Abstract:
A space elevator and method of construction of the same that allows a space elevator to be constructed with a single rocket launch by simultaneously sending cables down to earth and away from earth via a construction satellite. When the earthbound cable reaches the surface, additional cable of gradually increasing cross section is fed from the surface of the earth to finish the construction. The finished space elevator uses moving cables to transport simplified elevator cars into space, thereby greatly increasing the throughput of cargo into space compared to prior art and previous designs.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates to moving goods and people from the surface of the earth to outer space. Currently, all loads sent into space are transported via chemical rockets. Not only do chemical rockets present serious safety concerns with the vast amounts of fuel and oxidizer, but the cost of sending cargo into space via chemical rockets is very expensive. It can cost $5000/kg or more to put cargo into low earth orbit, and $20,000/kg to put cargo into geostationary orbit. 
         [0002]    An alternative to chemical rockets was put forth in 1960 by Yuri Artsutanov with the idea of a space elevator. The mathematical fundamentals for a space elevator were documented in 1975 by Jerome Pearson. However, to date, the limiting factor that has kept a space elevator from being built has been the lack of suitable material with which to build the elevator cable. Yet, recent developments with nanotubes and other allotropes and compounds of carbon or boron indicate that the lack of suitable materials will no longer be a problem in the not-too-distant future. 
         [0003]    Even if suitable cable materials had been available in the past, the prior art and previous designs may still have kept a space elevator from being built. Existing designs have had very high costs for construction, and would not be very practical or economical to operate. Prior art required massive accumulations of materials in space from multiple rocket launches, and the slow build-up of the space elevator by the means of climbers once a “seed” cable has reached the earth. In addition, the throughput of cargo, per year, into space using climbers on a finished space elevator would be low. 
         [0004]    Cable climbers using laser beams as an energy source have become the accepted idea for building and operating a space elevator. In fact, NASA has so thoroughly accepted the idea of space elevator climbers that it has offered a two million dollar prize for a top performing climber with its Elevator 2010 Challenge. 
         [0005]    However, laser powered climbers are, at best, only one or two percent efficient. Therefore 50 to 100 times the actual energy needed would be required each time a climber goes up a space elevator. Also the motors, wheels, and energy conversion equipment for a climber comprise a large portion of the mass of the climber, which limits the cargo capacity. Therefore, the energy requirements for a climber may be 200 times the actual energy needed to take the cargo alone into space. In addition, climbers are inherently slow due to the power requirements and wheel limitations, and so the initial building and the ultimate operation of the space elevator would be slowed by both the speed and the cargo capacity of the climbers. 
         [0006]    Another problem of previous designs is that the incremental cables lifted by the climbers to build the space elevator would always be dragging or sliding against the existing cable. That friction and proximity create a high probability for a snag or tangled cables which would be very difficult to deal with. 
         [0007]    Against this background of problematic designs, the inventor has devised novel solutions which will allow the quick and economical construction of a practical space elevator and will insure its widespread acceptance and use. 
       SUMMARY OF THE INVENTION 
       [0008]    It is therefore the objective of the present invention to provide a novel method and apparatus to quickly transport materials and personnel from the surface of the earth into outer space using substantially less energy and money than has been required heretofore, by means of a practical space elevator. The present invention is a great improvement over prior art for the construction of a space elevator in that it only requires a single rocket launch, regardless of the specific strength of the space elevator cables. All subsequent work is done by feeding cables from the ground. No sliding of cables against cables is ever needed. 
         [0009]    The construction of a space elevator according to the present invention will be faster, simpler and less costly than by using any prior art. Also, the operation of the present invention will allow a higher throughput of cargo to space, a lower energy use, and a faster time to orbit than with any previous space elevator designs. The cables of the present invention would move in a big loop from earth to geostationary orbit, and would provide an almost 100% efficient means of energy transfer. Huge motor/generators on the ground would power loads up the space elevator faster than any prior designs could ever do, and they would regeneratively recoup any energy from slowing down or descending loads. 
         [0010]    The present invention only requires a single rocket launch for construction, and the build-up of the cable strength would be many times faster than could be achieved by climbers. Also, after a space elevator of the present invention was constructed, the throughput of cargo into space per year would be many times greater than a space elevator using climbers. 
