Patent Publication Number: US-11649074-B1

Title: Satellite dispensing system

Description:
BACKGROUND 
     Satellite dispensing systems, such as those stored in and launched by rockets, typically comprise a central mounting structure, to which multiple satellites are individually attached. In this embodiment, the satellites are typically deployed individually or in pairs. Another embodiment includes a vertical stack of satellites, which are collectively clamped to a base structure under the stack. In this embodiment, the satellites are typically deployed en masse. The stacks of satellites can be dispersed via momentum, a propulsion system, or the like, depending on the launch vehicle, dispensing system, or launch plan. 
     Conventional satellite dispensing systems of individually attaching satellites to a central mounting structure tend to be bulky and do not efficiently use physical space within a payload fairing. In addition, because individual separation devices are required for each satellite, a great number of costly separation devices are required in total. 
     Conventional stacked satellite dispensing systems provide a minimal amount of lateral stability to resist forces exerted on the satellite stack in a direction that is perpendicular to a height of the satellite stack. Therefore, the number of satellites within the satellite stack is limited by the inability or limited ability of the satellite stack to resist the lateral inertial forces exerted on the satellite stack. Accordingly, heavier and taller satellite stacks (i.e., satellite stacks with more satellites) cannot be used with current stabilizing systems. 
     Furthermore, conventional stacked-satellite satellite dispensing systems need to release the entire satellite stack at once. This causes the satellites of the satellite stack to be dispensed in single location. Therefore, multiples launches are required to dispense satellites at two separate locations. This can lead to greater cost and lower dispensing efficiency. 
     The art would benefit from a stacked satellite dispensing system that more efficiently withstands forces exerted on the stacked satellite dispensing system, thus allowing the dispenser to carry more satellites. The art would also benefit from a stacked satellite dispensing system that allow satellites to be deployed in batches, rather than all at once. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    illustrates an example stacked satellite dispensing system. 
         FIG.  2    illustrates an example satellite of the example stacked satellite dispensing system. 
         FIGS.  3 A- 3 B  illustrate an example stacked satellite dispensing system. 
         FIG.  4    illustrates example satellites being dispersed from the example stacked satellite dispensing system of  FIGS.  3 A- 3 B . 
     
    
    
     DETAILED DESCRIPTION 
     Stacked satellite dispensing systems and methods are described herein. Aerospace and rocket designers focus on improving the stability of a satellite stack while also minimizing overall structural mass of the rocket. One particular focus for them is to stabilize the satellites of the satellite stack. Designers then need to enhance the stability of the satellite stack itself because the satellite stack can be exposed to a variety of forces during launch, such as high-altitude winds as the launch vehicle passes through earth&#39;s atmosphere into orbit 
     Stacked satellite dispensing systems typically include vertical struts to secure a satellite stack to a base. The vertical struts are jettisoned and the satellites, no longer being secured to the base, are released from the base and disperse into space. The satellites disperse due to momentum of the stacked satellite dispensing system being retained by the satellites once free from the base. Conventional stacked satellite dispensing systems provide a minimal amount of lateral stability to resist forces exerted on the satellite stack in a direction that is perpendicular to a height of the satellite stack. Therefore, the number of satellites within the satellite stack is limited by the inability or limited ability of the satellite stack to resist the forces exerted on the satellite stack. Accordingly, heavier and taller satellite stacks (i.e., satellite stacks with more satellites) cannot be used with current stabilizing systems. 
     Another focus of aerospace and rocket designers is on increasing the number of satellites in the satellite stack, subject to the stability of the satellite stack based on the proposed number of satellites. Therefore, improving the stability of the satellite stack can allow for the addition of more satellites to the satellite stack. The disclosed systems have diagonal struts (i.e., struts extending at an oblique angle) that stabilize satellite stacks horizontally and vertically without adding performance-reducing mass. Rather than stabilizing one or two axes (e.g., one or two of the x-axis, y-axis, and z-axis), the diagonal struts increase stability along all 3 axes (e.g., x-axis, y-axis, and z-axis). The increased stability allows for heavier and taller satellite stacks (i.e., satellite stacks with more total satellites) to be used. 
     Aerospace and rocket designer can also focus on dispensing groups of satellites at different locations in space. This can be done to more evenly dispense satellites or to dispense satellites at distinct locations to reduce the number of required launches, increase dispensing efficiency, reduce cost, or the like. For example, a first group of satellites can be dispensed when the system reaches a first location. Then, a send group of satellites can be dispensed when the system reaches a second location. 
