed as a side product in this digester will be used forhousehold purposes. To manage the inorganic wastesincluding industrial wastes, we suggest a microwave incin-erator or any such system can be used. Pipelines under thedown surface will be provided for the flow of waste and itsbyproducts to their respective sites.

We plan to give a 14 h day and 10 h night to residents ofsettlement by introducing two circular reflecting mirrors at45� and two frustum shaped mirrors made up of BiaxialOriented Polyethylene Terephthalate polyester (BOPT)(Goetz, 2005). It has the potential to reflect up to 97% ofsunlight. To ensure day, two circular mirrors are attachedon either side of the cylinder which will reflect the sunlightonto the frustum shaped mirrors attached at the center ofthe central cylinder and further redirects the sunlight intothe residential & agricultural torus through speciallydesigned windows made up of electro chromic smart glass(Deb, 2000) which will control the intensity of light. Twohelio sensors containing photoreceptor cells will perma-nently determine the position of the Sun towards the mir-rors. By connecting them to the rotation system of themirrors, they will always face the Sun, so that the amountof light reflected onto the torus is at maximum level.

While deciding for the power source we considered theuse of nuclear as well as solar options but given the factthat square meter of space receive almost 7.5 times moresunlight in comparison of Earth and potential risk associ-ated with nuclear energy, solar energy (John, 2010)becomes the first choice for power production. Moreoversolar energy has been chosen over nuclear power due tothe radiation hazards and disposal issues related with

nuclear power. Solar power station (SPS) will be used tomeet the power requirements of settlement. The currentrequirement of energy in U.S.A. (http://en.wikipedia.org/wiki/List_of_countries_by_electricity_consumption) is33KWH per person. Because of the high degree of automa-tion we assumed the requirement to be 40 KWH per per-son, which includes all the residential, agricultural andindustrial needs. Total power requirements of the settle-ment will be 400 MWH. This requirement can be fulfilledby having total solar panel area (http://settle-ment.arc.nasa.gov/designer/sphere.html) of 3.6 � 106 m2

on SPS placed at same vicinity i.e. L5. The power producedcan be transferred to the settlement using microwaves.

In order to ensure constant rotation, Pulsed InductiveThrusters [PIT] (Dailey and Lovberg, 1993) using ammoniaas fuel will be attached in balanced pairs around the struc-ture. The PIT will provide an impulse of 200 times per sec-ond & thrust at the rate of 2.79 N/3350 s by the input of1 MW of power. The wobble control will be required asthe mass distribution changes over time as people andmaterials move about. Its remedy achieved by using themovement of sliding cylinders as shown in the Fig. 5 basedon the principle of the moments. At the time of wobbling,these sliding cylinders will slide in the opposite direction tobalance the structure. The slide distance of these cylinderswill be very less (even less than a meter). Their motion willbe controlled by control unit in the central cylinder.

6. Conclusions

The design ensures the stable and comfortable settle-ment from the structure point of view, operations andhuman factors (area allotted 180 m2 per person and180 m line of sight). Transportation corridors, storage area,water distribution, water recycle, waste disposal are consid-ered while designing the settlement. Two Docking cylindersenable simultaneous docking & loading/unloading of cargo& passenger ships. Two mirrors are placed on either sidesof the central cylinder to provide Day & Night cycle. Selec-tion of materials is done according to the available materi-als on lunar surface and NEAs. The residential torus andthe industrial area are separated from each other onaccount of safety. The agricultural torus between the cen-tral cylinder & residential torus tend to ease the supply of

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food & movement of residents to agricultural torus in caseof any emergency. Future expansion of the settlement canbe done according to the need by constructing anothertorus on the previous torus which will save energy andeconomy instead of designing another separate settlement.Four sliding cylinders move along the spokes to providewobble control as well as to enable the visitors to adapt.Therefore, we can conclude that the proposed design ofspace settlement showed us the path of future into reality.

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