         [0011]    For passenger travel into space, the present invention would require almost zero net energy, as the energy expended when the passengers went up would be recouped when they came back down. In addition, the fast transit time through the Van Allen radiation belts would mean less shielding requirements for passenger travel. Cargo into space would generally not come back down, but the elevator car that delivered it would come down, meaning that the net energy expended would only be the actual energy needed to raise the cargo itself. 
         [0012]    The present invention would provide a significant improvement over the prior art in many aspects. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1  is a diagram showing one embodiment of the present invention of a space elevator, with a single moving cable extending from the earth to geostationary orbit; and 
           [0014]      FIG. 2  illustrates a construction satellite used by the present invention in initiating the building of a space elevator; and 
           [0015]      FIG. 3  is a diagram of the construction process for building a space elevator as taught by the present invention; and 
           [0016]      FIG. 4  illustrates a method of lifting a space elevator pulley into space as taught by the present invention; and 
           [0017]      FIG. 5  is a diagram of the present invention of a space elevator composed of multiple loops of moving cables between earth and geostationary orbit; and 
           [0018]      FIG. 6  illustrates the support, connection, and drive mechanism between two pulleys of a space elevator of the present invention with multiple loops; and 
           [0019]      FIG. 7  illustrates the transfer of a space elevator car of the present invention from one loop to another; and 
           [0020]      FIG. 8  is a diagram showing the method of construction of a space elevator of multiple loops as taught by the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0021]    The following description is provided to enable any person skilled in the art to make and use the present invention, and sets forth the best modes contemplated by the inventor for using his invention. Variations to this description however, will be readily apparent to those skilled in the art, since only the generic principles of the present invention have been defined herein. 
         [0022]    Referring now to  FIG. 1 , the space elevator of the present invention includes a pulley  10 , securely fixed to the surface of the earth  11 , at a location near the equator. A belt  12 , is wrapped around pulley  10 , and extends in a great loop from the surface  11  to a second pulley  13 , located in space station  14 , in geostationary orbit. Belt  12  rotates in the direction shown by arrow  15 , and belt  12  is generally kept continually rotating in order that the Coriolis force, from the rotation of the earth, keeps the two opposite sides of the belt apart so that they cannot become entangled. Also located in space station  14  is third pulley  16 , to which second long belt  17  is attached. Belt  17  extends many thousands of kilometers beyond geostationary orbit and ends at a fourth pulley  18 . The rotation of belt  17  is shown by arrow  19 , and is in the same direction as the rotation of belt  12  in order that the Coriolis force also keeps both sides of belt  17  apart. Attached to pulley  18  is a counterweight cable  20 , which extends many thousands of kilometers farther from the earth than pulley  18  and provides the centrifugal force, via the rotation of the earth, to counter the weight of belt  12 , as well as provide initial tension on belt  12 . 
         [0023]    The operation of the present invention, as depicted in  FIG. 1 , is as follows: Regenerative braking motor  21  on pulley  10  stops the rotation of belt  12 , and a load  22  is clamped to the rising side of belt  12 , load  22  having a weight less than the initial tension on one side of belt  12 . As belt  12  is many thousands of kilometers long, and has a significant amount of stretch in it, any acceleration of pulley  10  will not directly transfer motion to lift load  22 . However, as pulley  10  is forced to rotate by motor  21 , that movement takes the tension off of belt  12  in the area  23  between pulley  10  and load  22 , which then allows the tension in belt  12  above load  22  to start lifting load  22 . As pulley  10  accelerates, so will load  22  accelerate until the desired speed of load  22  is achieved. The fact that belt  12  quickly stops to allow load  22  to be attached will not allow the two sides of belt  12  to come together to risk entanglement, due to the fact that the oscillation period of the two sides of belt  12  is measured in hours, due to the extreme length. Therefore, stopping belt  12  long enough to attach or detach loads would only induce slight ripples in the overall path of belt  12 , but would not allow the two sides of belt  12  to get close enough to risk entanglement. 
         [0024]    Continuing with the operation of the present invention, as depicted in  FIG. 1 , load  22  would rise with the rotational movement  15  of belt  12  until it neared space station  14 , at which point braking motor  24 , on pulley  13 , would slow belt  12  to a stop, and load  22  would be unclamped from belt  12 . The cargo of load  22  would then be accessible for unloading at space station  14 . Alternatively, if a lower earth orbit was the final destination of load  22 , then load  22  would be unclamped from belt  12  at a lower altitude. If the final destination of load  22  was an interplanetary location, then load  22  would be transferred and clamped to belt  17  at space station  14 , in like manner as it had been clamped to belt  12  at the surface of the earth. As the distance of load  22  from the earth increased by the movement  19  of belt  17 , the rotation of the earth would cause the tangential velocity of load  22  to increase. When the tangential velocity of load  22 , coupled with the orbital velocity of the earth, was sufficient to reach the desired interplanetary location, load  22  would then be unclamped from belt  17  with the required trajectory. 