     The improved stability can allow for the satellite stack to be made heavier and taller, such as by having more satellites than a dispensing system with vertical struts. The diagonal struts, which provide the improved stability, can also allow for sub-stacks to be used. The sub-stacks include batches of satellites retained by the stacked satellite dispensing system. Therefore, the stacked satellite dispending system can release single satellites batches at once, rather than all the satellites at once. 
     The diagonal struts can also reduce the number of pyrotechnics incorporated into the satellite stack or dispensing system. Pyrotechnics can be costly, unreliable (i.e., fail to fire), or both. Removing or reducing the number of pyrotechnics can reduce the cost of the satellite stack of dispensing system, improve the reliability of the satellite stack or dispensing, or both. 
       FIG.  1    shows a stacked satellite dispensing system  100 . The stacked satellite dispensing system  100  includes a base  112  and a satellite stack  102 . The base  112  is a platform on which the satellite stack  102  is located or supported. The satellite stack  102  includes columns of satellites  104 , such that each column includes satellites  104  stacked on top of each other. The satellite stack  102  can include any appropriate number of columns (e.g., 1, 2, 3, 4, or more) based on the configuration of the satellites  104 , the total load (i.e., mass or volume) of the satellite stack  102 , the number of satellites  104  to be deployed, the like, or combinations thereof. 
     The stacked satellite dispensing system  100  also includes a first diagonal strut  106   a  and a second diagonal strut  106   b . The first and second diagonal struts  106   a ,  106   b  can extend from the top satellite towards the bottom satellite of the satellite stack  102  or can be adjoined at the top of a cup pillar  108  by a strut coupling  122 , as shown in magnified view  120 . The first and second diagonal struts  106   a ,  106   b  can be adjoined to the strut coupling  122 , such as by an adhesive, by welding, by molding as a single piece, or the like. The strut coupling  122  can include arms, holes, or bores to accept each of the first and second diagonal struts  106   a ,  106   b . The strut coupling  122  can also include a stacking cup to mate the first and second diagonal struts  106   a ,  106   b  to a stacking cup of the top satellite. The stacking cup of the strut coupling  122  can be male, female, or male and female. 
     The first and second diagonal struts  106   a ,  106   b  extend from the strut coupling  122  in different directions towards the base  112 , such as towards a strut bracket  114  at the bottom of an adjacent cup pillar. For example, first and second diagonal struts are connected via a strut coupling at the top of a first cup pillar. The first diagonal strut extends diagonally from the top of the first cup pillar to a strut bracket the bottom of a second cup pillar. The second cup pillar is to the left of the first cup pillar. The second diagonal strut extends diagonally from the top of the first cup pillar to a strut bracket at the bottom of a third cup pillar. The third cup pillar is to the right of the first cup pillar. 
     The satellite stack  102  also includes cup pillars  108 . The satellite stack  102  can include two or more cup pillars based on the number of sides or edges, based on the mass to be supported, or the like. Each cup pillar  108  is formed from stacking cups of all the satellites  104  of the satellite stack  102 . The stacking cups of each cup pillar  108  are coaxial (i.e., having a common axis, such as an axis extending through the stacking cups of the cup pillar  108 ) along a given column or along two columns. The cup pillars  108  can be on an external surface of the satellite stack  102 . For example, a first cup pillar is formed from a first group of coaxial stacking cups of the satellites of the satellite stack  102 . A second cup pillar is formed from a second group of coaxial stacking cups of the satellites of the satellite stack  102 . 
     The satellite stack  102  can also include internal cup pillars that form an internal cavity extending through the satellite stack  102 . 
     The satellite stack  102  also includes stack sidewalls formed by external sidewalls of the satellites  104 . The satellite stack  102  can include two or more stack sidewalls based on satellite design, stack configuration or the like. The external sidewalls forming the stack sidewalls can be coplanar (i.e., the external sidewalls lie on the same plane). The stack sidewalls are formed from sidewalls of multiple satellites which extend between adjacent cup pillars  108 . The stack sidewalls can be traversed by the two diagonal struts, each of the two diagonal struts being from a pair of diagonal struts sharing the same strut coupling  122 . For example, the two diagonal struts traversing the same stack sidewall form an “X,” where the two diagonal struts sharing the same strut coupling form a caret or a hat (e.g., “{circumflex over ( )}”). 