         [0025]    The space elevator as depicted in  FIG. 1  can be quickly and easily constructed using a construction satellite  25 , as illustrated in  FIG. 2 . Satellite  25  has two reels of cable, reel  26 , and reel  27 . Each of these reels is rotationally connected to a motor/generator  28  that either drives or brakes the rotation of the respective reel, depending on whether it is operating as a motor or generator. Between reels  26  and  27  is an extendable satellite frame  29 , needed to provide distance between the two reels, so that the extreme tension from cables  30  and  31  will always be very nearly tangential to the reels, with only a very small axial force. In addition, extendable frame  29  is covered by photovoltaic cells to power satellite  25 . Attached to cable  30  is earth-bound load  32 , initially guided by thrusters  33 ; and attached to cable  31 , is counterweight  34 , guided by thrusters  35 . Control centers  36  provide both the electronic controls needed as well as high power resistive elements to dissipate the energy generated by generators  28 . 
         [0026]    The operation of the present invention, as illustrated in  FIG. 2  is a follows: Satellite  25  is placed in geostationary orbit above the desired location of the space elevator base station. Once in that orbit, satellite  25  opens its extendable frame  29  to change from a compact rocket load to the required lengthy satellite. After extending frame  29 , satellite  25  would then orient itself, with cable  30  pointing toward the earth, and cable  31  pointing away from earth. At that point, thrusters  33  on earth-bound load  32  would gently fire, and motor  28  would simultaneously begin to unwind reel  26 , sending load  32  on a trajectory towards earth. At the same time, thrusters  35  on counterweight  34  would fire, and cable  31  from reel  27  would begin to unwind, sending counterweight  34  on a trajectory away from the earth. Once thrusters  33  and  35  got their respective loads up to a modest speed of perhaps 50 m/s, they would no longer be needed. The inertia of load  32  and counterweight  34  would keep them going, and the tangential velocity imparted to cables  30  and  31  by the rotation of their respective reels  26  and  27  would keep load  32  and counterweight  34  moving in their respective directions, with cable following them. 
         [0027]    After a few hundred kilometers of cable were reeled out from reels  26  and  27  the tidal forces would be sufficient to keep the cables aligned with the earth. After a few thousand kilometers were reeled out, motors  28  would have to become generators to hold back the tension created by the gravitational force pulling on load  32  and the centrifugal force pulling on counterweight  34 . 
         [0028]    Incidentally, it would probably be advantageous from an engineering, manufacturing, and operational standpoint to have reels  26  and  27 , with their motor/generators  28 , identical. The mass of counterweight  34  could be easily adjusted so that the necessary length of cable on reel  27  was exactly the same as the length of cable on reel  26 . 
         [0029]    As load  32  and counterweight  34  got farther and farther away from satellite  25 , the center of gravity of the whole system could easily shift away from geostationary orbit, causing satellite  25  to drift with respect to the location of the space elevator ground station on earth. In order to keep the center of gravity at the desired geostationary location, a ground-based station-keeping control center would monitor the position of satellite  25  as cables  30  and  31  were being extended. Signals from that control center would speed up or slow down reels  26  or  27  as needed in order to always maintain the center of gravity in the appropriate geostationary location. 
         [0030]    With load  32  approaching earth, and counterweight  34  approaching its specified distance, the tension on cables  30  and  31  would increase to very high levels, requiring the dissipation of a large amount of energy generated by the generators  28 . In fact, the last few thousand kilometers may require a slowing of the cable speed so as to not exceed the capacity of the generator and the power dissipation resistors. When load  32  arrived at the surface of the earth, it would have expended its propellent, and would just be an empty shell, therefore it would not weigh much. However, it would be brightly colored and carry a transmitter to signal its presence as it got close to the ground. 
         [0031]    After load  32  reached the surface of the earth it would be located and transported to the designated space elevator base station. At that time, the tension on cable  30 , at the surface, would essentially be the weight of the empty shell of load  32 . Load  32  would then be removed from cable  30 , and the reels  26  and  27  of satellite  25  would be locked in place, as the work of satellite  25  would be finished. 
         [0032]    Referring now to  FIG. 3 , cable  38  from reel  37  at the base station on earth  11  would be attached via splice  39  to cable  30 . The tension on cable  30  that was originally supporting load  32  would then start pulling on cable  38 . The cross sectional size of cable  38  would be the same as the size of cable  30 , because even though there would be a little initial tension on cable  30 , that tension would not be sufficient to lift a larger cable very high. As reel  37  began to unwind, the tension on cable  30  would pull up any amount of cable  38  that was unwound, thereby increasing the distance of counterweight  34  from the surface of the earth. That increased distance would increase the tension on cable  30  due to the increased centrifugal force on the counterweight. Also, the additional cable  38  would move disabled satellite  25  to a distance farther out than geostationary orbit  40 , causing satellite  25  to become a counterweight itself. 
         [0033]    The increased tension caused by the increased length of cable  38  can be calculated by knowing the mass of counterweight  34 , the mass of disabled satellite  25 , and the mass per unit length of the cables  30 ,  31 , and  38 . The centrifugal force minus the gravitational force of each segment can be added to determine the net tension in cable  38 . When cable  38  has been extended sufficiently to produce the desired tension level, cable  38  can then be increased in cross sectional area, and fed out towards space. When an appropriate tension level was reached, the more massive cable  38  could then be pulled all the way out to geostationary orbit without the space elevator losing tension, so that more cable  38  could always be pulled up. That same process could then be continued with progressively larger cables. 
         [0034]    Eventually, with enough additional cable  38  fed up from earth, counterweight  34  would get far enough from the surface of the earth that its centrifugal force would exceed the strength of cables  30 ,  31  and the smaller section of cable  38  that support it. However, before these cables were allowed to be overstressed, the mass of counterweight would need to be decreased in order to reduce that centrifugal force. The majority of the mass of counterweight  34  could be in liquid form so that the mass could be gradually released as its distance from the earth increased. However, the time would come when even the empty shell of counterweight  34  would have to be jettisoned. Also, disabled satellite  25  would eventually get far enough from earth that its centrifugal force would require it to be jettisoned also, in order to keep from over-stressing the cables  30  and  38 . 
         [0035]    After counterweight  34 , and satellite  25  were jettisoned, there would only be cables pulling cables into space. There would be no space-based mechanisms, controls, reels, satellites or other devices needed to finish the construction of the space elevator. However, even sections of the cables themselves would have to be jettisoned when they got so far from earth that their centrifugal force began to exceed the allowable stress limit. Those sections of cables could be jettisoned by a designed weak point where the cable would purposely break at a certain point once the stress got to a certain level, or by radio-controlled pyrotechnic devices periodically attached to the rising cable. 
         [0036]    With cables pulling cables, the space elevator could be gradually increased in size until the design requirements of strength and initial tension were met. However, the end result would simply be a single cable extending from earth to over 150,000 km above the earth, not the rotating elevator belts as shown in  FIG. 1 . This would be resolved by pulling the appropriate pulleys into space. 
         [0037]    Referring now to  FIG. 4 , the finished space elevator cable  41  would be attached to the axle  47  of pulley  18 , allowing axle  47  to spin freely, with belt  43  wrapped around pulley  18  and firmly attached to the surface at point  44 . The other end of belt  43  would be fed from reel  45  as cable  41  pulled pulley  18  up into space in direction  46 . As pulley  18  moved upward towards space, belt  43  would be forced to unwind from reel  45  at twice the speed of pulley  18 . That upwards velocity, coupled with the rotation of the earth, would create a Coriolis force  48  on belt  43  that would keep the rising side of belt  43  separated from the stationary side. Pulley  18  would continue to be raised by cable  41  until the distance between the earth and pulley  18  was the same as the distance between pulley  16  and pulley  18  in  FIG. 1 . At that point, the fixed end  44 , of belt  43 , would be spliced to the rising end of belt  43  around pulley  16 , forming belt  17 , as shown in  FIG. 1 . The same process illustrated by  FIG. 4  would then be repeated, with pulley  16  and space station  14  attached to pulley  13 , with the belt material that becomes belt  12  being fed by a large reel similar to reel  45 . When space station  14 , with pulley  13 , arrived at it final location, belt  12  would be spliced together around reel  10 , and the space elevator would be completed. 
         [0038]    In  FIG. 5 , the present invention is diagrammed for a space elevator composed of multiple loops of moving belts between earth and geostationary orbit. This embodiment of the present invention is needed if the specific strength of the belt material is not strong enough to support its own weight between earth and geostationary orbit. An example, with numbers, will be shown for a case where the specific strength of the material is less than 20×10 6  N-m/kg. 
         [0039]    The load on a segment of space elevator cable can be calculated as follows: The gravitational force dF on a section dr of cable of mass λ/m is: 
         [0000]    
       