     The satellite dispensing system  100  can also include support rods  110 , which extend between adjacent strut couplings  122 . The support rods  110  can support the satellite stack  102  vertically (i.e., increase force or pressure exerted downwardly on the satellites  104  to inhibit or reduce movement), horizontally (i.e., provide a surface against which the cup pillars  108  can press at a distance furthest from the base  114  to eliminate or reduce any torque due to externally applied forces), or both vertically and horizontally. 
       FIG.  2    shows an example satellite  104 . The satellite  104  is an individual satellite of the satellite stack  102 . Once dispersed or deployed from the satellite stack  102 , the satellite  104  can be part of a satellite constellation (i.e., multiple satellites which form a network), such that each satellite of the satellite constellation can communication with other satellites of the satellite constellation, a ground transceiver, or other satellites and the ground transceiver. The satellite constellation can be used as a communication system, for space observation, Internet or telecommunications service, or the like, with each satellite acting as a node within the network. 
     The satellite  104  includes a main body and stacking cups  204   a - 204   e . The main body includes a housing and components, devices, or systems. The housing can provide a surface to support the components, devices, or systems, or to which the components, devices, or systems can be attached. The housing can also encase or partially encase the components, devices, or systems to protect the components, devices, or systems from external forces or elements. The housing includes a first side  202   a  and a second side  202   b  adjoined by sidewalls, such as sidewalls  206   a - 206   e . The first side  202   a , when in a satellite stack, faces a satellite above or below satellite  104 . The second side  202   b , when in a satellite stack, faces a satellite above or below satellite  104 . When the satellite  104  is a top satellite in the satellite stack, one of the first or second sides  202   a ,  202   b  can face open space or another satellite (e.g., a satellite beneath the satellite  104  in the satellite stack or another satellite from another satellite stack). When the satellite  104  is a bottom satellite in the satellite stack, one of the first or second sides  202   a ,  202   b  can face a base or another satellite (e.g., a satellite on top of the satellite  104  in the satellite stack or another satellite from another satellite stack). 
     The sidewalls, such as sidewalls  206   a - 206   e , can form an external surface of the satellite stack. The sidewalls can also form an internal cavity of the satellite stack, such as when in a circle or circular shape. 
     The components, devices, or systems can include antennas, processors, memory, propulsion system, navigation sensors, proximity detectors, the like, or combinations or multiples thereof. 
     The stacking cups  204   a - 204   e  provide an interface by which adjacent satellites in a satellite stack can be stacked on each other. The stacking cups  204   a - 204   e  can also provide an interface by which the top satellites in each stack or sub-stack can engage with a strut coupling. The stacking cups  204   a - 204   e  can also provide an interface by which the bottom satellites in each stack or sub-stack can engage with a strut bracket or a base. 
     The stacking cups  204   a - 204   e  of the satellite  104  can be male, female, or male and female, such that the adjacent satellites include stacking cups having complementary male or female connections. 
     The stacking cups  204   a - 204   e  can be located on the sidewalls (e.g., sidewalls  206   a - 206   e ) of the satellite  104 , on corners of the satellite formed by adjoining sidewalls (e.g., sidewalls  206   a - 206   e ), or on both sidewalls and corners of the satellite  104 . 
     Though two sidewalls  206   a - 206   e  are discussed herein, the satellite  104  can include 2 or more sidewalls, including 2, 3, 4, 5, 6, or more. The number of sidewalls can be determined based on a design, configuration, or shape of the satellite  104  or the satellite stack. Additionally, though two stacking cups  204   a - 204   e  are discussed herein, the satellite  104  can include 1 or more stacking cups, including, 1, 2, 3, 4, 5, 6, or more. The number of stacking cups  204   a - 204   e  can be determined based on the design, configuration, or shape of the satellite  104  or the satellite stack. 
       FIGS.  3 A- 3 B  show a stacked satellite dispensing system  300 . The stacked satellite dispensing system  300  includes a total satellite stack  302  formed by a first satellite sub-stack  304  and a second satellite sub-stack  310 . The first and second satellite sub-stacks  304 ,  310  include columns of satellites  360 , such that each column includes satellites  360  stacked on top of each other. The first and second satellite sub-stacks  304 ,  310  can include any appropriate number of columns (e.g., 1, 2, 3, 4, or more) based on the configuration of the satellites  360 , the total load (i.e., mass or volume) of the first and second satellite sub-stacks  304 ,  310 , the number of satellites  360  to be deployed, the like, or combinations thereof. The satellites  360  are similar to the satellite  104 . 