         
           
             dF 
             = 
             
               
                 
                   GM 
                   e 
                 
                  
                 λ 
                  
                 
                     
                 
                  
                 dr 
               
               
                 r 
                 2 
               
             
           
         
       
     
         [0040]    Where G is the gravitation constant, M e  is the mass of the earth, and r is the distance from the center of the earth. 
         [0041]    If we had a cable stretched from point A to point B, in a radial line above the surface of the earth, there would be a total force from gravity on the cable: 
         [0000]    
       
         
           
             
               
                 
                   F 
                   = 
                   
                     
                       
                         ∫ 
                         A 
                         B 
                       
                        
                       
                         
                           G 
                            
                           
                               
                           
                            
                           
                             M 
                             e 
                           
                            
                           λ 
                            
                           
                               
                           
                            
                           
                              
                             r 
                           
                         
                         
                           r 
                           2 
                         
                       
                     
                      
                     
                         
                     
                     = 
                     
                       
                         
                           G 
                            
                           
                               
                           
                            
                           
                             M 
                             e 
                           
                            
                           λ 
                         
                         A 
                       
                       - 
                       
                         
                           G 
                            
                           
                               
                           
                            
                           
                             M 
                             e 
                           
                            
                           λ 
                         
                         B 
                       
                     
                   
                 
               
               
                 
                   ( 
                   1 
                   ) 
                 
               
             
           
         
       
     
         [0042]    There is also centrifugal force on the cable that tends to counter the gravitational force: 
         [0000]      F=mω 2 r (ω 2 =5.317×10 −9  for the earth&#39;s rotation.)
 
         [0043]    So, for a segment of cable of mass λdr, dF=ω 2 λrdr. Integrating this we get: 
         [0000]    
       
         
           
             
               
                 
                   F 
                   = 
                   
                     
                       
                         ∫ 
                         A 
                         B 
                       
                        
                       
                         
                           ω 
                           2 
                         
                          
                         λ 
                          
                         
                             
                         
                          
                         r 
                          
                         
                            
                           
                               
                           
                            
                           r 
                         
                       
                     
                     = 
                     
                       
                         
                           λ 
                            
                           
                               
                           
                            
                           
                             ω 
                             2 
                           
                            
                           
                             B 
                             2 
                           
                         
                         2 
                       
                        
                       
                           
                       
                       - 
                       
                         
                           
                             λω 
                             2 
                           
                            
                           
                             A 
                             2 
                           
                         
                         2 
                       
                     
                   
                 
               
               
                 
                   ( 
                   2 
                   ) 
                 
               
             
           
         
       
     
         [0044]    Subtracting equation 2 from equation 1, we have the net force on a segment of cable that extends from point A to point B: 
         [0000]    
       
         
           
             
               
                 
                   F 
                   = 
                   
                     
                       
                         
                           G 
                            
                           
                               
                           
                            
                           
                             M 
                             e 
                           
                            
                           λ 
                         
                          
                         
                             
                         
                       
                       A 
                     
                      
                     
                         
                     
                     - 
                     
                       
                         G 
                          
                         
                             
                         
                          
                         
                           M 
                           e 
                         
                          
                         λ 
                       
                       B 
                     
                     - 
                     
                       
                         
                           λω 
                           2 
                         
                          
                         
                           B 
                           2 
                         
                       
                       2 
                     
                     + 
                     
                       
                         
                           λω 
                           2 
                         
                          
                         
                           A 
                           2 
                         
                       
                       2 
                     
                   
                 
               
               
                 
                   ( 
                   3 
                   ) 
                 
               
             
           
         
       
     
         [0045]    Using equation 3 the load on any of the belts of a multiple loop space elevator can be calculated. The calculated loads for the example of a material with a specific strength of less than 20 MN-m/kg are shown in the following description of  FIG. 5 . 
         [0046]    Referring now to  FIG. 5 , a pulley  50 , is attached to the surface of the earth  11 , located at a distance of 6.38 Mm from the center of the earth, around which is wrapped a belt  51 , extending upward to pulley  52 , located 8.7 Mm from the center. This length of belt puts a load of 16.6 MN-m/kg on belt  51  at pulley  52 . Attached to pulley  52  is another pulley,  53 , around which belt  54  is wrapped and extended upward to pulley  55 , at a distance of 11.1 Mm. Belt  54  has twice the cross section of belt  51 . The load on belt  54  is 18.1 Mn-m/kg with its own weight plus the weight of belt  51 . Connected to pulley  55  is another pulley,  56 , around which belt  57  is wrapped and extended up to pulley  58 , located at a distance of 18 Mm. Belt  57  has six times the cross section of belt  51 . The load on belt  57  is 19.3 Mn-m/kg with its own weight plus the weights of belts  54  and  51 . Connected to pulley  58  is another pulley,  59 , around which belt  60  is wrapped and extended up to pulley  61 , located in space station  62 , at a distance of 42.2 Mm, which is the height of geostationary orbit. Belt  60  has eleven times the cross section of belt  51 , The load on belt  60  is 18.7 Mn-m/kg with its own weight plus the weights of belts  57 ,  54  and  51 . Additional belts (not shown) would extend upward from space station  62  to a counterweight cable in order to maintain the appropriate tension in the space elevator. 
         [0047]    The support, connection, and drive mechanism between pulleys  52  and  53  of the present invention is illustrated in  FIG. 6 : A pulley,  63 , is rigidly attached to, and concentric with, pulley  52 , as is pulley  64  attached to, and concentric with, pulley  53 . A similar set of pulleys, not shown, are attached to the back sides of pulleys  52  and  53 . A belt  65  is stretched between pulleys  63  and  64 , and a similar belt  66  is stretched between the pulleys on the back sides of pulleys  52  and  53 . Belts  65  and  66  would serve the multiple purposes of providing the load-carrying support, the bearing surfaces, and the drive system between pulleys  52  and  53 . As belt  51  rotated, the present invention would also cause belt  54  to rotate synchronously with belt  51 . With the other pairs of pulleys of the present invention all having similar configurations, the bottom belt  51  of the present invention would drive all of the other belts of the space elevator. 
         [0048]    Referring now to  FIG. 7 , an elevator car of the present invention is shown crossing over a pair of pulleys of a multiple loop space elevator of the present invention. The elevator car  67  has three clamping mechanisms, shown as  68 ,  69 , and  70 , the distance between adjacent clamps being greater than the distance between pulleys  52  and  53 , and clamping mechanisms  68 ,  69 , and  70  each providing a firm grip to the elevator belts  51  or  54 . Each of the clamping mechanisms  68 ,  69 , and  70  would have a clamp opening  71 , which would allow a pulley, such as pulley  52 , to pass through when in the unclamped state. As car  67 , rising via the movement of belt  51 , approached pulley  52 , belt  51  would slow down, allowing clamping mechanism  68  to unclamp itself from belt  51 . Clamp opening  71  would then allow clamp  68  to pass over pulleys  52  and  53 , where it would then be reclamped to belt  54 . Next, clamp  69  would unclamp from belt  51  and pass over the pulleys  52  and  53  until it could also reclamp on belt  54 . Finally, clamp  70  would follow the same process to transfer itself to belt  54 . With at least two clamps always attached to the belts, elevator car  67  would always be stable and secure as it rode the space elevator past the various pulley pairs. 
         [0049]    The method of construction of a multiple loop space elevator of the present invention, as diagramed in  FIG. 5 , will now be revealed. As the strength of the cable material of a multiple loop space elevator is insufficient for a space elevator to be constructed via the method shown in  FIGS. 2 and 3 , a different construction method is required. An initial construction satellite, analogous to satellite  25  of  FIG. 2 , would feed out multiple belts in the form shown in  FIG. 5 , but with one exception. The exception is that although the ratio of belt sizes would be the same as taught by the present invention of  FIG. 5 , the bottom belt  51  would be replaced by a single cable  72 , as shown in  FIG. 8 , and the belt sizes would be very small compared to the desired finished size. 