     The first and second satellite sub-stacks  304 ,  310  are similar to the satellite stack  202 , except that the first and second satellite sub-stacks  304 ,  310  include cup pillars  308 ,  312 , respectively. Furthermore, the first satellite sub-stack  304  is stacked on top of the second satellite sub-stack  310 . The stacked satellite dispensing system  300  also includes a base  320 , which is a platform on which the second satellite sub-stack  310  is located or supported. 
     The stacked satellite dispensing system  300  includes sub-stack diagonal struts  314   a ,  314   b . The sub-stack diagonal struts  314   a ,  314   b  are similar to the first and second diagonal struts  206   a ,  206   b . The sub-stack diagonal struts  314   a ,  314   b  can extend from the top satellite of the second satellite sub-stack  310  to the bottom satellite of the second satellite sub-stack  310  or can be adjoined at the top of a cup pillar  312  via a sub-stack strut coupling  342 , as shown in magnified view  340 . The sub-stack diagonal struts  314   a ,  314   b  can be adjoined to the sub-stack strut coupling  342 , such as by an adhesive, by welding, by molding as a single piece, or the like. The sub-stack strut coupling  342  can include arms, holes, or bores to accept each of the sub-stack diagonal struts  314   a ,  314   b.    
     The sub-stack diagonal struts  314   a ,  314   b  stabilize the second satellite sub-stack  310  relative to the base  320  via strut brackets  352 . The strut brackets  352  can be attached to or embedded within the base  320 . The strut bracket  352  can be adjoined to the respective diagonal struts (e.g., by an adhesive, by welding, by molding as a single piece, or the like) or the diagonal struts can be inserted into the strut bracket  352  (e.g., such as within arms, holes, or bores). The sub-stack diagonal struts  314   a ,  314   b  traverse an external sidewall of the second sub-stack  310 . The cup pillar  312  of the second satellite sub-stack  310  is similar to the cup pillar  208 . 
     The stacked satellite dispensing system  300  also includes full stack diagonal struts  306   a ,  306   b . The full stack diagonal struts  306   a ,  306   b  stabilize the first and second satellite sub-stacks  304 ,  310  relative to the base  320  via the strut brackets  352 , as shown in magnified view  350 . The full stack diagonal struts  306   a ,  306   b  are similar to the first and second diagonal struts  206   a ,  206   b , except that the full stack diagonal struts  306   a ,  306   b  traverse external sidewalls of the first and second sub-stacks  304 ,  310  (i.e., the full stack  302 ). The full stack diagonal struts  306   a ,  306   b  can extend from the top satellite of the first satellite sub-stack  304  to the bottom satellite of the second satellite sub-stack  310  or can be adjoined at the top of a cup pillar  308  via a full stack strut coupling  332 , as shown in magnified view  330 . The full stack diagonal struts  306   a ,  306   b  can be adjoined to the full stack strut coupling  332 , such as by an adhesive, by welding, by molding as a single piece, or the like. The full stack strut coupling  332  can include arms, holes, or bores to accept each of the full stack diagonal struts  306   a ,  306   b . The cup pillar  308  includes the cup pillar  312  of the second satellite sub-stack  310 , a cup pillar of the first satellite sub-stack  304 , and the strut coupling  342  of the second satellite sub-stack  310 . 
       FIG.  4    shows the satellites  360  being dispersed from the stacked satellite dispensing system  300 . As discussed below, the full stack diagonal struts  306   a ,  306   b  and the sub-stack diagonal struts  316   a ,  316   b  can be moved from locked positions to unlocked positions to allow the satellites  360  of the first sub-stack  304  and the satellites  360  of the second sub-stack  310 , respectively, to be dispersed from the stacked satellite dispensing system  300 . In one example, motors or spring-loaded hinges can used to rotate the strut brackets  352  around an axis on the base  320 , thereby pulling the full stack diagonal struts  306   a ,  306   b  and the sub-stack diagonal struts  316   a ,  316   b  away from the external sidewalls of the first and second sub-stacks  304 ,  310 . In another example, pyrotechnics can be used to jettison the full stack diagonal struts  306   a ,  306   b  and the sub-stack diagonal struts  316   a ,  316   b  from the stacked satellite dispensing system  300 . In yet another example, the full stack diagonal struts  306   a ,  306   b  and the sub-stack diagonal struts  316   a ,  316   b  can be made longer to remove tension from the struts (e.g., telescopically), such as by a motor, by remove or releasing a clamp, latch, or the like. Once the struts are made longer and the tension has been removed, the struts can rotate away from the external sidewall of the first and second sub-stacks  304 ,  310  via the strut brackets or can be jettisoned by separating from the strut brackets. 
     In one example, once the stacked satellite dispensing system  300  reaches a desired trajectory and location in space (e.g., low Earth orbit, which is less an altitude than 2,000 kilometers from the Earth surface), the full stack diagonal struts  306   a ,  306   b  are moved from a locked position to an unlocked position. In another example, once a pre-determined time has been reached or after a certain time has passed since launch, the full stack diagonal struts  306   a ,  306   b  are moved from a locked position to an unlocked position (i.e., based on a pre-programmed schedule). In yet another example, the full stack diagonal struts  306   a ,  306   b  are moved from a locked position to an unlocked position are released manually, such as by a command from an Earth-based controller or a space station controller, whether the controllers are operated by a human or instructed to transmit the command by a processor. The stacked satellite dispensing system  300  can include a communication module (not shown) to communicate with a communication station on Earth or on the space station via Track and Data Relay Satellites (TDRS) or the like. 
     The locked position, as shown in  FIGS.  3 A- 3 B , stabilizes and retains the satellites of the full stack  302  within the stacked satellite dispensing system  300 . The locked position is a position in which the full stack strut coupling  332  is mated with a cup of the top satellite of the full stack  302 . The unlocked position is a position in which the full stack strut coupling  332  is no longer mated with the cup of the top satellite of the full stack  302 . The unlocked position is a position in which the full stack strut coupling  332  is no longer mated with the cup of the top satellite of the full stack  302 . The unlocked position, which no longer stabilizes or restrains the satellites  360 , allows the satellites  360  of the first sub-stack  304  to be dispersed. The satellites  360  can be dispersed by momentum (i.e., the satellites  360  freely float way from the base  320 ), by a deployment device (e.g., a mechanical or pneumatic spring, or the like), by a satellite-based propulsion system, or the like. The satellites  360  of the second-sub stack  310  are still retained in the stacked satellite dispensing system  300  because the sub-stack diagonal struts  316   a ,  316   b  are still in a locked position. 
     Once the satellites  360  of the first sub-stack  302  are dispersed, the stacked satellite dispensing system  300  reaches another desired trajectory or location in space (e.g., low Earth orbit, which is orbit at less than an altitude than 2,000 kilometers from the Earth surface), or both, the sub-stack diagonal struts  316   a ,  316   b  are moved from a locked position to an unlocked position. The locked position, as shown in  FIGS.  3 A- 3 B , stabilizes and retains the satellites of the second sub-stack  310  within the stacked satellite dispensing system  300 . The locked position is a position in which the strut coupling  342  is mated with a cup of the top satellite of the second sub-stack  310 . The unlocked position is a position in which the strut coupling  342  is no longer mated with the cup of the top satellite of the second sub-stack  310 . The unlocked position is a position in which the strut coupling  342  is no longer mated with the cup of the top satellite of the second sub-stack  310 . The unlocked position, which no longer stabilizes or restrains the satellites  360 , allows the satellites  360  of the second sub-stack  310  to be dispersed. The satellites  360  can be dispersed by momentum (i.e., the satellites  360  freely float way from the base  320 ), by a deployment device (e.g., a mechanical or pneumatic spring, or the like), by a satellite-based propulsion system, or the like. 
     The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the disclosure. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the systems and methods described herein. The foregoing descriptions of specific embodiments or examples are presented by way of examples for purposes of illustration and description. They are not intended to be exhaustive of or to limit this disclosure to the precise forms described. Many modifications and variations are possible in view of the above teachings. The embodiments or examples are shown and described in order to best explain the principles of this disclosure and practical applications, to thereby enable others skilled in the art to best utilize this disclosure and various embodiments or examples with various modifications as are suited to the particular use contemplated. It is intended that the scope of this disclosure be defined by the following claims and their equivalents.