         [0050]    Continuing on with  FIG. 8 , cable  72  would initially be lowered to the surface in like manner as was cable  30  in  FIG. 3 , cable  72  also having a small initial tension due to a weight on the end. Cable  72  would then be attached to a new cable  73 , of the same size as cable  72 , via splice  74 , cable  73  being fed from reel  75 . Reel  75  would then feed out additional cable  73 , compelling the entire system to move further out into space, to increase the tension on cable  72 , at pulley  52 , to the maximum allowable tension. When the maximum tension was achieved, cable  72  would be wrapped around capstan  76  on pulley  52 , and clamp  77  would attach the end of cable  72  to belt  54 , which would begin to rise in direction  78 . The slight tension provided on cable  72  by belt  54  would engage the grip of capstan  76 , and cable  72  would begin to rise. The weight of cable  72 , from the earth to the pulleys, would be supported by the grip of capstan  76 , as the necessary additional cable  73  was being fed from reel  75 . Therefore, as cable  72  was lifted up by belt  54 , it would essentially only have to carry the weight of the cable above the capstan. 
         [0051]    As clamp  77 , along with cable  72 , was lifted by belt  54 , it would eventually reach pulley  55 , as seen in  FIG. 5 . At that point, a mechanism would transfer clamp  77  and cable  72  to be wrapped around a capstan on pulley  55 , and then clamp  77  would be reclamped onto belt  57 . Then cable  72  would rise with belt  57 , with the weight of cable  72  between pulleys  55  and  53  being supported by the capstan on pulley  55 . A similar transfer would occur when clamp  77  reached pulleys  58  and  59 , and clamp  77  would reclamp onto belt  60 , which would carry cable  72  all the way up to space station  62  at geostationary orbit. 
         [0052]    As cable  72  initially began to be lifted above the height of pulley  52 , as diagrammed in  FIG. 8 , one side of cable  54  would have more mass than before, and the weight of this mass would decrease the overall tension of the space elevator. With the example given above of a space elevator made of material with less than 20 MN-m/kg of specific strength, the end of cable  72  would only rise about 500 km above the height of pulley  52  until the overall tension had decreased sufficiently that a smaller diameter cable  73  would then be required in order to keep the tension from disappearing completely. In the example given, that reduction in cross section be about 36% of the original size of cable  73 , in order that the end of cable  72  could be lifted all the way to geostationary orbit without losing the overall tension in the space elevator. 
         [0053]    Once cable  72  reached space station  62 , reel  75  would continue to feed out more cable  73 , and cable  72 , followed by cable  73 , would be collected on an empty reel in space station  62 , until a large mass of cable was accumulated on that reel. Because that mass would be in geostationary orbit, it would not affect the overall tension of the space elevator in any way, as all mass in geostationary orbit has its weight perfectly balanced by its centrifugal force. After a sufficient quantity of cable was accumulated in space station  62 , cable  73  would then be cut from the geostationary reel, and the cut end permanently attached to the downward-moving side of belt  60 . At about the same time, the other end produced by the cut in cable  73  would be permanently attached to the upward moving side of the belt extending upwards from space station  62 . Therefore, new cable from the earth, fed by reel  75 , would wrap around belt  60  at the same time that the accumulated cable in station  62  would wrap around the first belt extending above station  62 . Thus both belts would be strengthened at the same time, and in a way that would not adversely affect the overall tension of the space elevator. After belt  60  had been strengthened by multiple wraps of cable  73 , fed from reel  75 , then the end of cable  73  would again be wrapped around the reel in space station  62 , and the reel would again start being filled by more cable  73  from reel  75 . After that reel was sufficiently full again, then cable  73  would be cut again, and the end transferred down to belt  57 , where belt  57  would be strengthened by multiple wraps of cable  73  from reel  75  at the same time that an upper belt, above station  62 , was being wrapped by the cable from the space station reel. A similar process would then be used to strengthen belt  54 , Also, during this entire construction process, the cross section of cable  73  would be increased as often as the overall tension and the load carrying capacity of cable  73  would allow it. 
         [0054]    Therefore, by continuing the above process of wrapping all of the space elevator belts, both above and below space station  62 , the entire space elevator could be strengthened as much as was desired. One of the final steps of the construction process would be changing single cable  73  to belt  51 , as shown in  FIG. 5 , to finish the multiple loop space elevator. 
         [0055]    Those skilled in the art will appreciate that various adaptations and modifications of the invention as described above can be configured without departing from the scope and spirit of the invention. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein.