Modular spacecraft bus system and associated methods

Abstract

The spacecraft bus system described herein includes a propulsion assembly, a top plate assembly, and a bottom plate assembly. Each of the propulsion assembly, the top plate assembly, and the bottom plate assembly is configured to be separately assembled and tested for space environment compatibility. Described herein is a propulsion assembly for use with a spacecraft. The propulsion assembly includes a propellant tank containing propellant therein, at least one thruster, and a frame configured to support the propellant tank and the at least one thruster thereon. The propulsion assembly is configured to be assembled as an individual module and subjected to testing related to space environment compatibility. The frame may be further configured for attachment to other components of the spacecraft after assembly and testing without modification to the propulsion assembly or other components of the spacecraft.

Description

[Technical Field]

[0001] (Commissioned research and development) This invention was made with government support under (state contract name) awarded by (state federal agency name). The government has certain rights in this invention.

[0002] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of U.S. patent application Ser. No. 63 / 439,022, filed Jan. 13, 2023, entitled "Modular Spacecraft Bus System and Associated Methods," and U.S. patent application Ser. No. 18 / 216,571, filed Jun. 29, 2023, entitled "Modular Spacecraft Bus System and Associated Methods," both of which are incorporated herein by reference in their entireties.

[0003] FIELD OF THE INVENTION The present invention relates to spacecraft, and particularly, but not exclusively, to modular spacecraft with improved manufacturability. [Background technology]

[0004] Description of Related Art Current methods of building spacecraft generally involve selecting and producing a propulsion system, and then essentially designing and building the rest of the spacecraft around the propulsion system. Spacecraft capacity and system requirements are highly dependent on the performance specifications of the propulsion system, and therefore, the construction of the spacecraft is customized for the particular combination of the selected propulsion system and other components to be integrated into the spacecraft.

[0005] For example, for a propellant-based propulsion system, the containment and ignition systems for the selected propulsion system are first manufactured and installed in an enclosure, and then the remainder of the spacecraft, such as the guidance and control system, solar panels, and other payloads, are secured inside or around the enclosure. This approach requires that the propulsion system be completed first, which is often the spacecraft component with the longest lead time. In other words, because spacecraft are typically built with the payload integrated into a bus or enclosure, payload details must be captured early in the design process to ensure compatibility between the propulsion system, bus or enclosure, and payload. If there are modifications to the payload after the design is complete, typically at least the spacecraft bus must again be redesigned and customized.

[0006] Also, assembly and testing of the remainder of the spacecraft other than the propulsion system cannot be completed until these remaining components are integrated with the propulsion system. Thus, spacecraft assembly must be performed serially in a set sequence, rather than with various components assembled and tested in parallel. Furthermore, after spacecraft assembly, if there is a problem with the propulsion system or if propellant must be replenished, such a process is difficult to perform once the various components are built around the propulsion system.

[0007] An exemplary spacecraft construction process may involve, for example, the following steps.

[0008] 1) Build a propulsion system

[0009] 2) Test the propulsion system

[0010] 3) Construct an enclosure around the tested propulsion system or install the tested propulsion system within an existing enclosure structure.

[0011] 4) Obtaining client-provided payloads within specific payload guidelines to be compatible with a given propulsion system and enclosure configuration.

[0012] 5) Integrating client-provided payloads into or onto the enclosure structure

[0013] 6) Integrate necessary auxiliary equipment (guidance and control devices, solar panels, antennas, booms, sensing equipment, thrusters, probes, generators, etc.) into or onto the enclosure structure.

[0014] 7) Test the integrated structure (vibration test, thermal test, acoustic test, etc.)

[0015] 8) If the integrated structure has any problems with testing, disassemble the structure, address the problems, reassemble the integrated structure, and then test again.

[0016] Another problem with existing spacecraft systems is that they are typically formed from two or more materials, including specialty materials and / or composite structures. The use of various materials within a single spacecraft can add technical risk, complexity, and cost to a particular spacecraft design. Additionally, composite structures tend to be more difficult to manufacture and therefore may be more prone to containing defects, making them difficult to rework and modify in the short term.

[0017] Therefore, there is a need for improved spacecraft systems that have greater flexibility to accommodate various design changes and improved manufacturability. Summary of the Invention [Means for solving the problem]

[0018] The following presents a simplified summary related to one or more aspects and / or embodiments disclosed herein. As such, the following summary should not be considered an extensive overview related to all contemplated aspects and / or embodiments, nor should the following summary be considered to identify key or critical elements related to all contemplated aspects and / or embodiments or to delineate the scope associated with any particular aspect and / or embodiment. Thus, the following summary is intended only to present certain concepts related to one or more aspects and / or embodiments related to the mechanisms disclosed herein in a simplified form prior to the detailed description presented below.

[0019] In one embodiment, the spacecraft bus system includes a propulsion assembly, a top plate assembly, and a bottom plate assembly, each of which is configured to be separately assembled and independently tested for space environment compatibility.

[0020] In another embodiment, a propulsion assembly for use with a spacecraft includes a propellant tank containing propellant therein, at least one thruster, and a frame configured to support the propellant tank and the at least one thruster thereon. The propulsion assembly is configured to be assembled and subjected to testing related to space environment compatibility as an individual module. Additionally, the frame may be further configured for attachment to other components of the spacecraft after assembly and testing without modification to the propulsion assembly or other components of the spacecraft.

[0021] In one embodiment, the spacecraft bus system includes a propulsion assembly, a top plate assembly, and a bottom plate assembly, each of which is configured to be separately assembled and tested for space environment compatibility.

[0022] In embodiments, the propulsion assembly, the top plate assembly, and the bottom plate assembly are each formed from a single material, hi some embodiments, the single material is aluminum.

[0023] In embodiments, each of the propulsion assembly, the top plate assembly, and the bottom plate assembly is further configured to support at least one component thereon, including a propellant tank, a fuel tank, a thruster, a sensor, an imager, a camera, a robotic arm, a boom arm, navigation equipment, a solar panel, an antenna, a bracket, and a mounting bracket.

[0024] In one embodiment, a propulsion assembly for use with a modular spacecraft system includes a propellant tank containing propellant therein, at least one thruster, and a frame configured to support the propellant tank and the at least one thruster thereon, the propulsion assembly being configured to be assembled as individual modules and subjected to testing related to space environment compatibility.

[0025] In an embodiment, the frame is further configured for attachment to other components of the modular spacecraft system after assembly and testing without modification to the propulsion assembly or other components of the modular spacecraft system, hi some embodiments, the other components include a top plate assembly and a bottom plate assembly.

[0026] In an embodiment, a method for manufacturing a modular spacecraft system is disclosed. The method includes assembling a propulsion assembly, testing the propulsion assembly for space environment compatibility, assembling a top plate assembly, independently testing the top plate assembly for space environment compatibility, assembling a bottom plate assembly, and independently testing the bottom plate assembly for space environment compatibility. The method further includes integrating the propulsion assembly, the top plate assembly, and the bottom plate assembly to form the modular spacecraft system.

[0027] In an embodiment, the method further includes testing the modular spacecraft system so formed for space environment compatibility. In an embodiment, if a problem is found with one of the propulsion assemblies, the top plate assembly, and the bottom plate assembly during testing of the modular spacecraft system so formed, the method further includes identifying the particular one of the propulsion assemblies, the top plate assembly, and the bottom plate assembly having the problem, addressing the problem with the particular one of the propulsion assemblies, the top plate assembly, and the bottom plate assembly, and retesting the particular one of the propulsion assemblies, the top plate assembly, and the bottom plate assembly for space environment compatibility. The method further includes reintegrating the propulsion assemblies, the top plate assembly, and the bottom plate assembly to reform the modular spacecraft system without retesting all of the propulsion assemblies, the top plate assembly, and the bottom plate assembly other than the particular one of the propulsion assemblies, the top plate assembly, and the bottom plate assembly to form the modular spacecraft system.

[0028] These and other features and characteristics of the present technology, as well as the method of operation and function of the associated elements of construction, combination of parts, and economy of manufacture, will become more apparent upon consideration of the following description and the appended claims, with reference to the accompanying drawings, all of which form a part of this specification and in which like reference numerals designate corresponding parts in the various views. It is to be expressly understood, however, that the drawings are for purposes of illustration and description only and are not intended as a definition of the limits of the invention. As used in this specification and the claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. [Brief explanation of the drawings]

[0029] [Figure 1] FIG. 1 illustrates a perspective view of a modular spacecraft system, according to an embodiment.

[0030] [Figure 2] FIG. 2 illustrates an exploded view of the modular spacecraft system of FIG. 1, shown here with the three major assemblies separated to emphasize the modularity of the modular spacecraft system, according to an embodiment.

[0031] [Figure 3] FIG. 3 illustrates a perspective view of an alternative embodiment of a modular spacecraft system.

[0032] [Figure 4] FIG. 4 illustrates an exploded view of the modular spacecraft system of FIG. 3, according to an embodiment.

[0033] [Figure 5A] FIG. 5 illustrates a portion of a process for manufacturing a modular spacecraft system, according to an embodiment. [Figure 5B] FIG. 5 illustrates a portion of a process for manufacturing a modular spacecraft system, according to an embodiment.

[0034] [Figure 6] FIG. 6 illustrates subsequent steps in a process for manufacturing a modular spacecraft system, according to an embodiment.

[0035] For simplicity and clarity of illustration, the drawings depict general modes of construction, and descriptions and details of well-known features and techniques may be omitted to avoid unnecessarily obscuring the embodiments detailed herein. Additionally, elements in the drawings are not necessarily drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve understanding of the described embodiments. The same reference numbers in different figures refer to the same elements.

[0036] The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. In the following detailed description, reference is made to the accompanying drawings, which form a part of this specification, and which are shown by way of illustration or illustrative examples. These aspects may be combined, other aspects may be utilized, and structural changes may be made without departing from the disclosure. The exemplary aspects may be implemented as methods, systems, or devices. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present disclosure is defined by the appended claims and their equivalents. DETAILED DESCRIPTION OF THE INVENTION

[0037] (Detailed Description of the Invention) To address the various problems with current spacecraft design and manufacturing methods discussed above, it would be desirable to be able to design and build a spacecraft such that the different assemblies that form the spacecraft can be built in parallel, tested independently, and then assembled prior to final testing.

[0038] This disclosure describes a modular spacecraft designed for a more efficient manufacturing workflow than currently available. In particular, the design described herein separates the spacecraft layout into multiple major assemblies that can be separately built and independently tested for space environment compatibility, and then integrated to form the final launch vehicle.

[0039] Previous attempts, such as the Modular Common Spacecraft Bus (MCSB) developed by NASA, aimed to enable design modularity for various payloads, but such systems are large and expensive systems designed for a specific propulsion system and configured to accommodate a payload that can fit within the payload module enclosure, rather than being adaptable to various propulsion system and payload configurations. While each of the components and payloads contained within an MCSB can be separately tested for space compatibility and then assembled, many constraints are placed on each component to fit within the MCSB framework. Furthermore, once designed and assembled, the propulsion system, components, and payloads of a given MCSB assembly are difficult to inspect and / or replace, thus further complicating space compatibility certification.

[0040] In one embodiment, the modular design includes an easily manufacturable spacecraft bus that includes three major assemblies that can be separately manufactured and independently tested for space environment compatibility. In one embodiment, one of these major assemblies incorporates the entire propulsion system as a single module / structure that can be built, leak / pressure tested, and then delivered as a complete module ready for integration with other components of the spacecraft.

[0041] 1 illustrates a perspective view of a modular spacecraft system according to an embodiment. As shown in FIG. 1, system 100 includes a propulsion assembly 110, a top plate assembly 120, and a bottom plate assembly 130. Each of propulsion assembly 110, top plate assembly 120, and bottom plate assembly 130 may be constructed separately and then integrated to form system 100.

[0042] 1 , top plate assembly 120 may be bolted onto propulsion assembly 110 via bolts through bolt holes 132. Top plate assembly 120 may include a plurality of openings 140, such as a set of standardized bolt patterns for hosted payloads (e.g., a grid of ¼-20 or M6 holes at 1 inch or 25 mm intervals similar to those used on commercial optical tables). Top plate assembly 120 may also include one or more surfaces 142 and openings 144 for attachment of additional components or payloads, such as, but not limited to, sensors, imagers, cameras, robotic arms, boom arms, navigation equipment, solar panels, antennas, mounting brackets, and other components suitable for use with spacecraft systems such as those commonly used in spacecraft technology. The top plate assembly 120 may further include holes 146 along one or more edges for various purposes, such as, but not limited to, for attachment of additional components to the top plate assembly 120 and / or for ease of lifting and moving the top plate assembly 120 and / or system 100 during assembly, transport, and testing.

[0043] Propulsion assembly 110 may include multiple brackets 150 mounted on legs 152, for example, for attachment of thrusters and other components thereto. Propulsion assembly 110 is configured to support propulsion system 154, for example, by frame 156, which in turn is attached to legs 152. Propulsion system 154 may include components such as propellant or fuel storage tanks, reactor chambers, control systems, connections to thrusters, and other components necessary to provide thrust for maneuvering system 100 in space. Optionally, frame 156 may include multiple openings 158 for attachment of additional components or to serve as pass-throughs. Optionally, propulsion system 154 may also be attached to legs 152 using brackets 160 via mounting portions 162. In an embodiment, mounting portions 162 may be adjustable in length to accommodate various configurations of propulsion systems and brackets. The legs 152 and frame 156 are formed from a sufficiently rigid material to support the propulsion system 154 therein and provide easy access to the propulsion system for space flight.

[0044] The propulsion assembly 110 may include, for example, a propellant tank, one or more thrusters, and a frame for supporting the propellant tank so that the propulsion assembly 110 may be assembled separately and subjected to space environment compatibility testing as an individual module. The tested propulsion assembly may then be integrated with a top plate assembly and a bottom plate assembly, each of which may be assembled and tested separately and independently from the propulsion assembly 110, thus eliminating a major disadvantage of existing spacecraft bus systems that require assembly of the complete spacecraft prior to space environment compatibility testing and / or require components and payloads to be mounted around the propulsion assembly and constrained to specific dimensions that fit within the confines of an outer shell.

[0045] Bottom plate assembly 130 may include multiple openings similar to opening 140 and hole 146, surface 142, and opening 144 on top plate assembly 120. As shown in FIG. 1 , propulsion assembly 110, top plate assembly 120, and bottom plate assembly 130 may be assembled and tested separately, and then simply bolted together to form system 100. In this manner, modifications can be made to various payloads and components attached to any one of the three assemblies without having to redesign the other two assemblies. Furthermore, after system 100 is assembled, additional components, such as a robotic arm and solar panels, that are separately tested for space environment compatibility, can be bolted onto propulsion assembly 110, top plate assembly 120, and bottom plate assembly 130. For example, each of the propulsion assembly 110, the top plate assembly 120, and the bottom plate assembly 130 may include surfaces, openings, bolt holes, and the like for attachment of additional components or payloads such as, but not limited to, propellant tanks, fuel tanks, thrusters, sensors, imagers, cameras, robotic arms, boom arms, navigation equipment, solar panels, antennas, mounting brackets, and other components suitable for use in conjunction with spacecraft systems such as those commonly used in spacecraft technology.

[0046] The top and bottom plate assemblies accommodate various component and payload configurations attached to them without affecting the operation of the propulsion system. Conversely, the propulsion assemblies can be modified without affecting the components and payloads attached to the top plate assembly 120. In other words, unlike previously available spacecraft bus systems, modular spacecraft system 100 can accommodate a much wider range of components and payloads to be attached to them, enabling manufacturability and maintainability not previously available.

[0047] For example, a propulsion system supported within propulsion assembly 110 may be easily replaced without having to disassemble any components supported on either the top or bottom plate assemblies or without having to redesign the entire structure. In an embodiment, enclosure panels (not shown) may be attached to legs 152, frame 156, top plate assembly 120, and / or bottom plate assembly 130 and enclose the propulsion system therein.

[0048] 1 as having a generally octagonal shape, it is noted that this shape can be particularly advantageous in providing structural load paths for strategically distributing loads throughout the modular spacecraft system structure. Other shapes for the upper plate assembly and bottom plate assembly and frame are also contemplated and considered part of this disclosure.

[0049] FIG. 2 illustrates an exploded view 100′ of the modular spacecraft system of FIG. 1 , shown here with the three major assemblies separated to emphasize the modularity of the modular spacecraft system, according to an embodiment. As seen in FIG. 2 , top plate assembly 120 includes a plurality of bolt holes 132 that align with holes 237 on legs 152 of propulsion assembly 110 so that top plate assembly 120 may be secured to propulsion assembly 110 using, for example, bolts. Similarly, bottom plate assembly 130 includes a plurality of holes 270 that align with bolt holes (not visible) formed on the bottom side of legs 152 so that bottom plate assembly 130 may be bolted onto propulsion assembly 110. Additional features, such as snaps, locking mechanisms, and other features to assist in aligning and securing top plate assembly 120 and bottom plate assembly 110, are also contemplated and considered part of this disclosure.

[0050] In one embodiment, system 100, including propulsion assembly 110, top plate assembly 120, bottom plate assembly 130, and various components attached thereto, may be formed from a single material, such as aluminum. The use of a single metal to form the entire system 100 may help ensure that the system will exhibit uniform behavior during testing of the completed system when assembled from the various assemblies after each assembly has been tested independently. While composite structures and materials are often used in spacecraft development due to their favorable strength-to-weight ratio, composite structures cannot be used to integrate payloads into spacecraft late in production because they often require additional system-level testing by the launch provider. Furthermore, composite structures generally cannot be reworked or modified because attachment points are bonded early in the structural fabrication process. An all-aluminum structure as described herein may significantly simplify structural and thermal analysis, manufacturing, assembly, and testing for each assembly and the completed system because aluminum is one of the cheapest and simplest materials to machine. In fact, while composite structures can take 8-12 months to fabricate, aluminum bus structures can be fabricated in a matter of weeks and, if modifications are deemed necessary, can be quickly reworked or adjusted without requiring requalification of the entire structure.

[0051] It is noted that traditionally, metal structures are considered problematic for spacecraft due to the large alignment deviations that can occur due to the higher coefficient of thermal expansion (CTE) associated with metals. Such alignment deviations, in addition to the strength-to-weight ratio, are a consideration for many current spacecraft designs utilizing composite materials. However, the present system design integrates the propulsion assembly, top plate assembly, and bottom plate assembly together using centralized placement of critical directional payloads on the top and bottom plate assemblies with specific attachment points, allowing for an all-metal design without thermal expansion concerns. Also, various cutout configurations and bolt hole arrangements can be used to improve the strength of the spacecraft bus system, as described above. Other materials can also be used to form the modular spacecraft bus of the present disclosure, so long as the materials exhibit suitable structural and material properties and are considered part of the present structure.

[0052] With this modular approach, each of the propulsion assembly 110, the top plate assembly 120, and the bottom assembly 130 can be assembled and tested separately, with various components and / or payloads integrated therewith. That is, the propulsion assembly 110 can be assembled and tested separately from the top plate assembly 120 and the bottom plate assembly 130, and vice versa. For example, this modular design opens up more possibilities for additional hosted payloads to be bolted onto the top plate assembly and then integrated into the spacecraft very late in the production flow.

[0053] Figure 3 illustrates a perspective view of an alternative embodiment of a modular spacecraft system. Some of the components of modular spacecraft system 300 are identical to those illustrated in Figures 1 and 3, although certain aspects of propulsion assembly 310, top plate assembly 320, and bottom plate assembly 330 may be modified relative to their equivalents in modular spacecraft system 100. For example, top plate assembly 310 may include a slightly modified shape of surface 342 or opening 344 compared to surface 142 and opening 144 of Figures 1 and 2, modular spacecraft system 300 may include modified brackets 350 that attach to legs 152, and bottom plate assembly 330 may include a different configuration of bolt holes and other features, thus illustrating the flexibility of modular spacecraft system 300 to accommodate various attachments thereto. Additionally, propulsion assembly 310 includes a modified frame 356 that includes a modified arrangement of openings 358. Openings 358 are configured to provide sufficient structural integrity to support propulsion system 154 while having a reduced weight compared to frame 156 of Figures 1 and 2. Various configurations of frame thickness, width, and opening shapes are contemplated and considered part of this disclosure.

[0054] FIG. 4 illustrates an exploded view 300′ of the modular spacecraft system of FIG. 3 , according to an embodiment. Similar to the embodiment illustrated in FIG. 2 , the exploded view of modular spacecraft system 300 shows various openings, bolt holes, and other features that enable separate assembly and testing of propulsion assembly 310, top plate assembly 320, and bottom plate assembly, each with its own set of attached components and payloads. Then, once the necessary testing and certification of the separate assemblies is completed, the assemblies may be bolted together to form the entire modular spacecraft system. Furthermore, if a problem arises with any component of the modular spacecraft, that particular component may be inspected separately, and / or the assembly associated with that particular component may be separated from the modular spacecraft system, repaired, recertified, and then reinstalled without affecting the other assemblies of the modular spacecraft system.

[0055] Figure 5 illustrates a portion of a process for manufacturing a modular spacecraft system, according to an embodiment. As shown in Figure 5, process 500 begins at start step 501 and then proceeds to step 510, where a propulsion assembly (e.g., propulsion assembly 110 of Figure 1 or propulsion assembly 310 of Figure 3) is assembled. The propulsion assembly so assembled is tested for space compatibility in step 512, and a determination is made in decision 514 whether the propulsion assembly is in fact space compatible. If the determination from decision 514 is "no," process 500 proceeds to step 516, where any issues with the propulsion assembly that render the assembly not space compatible are addressed. Process 500 then returns to step 512, where the propulsion assembly is again tested.

[0056] In parallel or sequentially, process 500 also includes step 520, which assembles a top plate assembly (e.g., top plate assembly 120 of FIG. 1 or top plate assembly 320 of FIG. 3). The so-assembled top plate assembly is tested for space compatibility in step 522, and a determination is made in decision 524 whether the top plate assembly is in fact space compatible. If the determination from decision 524 is "no," process 500 proceeds to step 526, which addresses any issues with the top plate assembly and attempts to bring the top plate assembly into compliance with space compatibility requirements. Process 500 then returns to step 522, where the top plate assembly is again tested.

[0057] Similarly, either in parallel or sequentially, process 500 includes step 530, which assembles a bottom plate assembly (e.g., bottom plate assembly 130 of FIG. 1 or bottom plate assembly 330 of FIG. 3). The so-assembled bottom plate assembly is tested for space compatibility in step 532, and a determination is made in decision 534 whether the bottom plate assembly is in fact space compatible. If the determination from decision 534 is "no," process 500 proceeds to step 536, where any issues with the bottom plate assembly that render the assembly not space compatible are addressed. Process 500 then returns to step 532, where the bottom plate assembly is again tested.

[0058] If the determinations from decisions 514, 524, and 534 are all "yes," process 500 proceeds to step 550 to assemble the modular spacecraft system. Process 500 proceeds to additional steps illustrated in FIG.

[0059] 6 illustrates a continuation of the steps of a process for manufacturing a modular spacecraft system, according to an embodiment. Process 500 continues with decision 610, which determines whether the so-assembled modular spacecraft system is space-qualified as an assembled system in step 550. If decision 610 determines that the assembled modular spacecraft system is, in fact, space-qualified, process 500 is terminated in final step 612.

[0060] If decision 610 determines that the assembled modular spacecraft system is not space-qualified, one or more specific assemblies (e.g., one or more of the propulsion assemblies, the top plate assembly, and the bottom plate assembly) that have issues that deviate from space-qualification are identified. The identified specific assemblies are isolated in step 622. Isolation step 622 may include, for example, partial disassembly of the assembled modular spacecraft system to disengage the specific assemblies from other assemblies that do not have the issues. In step 624, any issues with the specific assemblies are addressed, and then the specific assemblies are tested again in decision 630. If issues with the specific assemblies persist, process 500 returns to step 624 to address the identified issues in repeated attempts.

[0061] If a determination is made in decision 630 that a particular assembly is now space-qualified, the modular spacecraft system is reassembled in step 632, and process 500 returns to decision 610 to again determine whether the assembled modular spacecraft system is now space-qualified. Note that in process 500 of FIGS. 5 and 6, only the particular assembly identified as having a problem is removed, repaired, and retested. That is, unaffected assemblies do not need to be disassembled. This feature is particularly useful in manufacturing systems as complex as modular spacecraft systems. For example, unlike existing spacecraft manufacturing techniques, it is much easier to replace or repair portions of a given assembly (e.g., a top plate assembly, a propulsion assembly, and / or a bottom plate assembly) using the process embodiments described herein.

[0062] Various modifications and variations of the above-described embodiments may be contemplated, and such modifications and variations are considered part of this disclosure. Therefore, the descriptions contained herein are not intended to be limiting. Some contemplated modifications include, but are not limited to, the following:

[0063] 1. While the spacecraft bus system illustrated in Figure 1 is shown as having cubic dimensions, the dimensions of the system may be modified to be more rectangular, cylindrical, pyramidal, tetrahedral, polygonal, and other shapes, for example, to accommodate different types of propellants, improve structural rigidity, and / or allow for hosted payloads of varying shapes and sizes. The system may also be scaled to be compatible with larger or smaller payloads and propulsion systems.

[0064] 2. The components of different assemblies may include one or more cutouts and openings to improve their rigidity, reduce their weight, accommodate the attachment of additional components and payloads of various shapes and sizes, and aid in the transport and manipulation of the assemblies during the construction process.

[0065] 3. While the advantages of an all-aluminum modular spacecraft system are recognized herein, materials other than aluminum may be used for portions of the bus structure to reduce the overall system weight and / or provide improved rigidity.

[0066] 4. Additional features such as bosses, edge curvatures, leg ends, hooks, and interlocking mechanisms may be provided on the propulsion assembly, top plate assembly, or bottom plate assembly to allow stacking of the system onto the launch vehicle.

[0067] 5. One or more components of an assembly in a spacecraft bus system may be formed, for example, by additive manufacturing methods with propulsion lines embedded within the structure of the various components. For example, one or more components may be printed 3D aluminum or composite with propulsion lines embedded therein.

[0068] 6. One or more components of an assembly within a spacecraft bus system may be configured as a foldable structure. For example, a propulsion assembly may include flexible propulsion walls and containment / release mechanisms to allow the propulsion walls to fold or unfold, allowing the propulsion structure to function as a high-pressure propulsion assembly in some situations (e.g., on the ground) and a low-pressure propulsion assembly in other situations (e.g., in orbit). Such a flexible arrangement may allow more vehicles to be launched for a given volume.

[0069] 7. The propulsion assembly may be configured to support a variety of propulsion systems, including monopropellant propulsion, bipropellant propulsion, and electric propulsion.

[0070] As used herein, the recitation of "at least one of A, B, and C" is intended to mean "any of A, B, C, or any combination of A, B, and C." The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments without departing from the spirit or scope of the present disclosure. Thus, the present disclosure is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0071] The terms and expressions employed herein are used as terms and expressions of description, not of limitation, and the use of such terms and expressions is not intended to exclude any equivalents of the shown and described features or portions thereof. Each of the various elements disclosed herein can be achieved in various ways. It should be understood that the present disclosure encompasses each such variation, variations of one embodiment of any apparatus embodiment, method, or process embodiment, or even simply variations of any of these elements. In particular, it should be understood that the words for each element may be expressed by equivalent apparatus or method terms, even if only the function or result is the same. Such equivalent, broader, or even more general terms should be considered to be encompassed in the description of each element or operation. Such terms can be substituted where desired to make explicit the implicitly broad scope to which the present invention is entitled.

[0072] By way of example only, it should be understood that any action can be expressed as a means for taking that action or as an element that causes that action. Similarly, each physical element disclosed should be understood to encompass a disclosure of the action that the physical element facilitates. With regard to this last aspect, by way of example only, a disclosure of a "protrusion" should be understood to encompass a disclosure of the "protruding" action, whether or not explicitly discussed, and conversely, if there is only a disclosure of the "protruding" action, such disclosure should be understood to encompass a disclosure of the "protruding" action. Such variations and alternative terms are to be understood as expressly included within the description.

[0073] (Claims) (Claim 1) A spacecraft bus system, the spacecraft bus system comprising: a propulsion assembly; a top plate assembly; Bottom Plate Assembly and Equipped with The spacecraft bus system, wherein each of the propulsion assembly, the top plate assembly, and the bottom plate assembly is configured to be separately assembled and tested for space environment compatibility. (Claim 2) 10. The spacecraft bus system of claim 1, wherein each of the propulsion assembly, the top plate assembly, and the bottom plate assembly is formed from a single material. (Claim 3) 3. The spacecraft bus system of claim 2, wherein the single material is aluminum. (Claim 4) 10. The spacecraft bus system of claim 1, wherein each of the propulsion assembly, the top plate assembly, and the bottom plate assembly is further configured to support at least one component thereon, the at least one component comprising a propellant tank, a fuel tank, a thruster, a sensor, an imager, a camera, a robotic arm, a boom arm, navigation equipment, a solar panel, an antenna, a bracket, and a mounting bracket. (Claim 5) 1. A propulsion assembly for use in conjunction with a modular spacecraft system, the propulsion assembly comprising: a propellant tank containing a propellant therein; at least one thruster; a frame configured to support the propellant tank and the at least one thruster thereon; and Equipped with The propulsion assembly is configured to be assembled as individual modules and subjected to tests related to space environment compatibility. (Claim 6) 6. The propulsion assembly of claim 5, wherein the frame is further configured for attachment to the propulsion assembly or other components of the modular spacecraft system after assembly and testing without modification to the other components of the modular spacecraft system. (Claim 7) The propulsion assembly of claim 6 , wherein the other components include a top plate assembly and a bottom plate assembly. (Claim 8) 8. The propulsion assembly of claim 7, wherein the other components further include at least one of a sensor, an imager, a camera, a robotic arm, a boom arm, navigation equipment, a solar panel, an antenna, a bracket, and a mounting bracket. (Claim 9) 1. A method for manufacturing a modular spacecraft system, the method comprising: assembling a propulsion assembly; testing the propulsion assembly for space environment compatibility; assembling a top plate assembly; independently testing the top plate assembly for space environment suitability; Assembling a bottom plate assembly; independently testing the bottom plate assembly for space environment suitability; integrating the propulsion assembly, the top plate assembly, and the bottom plate assembly to form the modular spacecraft system; A method comprising: (Claim 10) 10. The method of claim 9, further comprising testing the modular spacecraft system so formed for space environment compatibility. (Claim 11) if during the testing of the modular spacecraft system so formed, a problem is found with one of the propulsion assembly, the top plate assembly, and the bottom plate assembly; identifying a particular one of the propulsion assembly, the top plate assembly, and the bottom plate assembly having the problem; addressing the problem with the particular one of the propulsion assembly, the top plate assembly, and the bottom plate assembly; retesting the particular one of the propulsion assembly, the top plate assembly, and the bottom plate assembly for space environment suitability; reintegrating the propulsion assemblies, the top plate assemblies, and the bottom plate assemblies to re-form the modular spacecraft system without retesting all of the propulsion assemblies, the top plate assemblies, and the bottom plate assemblies other than the particular one of the propulsion assemblies, the top plate assemblies, and the bottom plate assemblies to form the modular spacecraft system; 10. The method of claim 9, further comprising:

[0074] (statement) (Title of Invention) Modular Spacecraft Bus System and Associated Methods (Technical field) (0001) (Commissioned research and development) This invention was made with government support under (state contract name) awarded by (state federal agency name). The government has certain rights in this invention.

[0075] (0002) (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of U.S. patent application Ser. No. 63 / 439,022, filed Jan. 13, 2023, entitled "Modular Spacecraft Bus System and Associated Methods," and U.S. patent application Ser. No. 18 / 216,571, filed Jun. 29, 2023, entitled "Modular Spacecraft Bus System and Associated Methods," both of which are incorporated herein by reference in their entireties.

[0076] (0003) FIELD OF THE INVENTION The present invention relates to spacecraft, and particularly, but not exclusively, to modular spacecraft with improved manufacturability.

[0077] (Background technology) (0004) Description of Related Art Current methods of building spacecraft generally involve selecting and producing a propulsion system, and then essentially designing and building the rest of the spacecraft around the propulsion system. Spacecraft capacity and system requirements are highly dependent on the performance specifications of the propulsion system, and therefore, the construction of the spacecraft is customized for the particular combination of the selected propulsion system and other components to be integrated into the spacecraft.

[0078] (0005) For example, for a propellant-based propulsion system, the containment and ignition systems for the selected propulsion system are first manufactured and installed in an enclosure, and then the remainder of the spacecraft, such as the guidance and control system, solar panels, and other payloads, are secured inside or around the enclosure. This approach requires that the propulsion system be completed first, which is often the spacecraft component with the longest lead time. In other words, because spacecraft are typically built with the payload integrated into a bus or enclosure, payload details must be captured early in the design process to ensure compatibility between the propulsion system, bus or enclosure, and payload. If there are modifications to the payload after the design is complete, typically at least the spacecraft bus must again be redesigned and customized.

[0079] (0006) Also, assembly and testing of the remainder of the spacecraft other than the propulsion system cannot be completed until these remaining components are integrated with the propulsion system. Thus, spacecraft assembly must be performed serially in a set sequence, rather than with various components assembled and tested in parallel. Furthermore, after spacecraft assembly, if there is a problem with the propulsion system or if propellant must be replenished, such a process is difficult to perform once the various components are built around the propulsion system.

[0080] (0007) An exemplary spacecraft construction process may involve, for example, the following steps.

[0081] (0008) 1) Build a propulsion system

[0082] (0009) 2) Test the propulsion system

[0083] (0010) 3) Construct an enclosure around the tested propulsion system or install the tested propulsion system within an existing enclosure structure.

[0084] (0011) 4) Obtaining client-provided payloads within specific payload guidelines to be compatible with a given propulsion system and enclosure configuration.

[0085] (0012) 5) Integrating client-provided payloads into or onto the enclosure structure

[0086] (0013) 6) Integrate necessary auxiliary equipment (guidance and control devices, solar panels, antennas, booms, sensing equipment, thrusters, probes, generators, etc.) into or onto the enclosure structure.

[0087] (0014) 7) Test the integrated structure (vibration test, thermal test, acoustic test, etc.)

[0088] (0015) 8) If the integrated structure has any problems with testing, disassemble the structure, address the problems, reassemble the integrated structure, and then test again.

[0089] (0016) Another problem with existing spacecraft systems is that they are typically formed from two or more materials, including specialty materials and / or composite structures. The use of various materials within a single spacecraft can add technical risk, complexity, and cost to a particular spacecraft design. Additionally, composite structures tend to be more difficult to manufacture and therefore may be more prone to containing defects, making them difficult to rework and modify in the short term.

[0090] (0017) Therefore, there is a need for improved spacecraft systems that have greater flexibility to accommodate various design changes and improved manufacturability.

[0091] (Summary of the Invention) (Means for solving the problem) (0018) The following presents a simplified summary related to one or more aspects and / or embodiments disclosed herein. As such, the following summary should not be considered an extensive overview related to all contemplated aspects and / or embodiments, nor should the following summary be considered to identify key or critical elements related to all contemplated aspects and / or embodiments or to delineate the scope associated with any particular aspect and / or embodiment. Thus, the following summary is intended only to present certain concepts related to one or more aspects and / or embodiments related to the mechanisms disclosed herein in a simplified form prior to the detailed description presented below.

[0092] (0019) In one embodiment, the spacecraft bus system includes a propulsion assembly, a top plate assembly, and a bottom plate assembly, each of which is configured to be separately assembled and independently tested for space environment compatibility.

[0093] (0020) In another embodiment, a propulsion assembly for use with a spacecraft includes a propellant tank containing propellant therein, at least one thruster, and a frame configured to support the propellant tank and the at least one thruster thereon. The propulsion assembly is configured to be assembled and subjected to testing related to space environment compatibility as an individual module. Additionally, the frame may be further configured for attachment to other components of the spacecraft after assembly and testing without modification to the propulsion assembly or other components of the spacecraft.

[0094] (0021) In one embodiment, the spacecraft bus system includes a propulsion assembly, a top plate assembly, and a bottom plate assembly, each of which is configured to be separately assembled and tested for space environment compatibility.

[0095] (0022) In embodiments, the propulsion assembly, the top plate assembly, and the bottom plate assembly are each formed from a single material, hi some embodiments, the single material is aluminum.

[0096] (0023) In embodiments, each of the propulsion assembly, the top plate assembly, and the bottom plate assembly is further configured to support at least one component thereon, including a propellant tank, a fuel tank, a thruster, a sensor, an imager, a camera, a robotic arm, a boom arm, navigation equipment, a solar panel, an antenna, a bracket, and a mounting bracket.

[0097] (0024) In one embodiment, a propulsion assembly for use with a modular spacecraft system includes a propellant tank containing propellant therein, at least one thruster, and a frame configured to support the propellant tank and the at least one thruster thereon, the propulsion assembly being configured to be assembled as individual modules and subjected to testing related to space environment compatibility.

[0098] (0025) In an embodiment, the frame is further configured for attachment to other components of the modular spacecraft system after assembly and testing without modification to the propulsion assembly or other components of the modular spacecraft system, hi some embodiments, the other components include a top plate assembly and a bottom plate assembly.

[0099] (0026) In an embodiment, a method for manufacturing a modular spacecraft system is disclosed. The method includes assembling a propulsion assembly, testing the propulsion assembly for space environment compatibility, assembling a top plate assembly, independently testing the top plate assembly for space environment compatibility, assembling a bottom plate assembly, and independently testing the bottom plate assembly for space environment compatibility. The method further includes integrating the propulsion assembly, the top plate assembly, and the bottom plate assembly to form the modular spacecraft system.

[0100] (0027) In an embodiment, the method further includes testing the modular spacecraft system so formed for space environment compatibility. In an embodiment, if a problem is found with one of the propulsion assemblies, the top plate assembly, and the bottom plate assembly during testing of the modular spacecraft system so formed, the method further includes identifying the particular one of the propulsion assemblies, the top plate assembly, and the bottom plate assembly having the problem, addressing the problem with the particular one of the propulsion assemblies, the top plate assembly, and the bottom plate assembly, and retesting the particular one of the propulsion assemblies, the top plate assembly, and the bottom plate assembly for space environment compatibility. The method further includes reintegrating the propulsion assemblies, the top plate assembly, and the bottom plate assembly to reform the modular spacecraft system without retesting all of the propulsion assemblies, the top plate assembly, and the bottom plate assembly other than the particular one of the propulsion assemblies, the top plate assembly, and the bottom plate assembly to form the modular spacecraft system.

[0101] (0028) These and other features and characteristics of the present technology, as well as the method of operation and function of the associated elements of construction, combination of parts, and economy of manufacture, will become more apparent upon consideration of the following description and the appended claims, with reference to the accompanying drawings, all of which form a part of this specification and in which like reference numerals designate corresponding parts in the various views. It is to be expressly understood, however, that the drawings are for purposes of illustration and description only and are not intended as a definition of the limits of the invention. As used in this specification and the claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0102] BRIEF DESCRIPTION OF THE DRAWINGS (0029) FIG. 1 illustrates a perspective view of a modular spacecraft system, according to an embodiment.

[0103] (0030) FIG. 2 illustrates an exploded view of the modular spacecraft system of FIG. 1, shown here with the three major assemblies separated to emphasize the modularity of the modular spacecraft system, according to one embodiment.

[0104] (0031) FIG. 3 illustrates a perspective view of an alternative embodiment of a modular spacecraft system.

[0105] (0032) FIG. 4 illustrates an exploded view of the modular spacecraft system of FIG. 3, according to an embodiment.

[0106] (0033) FIG. 5 illustrates a portion of a process for manufacturing a modular spacecraft system, according to an embodiment.

[0107] (0034) FIG. 6 shows subsequent steps in a process for manufacturing a modular spacecraft system, according to an embodiment.

[0108] (0035) For simplicity and clarity of illustration, the drawings depict general modes of construction, and descriptions and details of well-known features and techniques may be omitted to avoid unnecessarily obscuring the embodiments detailed herein. Additionally, elements in the drawings are not necessarily drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve understanding of the described embodiments. The same reference numbers in different figures refer to the same elements.

[0109] (0036) The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. In the following detailed description, reference is made to the accompanying drawings, which form a part of this specification, and which are shown by way of illustration or illustrative examples. These aspects may be combined, other aspects may be utilized, and structural changes may be made without departing from the disclosure. The exemplary aspects may be implemented as methods, systems, or devices. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present disclosure is defined by the appended claims and their equivalents.

[0110] (Mode for Carrying Out the Invention) (0037) (Detailed Description of the Invention) To address the various problems with current spacecraft design and manufacturing methods discussed above, it would be desirable to be able to design and build a spacecraft such that the different assemblies that form the spacecraft can be built in parallel, tested independently, and then assembled prior to final testing.

[0111] (0038) This disclosure describes a modular spacecraft designed for a more efficient manufacturing workflow than currently available. In particular, the design described herein separates the spacecraft layout into multiple major assemblies that can be separately built and independently tested for space environment compatibility, and then integrated to form the final launch vehicle.

[0112] (0039) Previous attempts, such as the Modular Common Spacecraft Bus (MCSB) developed by NASA, aimed to enable design modularity for various payloads, but such systems are large and expensive systems designed for a specific propulsion system and configured to accommodate a payload that can fit within the payload module enclosure, rather than being adaptable to various propulsion system and payload configurations. While each of the components and payloads contained within an MCSB can be separately tested for space compatibility and then assembled, many constraints are placed on each component to fit within the MCSB framework. Furthermore, once designed and assembled, the propulsion system, components, and payloads of a given MCSB assembly are difficult to inspect and / or replace, thus further complicating space compatibility certification.

[0113] (0040) In one embodiment, the modular design includes an easily manufacturable spacecraft bus that includes three major assemblies that can be separately manufactured and independently tested for space environment compatibility. In one embodiment, one of these major assemblies incorporates the entire propulsion system as a single module / structure that can be built, leak / pressure tested, and then delivered as a complete module ready for integration with other components of the spacecraft.

[0114] (0041) 1 illustrates a perspective view of a modular spacecraft system according to an embodiment. As shown in FIG. 1, system 100 includes a propulsion assembly 110, a top plate assembly 120, and a bottom plate assembly 130. Each of propulsion assembly 110, top plate assembly 120, and bottom plate assembly 130 may be constructed separately and then integrated to form system 100.

[0115] (0042) 1 , top plate assembly 120 may be bolted onto propulsion assembly 110 via bolts through bolt holes 132. Top plate assembly 120 may include a plurality of openings 140, such as a set of standardized bolt patterns for hosted payloads (e.g., a grid of ¼-20 or M6 holes at 1 inch or 25 mm intervals similar to those used on commercial optical tables). Top plate assembly 120 may also include one or more surfaces 142 and openings 144 for attachment of additional components or payloads, such as, but not limited to, sensors, imagers, cameras, robotic arms, boom arms, navigation equipment, solar panels, antennas, mounting brackets, and other components suitable for use with spacecraft systems such as those commonly used in spacecraft technology. The top plate assembly 120 may further include holes 146 along one or more edges for various purposes, such as, but not limited to, for attachment of additional components to the top plate assembly 120 and / or for ease of lifting and moving the top plate assembly 120 and / or system 100 during assembly, transport, and testing.

[0116] (0043) Propulsion assembly 110 may include multiple brackets 150 mounted on legs 152, for example, for attachment of thrusters and other components thereto. Propulsion assembly 110 is configured to support propulsion system 154, for example, by frame 156, which in turn is attached to legs 152. Propulsion system 154 may include components such as propellant or fuel storage tanks, reactor chambers, control systems, connections to thrusters, and other components necessary to provide thrust for maneuvering system 100 in space. Optionally, frame 156 may include multiple openings 158 for attachment of additional components or to serve as pass-throughs. Optionally, propulsion system 154 may also be attached to legs 152 using brackets 160 via mounting portions 162. In an embodiment, mounting portions 162 may be adjustable in length to accommodate various configurations of propulsion systems and brackets. The legs 152 and frame 156 are formed from a sufficiently rigid material to support the propulsion system 154 therein and provide easy access to the propulsion system for space flight.

[0117] (0044) The propulsion assembly 110 may include, for example, a propellant tank, one or more thrusters, and a frame for supporting the propellant tank so that the propulsion assembly 110 may be assembled separately and subjected to space environment compatibility testing as an individual module. The tested propulsion assembly may then be integrated with a top plate assembly and a bottom plate assembly, each of which may be assembled and tested separately and independently from the propulsion assembly 110, thus eliminating a major disadvantage of existing spacecraft bus systems that require assembly of the complete spacecraft prior to space environment compatibility testing and / or require components and payloads to be mounted around the propulsion assembly and constrained to specific dimensions that fit within the confines of an outer shell.

[0118] (0045) Bottom plate assembly 130 may include multiple openings similar to opening 140 and hole 146, surface 142, and opening 144 on top plate assembly 120. As shown in FIG. 1 , propulsion assembly 110, top plate assembly 120, and bottom plate assembly 130 may be assembled and tested separately, and then simply bolted together to form system 100. In this manner, modifications can be made to various payloads and components attached to any one of the three assemblies without having to redesign the other two assemblies. Furthermore, after system 100 is assembled, additional components, such as a robotic arm and solar panels, that are separately tested for space environment compatibility, can be bolted onto propulsion assembly 110, top plate assembly 120, and bottom plate assembly 130. For example, each of the propulsion assembly 110, the top plate assembly 120, and the bottom plate assembly 130 may include surfaces, openings, bolt holes, and the like for attachment of additional components or payloads such as, but not limited to, propellant tanks, fuel tanks, thrusters, sensors, imagers, cameras, robotic arms, boom arms, navigation equipment, solar panels, antennas, mounting brackets, and other components suitable for use in conjunction with spacecraft systems such as those commonly used in spacecraft technology.

[0119] (0046) The top and bottom plate assemblies accommodate various component and payload configurations attached to them without affecting the operation of the propulsion system. Conversely, the propulsion assemblies can be modified without affecting the components and payloads attached to the top plate assembly 120. In other words, unlike previously available spacecraft bus systems, modular spacecraft system 100 can accommodate a much wider range of components and payloads to be attached to them, enabling manufacturability and maintainability not previously available.

[0120] (0047) For example, a propulsion system supported within propulsion assembly 110 may be easily replaced without having to disassemble any components supported on either the top or bottom plate assemblies or without having to redesign the entire structure. In an embodiment, enclosure panels (not shown) may be attached to legs 152, frame 156, top plate assembly 120, and / or bottom plate assembly 130 and enclose the propulsion system therein.

[0121] (0048) 1 as having a generally octagonal shape, it is noted that this shape can be particularly advantageous in providing structural load paths for strategically distributing loads throughout the modular spacecraft system structure. Other shapes for the upper plate assembly and bottom plate assembly and frame are also contemplated and considered part of this disclosure.

[0122] (0049) FIG. 2 illustrates an exploded view 100′ of the modular spacecraft system of FIG. 1 , shown here with the three major assemblies separated to emphasize the modularity of the modular spacecraft system, according to an embodiment. As seen in FIG. 2 , top plate assembly 120 includes a plurality of bolt holes 132 that align with holes 237 on legs 152 of propulsion assembly 110 so that top plate assembly 120 may be secured to propulsion assembly 110 using, for example, bolts. Similarly, bottom plate assembly 130 includes a plurality of holes 270 that align with bolt holes (not visible) formed on the bottom side of legs 152 so that bottom plate assembly 130 may be bolted onto propulsion assembly 110. Additional features, such as snaps, locking mechanisms, and other features to assist in aligning and securing top plate assembly 120 and bottom plate assembly 110, are also contemplated and considered part of this disclosure.

[0123] (0050) In one embodiment, system 100, including propulsion assembly 110, top plate assembly 120, bottom plate assembly 130, and various components attached thereto, may be formed from a single material, such as aluminum. The use of a single metal to form the entire system 100 may help ensure that the system will exhibit uniform behavior during testing of the completed system when assembled from the various assemblies after each assembly has been tested independently. While composite structures and materials are often used in spacecraft development due to their favorable strength-to-weight ratio, composite structures cannot be used to integrate payloads into spacecraft late in production because they often require additional system-level testing by the launch provider. Furthermore, composite structures generally cannot be reworked or modified because attachment points are bonded early in the structural fabrication process. An all-aluminum structure as described herein may significantly simplify structural and thermal analysis, manufacturing, assembly, and testing for each assembly and the completed system because aluminum is one of the cheapest and simplest materials to machine. In fact, while composite structures can take 8-12 months to fabricate, aluminum bus structures can be fabricated in a matter of weeks and, if modifications are deemed necessary, can be quickly reworked or adjusted without requiring requalification of the entire structure.

[0124] (0051) It is noted that traditionally, metal structures are considered problematic for spacecraft due to the large alignment deviations that can occur due to the higher coefficient of thermal expansion (CTE) associated with metals. Such alignment deviations, in addition to the strength-to-weight ratio, are a consideration for many current spacecraft designs utilizing composite materials. However, the present system design integrates the propulsion assembly, top plate assembly, and bottom plate assembly together using centralized placement of critical directional payloads on the top and bottom plate assemblies with specific attachment points, allowing for an all-metal design without thermal expansion concerns. Also, various cutout configurations and bolt hole arrangements can be used to improve the strength of the spacecraft bus system, as described above. Other materials can also be used to form the modular spacecraft bus of the present disclosure, so long as the materials exhibit suitable structural and material properties and are considered part of the present structure.

[0125] (0052) With this modular approach, each of the propulsion assembly 110, the top plate assembly 120, and the bottom assembly 130 can be assembled and tested separately, with various components and / or payloads integrated therewith. That is, the propulsion assembly 110 can be assembled and tested separately from the top plate assembly 120 and the bottom plate assembly 130, and vice versa. For example, this modular design opens up more possibilities for additional hosted payloads to be bolted onto the top plate assembly and then integrated into the spacecraft very late in the production flow.

[0126] (0053) Figure 3 illustrates a perspective view of an alternative embodiment of a modular spacecraft system. Some of the components of modular spacecraft system 300 are identical to those illustrated in Figures 1 and 3, although certain aspects of propulsion assembly 310, top plate assembly 320, and bottom plate assembly 330 may be modified relative to their equivalents in modular spacecraft system 100. For example, top plate assembly 310 may include a slightly modified shape of surface 342 or opening 344 compared to surface 142 and opening 144 of Figures 1 and 2, modular spacecraft system 300 may include modified brackets 350 that attach to legs 152, and bottom plate assembly 330 may include a different configuration of bolt holes and other features, thus illustrating the flexibility of modular spacecraft system 300 to accommodate various attachments thereto. Additionally, propulsion assembly 310 includes a modified frame 356 that includes a modified arrangement of openings 358. Openings 358 are configured to provide sufficient structural integrity to support propulsion system 154 while having a reduced weight compared to frame 156 of Figures 1 and 2. Various configurations of frame thickness, width, and opening shapes are contemplated and considered part of this disclosure.

[0127] (0054) FIG. 4 illustrates an exploded view 300′ of the modular spacecraft system of FIG. 3 , according to an embodiment. Similar to the embodiment illustrated in FIG. 2 , the exploded view of modular spacecraft system 300 shows various openings, bolt holes, and other features that enable separate assembly and testing of propulsion assembly 310, top plate assembly 320, and bottom plate assembly, each with its own set of attached components and payloads. Then, once the necessary testing and certification of the separate assemblies is completed, the assemblies may be bolted together to form the entire modular spacecraft system. Furthermore, if a problem arises with any component of the modular spacecraft, that particular component may be inspected separately, and / or the assembly associated with that particular component may be separated from the modular spacecraft system, repaired, recertified, and then reinstalled without affecting the other assemblies of the modular spacecraft system.

[0128] (0055) Figure 5 illustrates a portion of a process for manufacturing a modular spacecraft system, according to an embodiment. As shown in Figure 5, process 500 begins at start step 501 and then proceeds to step 510, where a propulsion assembly (e.g., propulsion assembly 110 of Figure 1 or propulsion assembly 310 of Figure 3) is assembled. The propulsion assembly so assembled is tested for space compatibility in step 512, and a determination is made in decision 514 whether the propulsion assembly is in fact space compatible. If the determination from decision 514 is "no," process 500 proceeds to step 516, where any issues with the propulsion assembly that render the assembly not space compatible are addressed. Process 500 then returns to step 512, where the propulsion assembly is again tested.

[0129] (0056) In parallel or sequentially, process 500 also includes step 520, which assembles a top plate assembly (e.g., top plate assembly 120 of FIG. 1 or top plate assembly 320 of FIG. 3). The so-assembled top plate assembly is tested for space compatibility in step 522, and a determination is made in decision 524 whether the top plate assembly is in fact space compatible. If the determination from decision 524 is "no," process 500 proceeds to step 526, which addresses any issues with the top plate assembly and attempts to bring the top plate assembly into compliance with space compatibility requirements. Process 500 then returns to step 522, where the top plate assembly is again tested.

[0130] (0057) Similarly, either in parallel or sequentially, process 500 includes step 530, which assembles a bottom plate assembly (e.g., bottom plate assembly 130 of FIG. 1 or bottom plate assembly 330 of FIG. 3). The so-assembled bottom plate assembly is tested for space compatibility in step 532, and a determination is made in decision 534 whether the bottom plate assembly is in fact space compatible. If the determination from decision 534 is "no," process 500 proceeds to step 536, where any issues with the bottom plate assembly that render the assembly not space compatible are addressed. Process 500 then returns to step 532, where the bottom plate assembly is again tested.

[0131] (0058) If the determinations from decisions 514, 524, and 534 are all "yes," process 500 proceeds to step 550 to assemble the modular spacecraft system. Process 500 proceeds to additional steps illustrated in FIG.

[0132] (0059) 6 illustrates a continuation of the steps of a process for manufacturing a modular spacecraft system, according to an embodiment. Process 500 continues with decision 610, which determines whether the so-assembled modular spacecraft system is space-qualified as an assembled system in step 550. If decision 610 determines that the assembled modular spacecraft system is, in fact, space-qualified, process 500 is terminated in final step 612.

[0133] (0060) If decision 610 determines that the assembled modular spacecraft system is not space-qualified, one or more specific assemblies (e.g., one or more of the propulsion assemblies, the top plate assembly, and the bottom plate assembly) that have issues that deviate from space-qualification are identified. The identified specific assemblies are isolated in step 622. Isolation step 622 may include, for example, partial disassembly of the assembled modular spacecraft system to disengage the specific assemblies from other assemblies that do not have the issues. In step 624, any issues with the specific assemblies are addressed, and then the specific assemblies are tested again in decision 630. If issues with the specific assemblies persist, process 500 returns to step 624 to address the identified issues in repeated attempts.

[0134] (0061) If a determination is made in decision 630 that a particular assembly is now space-qualified, the modular spacecraft system is reassembled in step 632, and process 500 returns to decision 610 to again determine whether the assembled modular spacecraft system is now space-qualified. Note that in process 500 of FIGS. 5 and 6, only the particular assembly identified as having a problem is removed, repaired, and retested. That is, unaffected assemblies do not need to be disassembled. This feature is particularly useful in manufacturing systems as complex as modular spacecraft systems. For example, unlike existing spacecraft manufacturing techniques, it is much easier to replace or repair portions of a given assembly (e.g., a top plate assembly, a propulsion assembly, and / or a bottom plate assembly) using the process embodiments described herein.

[0135] (0062) Various modifications and variations of the above-described embodiments may be contemplated, and such modifications and variations are considered part of this disclosure. Therefore, the descriptions contained herein are not intended to be limiting. Some contemplated modifications include, but are not limited to, the following:

[0136] (0063) 1. While the spacecraft bus system illustrated in Figure 1 is shown as having cubic dimensions, the dimensions of the system may be modified to be more rectangular, cylindrical, pyramidal, tetrahedral, polygonal, and other shapes, for example, to accommodate different types of propellants, improve structural rigidity, and / or allow for hosted payloads of varying shapes and sizes. The system may also be scaled to be compatible with larger or smaller payloads and propulsion systems.

[0137] (0064) 2. The components of different assemblies may include one or more cutouts and openings to improve their rigidity, reduce their weight, accommodate the attachment of additional components and payloads of various shapes and sizes, and aid in the transport and manipulation of the assemblies during the construction process.

[0138] (0065) 3. While the advantages of an all-aluminum modular spacecraft system are recognized herein, materials other than aluminum may be used for portions of the bus structure to reduce the overall system weight and / or provide improved rigidity.

[0139] (0066) 4. Additional features such as bosses, edge curvatures, leg ends, hooks, and interlocking mechanisms may be provided on the propulsion assembly, top plate assembly, or bottom plate assembly to allow stacking of the system onto the launch vehicle.

[0140] (0067) 5. One or more components of an assembly in a spacecraft bus system may be formed, for example, by additive manufacturing methods with propulsion lines embedded within the structure of the various components. For example, one or more components may be printed 3D aluminum or composite with propulsion lines embedded therein.

[0141] (0068) 6. One or more components of an assembly within a spacecraft bus system may be configured as a foldable structure. For example, a propulsion assembly may include flexible propulsion walls and containment / release mechanisms to allow the propulsion walls to fold or unfold, allowing the propulsion structure to function as a high-pressure propulsion assembly in some situations (e.g., on the ground) and a low-pressure propulsion assembly in other situations (e.g., in orbit). Such a flexible arrangement may allow more vehicles to be launched for a given volume.

[0142] (0069) 7. The propulsion assembly may be configured to support a variety of propulsion systems, including monopropellant propulsion, bipropellant propulsion, and electric propulsion.

[0143] (0070) As used herein, the recitation of "at least one of A, B, and C" is intended to mean "any of A, B, C, or any combination of A, B, and C." The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments without departing from the spirit or scope of the present disclosure. Thus, the present disclosure is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0144] (0071) The terms and expressions employed herein are used as terms and expressions of description, not of limitation, and the use of such terms and expressions is not intended to exclude any equivalents of the shown and described features or portions thereof. Each of the various elements disclosed herein can be achieved in various ways. It should be understood that the present disclosure encompasses each such variation, variations of one embodiment of any apparatus embodiment, method, or process embodiment, or even simply variations of any of these elements. In particular, it should be understood that the words for each element may be expressed by equivalent apparatus or method terms, even if only the function or result is the same. Such equivalent, broader, or even more general terms should be considered to be encompassed in the description of each element or operation. Such terms can be substituted where desired to make explicit the implicitly broad scope to which the present invention is entitled.

[0145] (0072) By way of example only, it should be understood that any action can be expressed as a means for taking that action or as an element that causes that action. Similarly, each physical element disclosed should be understood to encompass a disclosure of the action that the physical element facilitates. With regard to this last aspect, by way of example only, a disclosure of a "protrusion" should be understood to encompass a disclosure of the "protruding" action, whether or not explicitly discussed, and conversely, if there is only a disclosure of the "protruding" action, such disclosure should be understood to encompass a disclosure of the "protruding" action. Such variations and alternative terms are to be understood as expressly included within the description.

Claims

1. A spacecraft bus system, the spacecraft bus system comprising: a propulsion assembly; a top plate assembly; Bottom Plate Assembly and Equipped with The spacecraft bus system, wherein each of the propulsion assembly, the top plate assembly, and the bottom plate assembly is configured to be separately assembled and tested for space environment compatibility.

2. 10. The spacecraft bus system of claim 1, wherein each of said propulsion assembly, said top plate assembly, and said bottom plate assembly is formed from a single material.

3. 3. The spacecraft bus system of claim 2, wherein said single material is aluminum.

4. 10. The spacecraft bus system of claim 1, wherein each of the propulsion assemblies, the top plate assembly, and the bottom plate assembly is further configured to support at least one component thereon, the at least one component comprising a propellant tank, a fuel tank, a thruster, a sensor, an imager, a camera, a robotic arm, a boom arm, navigation equipment, a solar panel, an antenna, a bracket, and a mounting bracket.

5. 1. A propulsion assembly for use in conjunction with a modular spacecraft system, the propulsion assembly comprising: a propellant tank containing a propellant therein; at least one thruster; a frame configured to support the propellant tank and the at least one thruster thereon; and Equipped with The propulsion assembly is configured to be assembled as individual modules and subjected to tests related to space environment compatibility.

6. 6. The propulsion assembly of claim 5, wherein the frame is further configured for attachment to the propulsion assembly or other components of the modular spacecraft system after assembly and testing without modification to the other components of the modular spacecraft system.

7. The propulsion assembly of claim 6 , wherein the other components include a top plate assembly and a bottom plate assembly.

8. 8. The propulsion assembly of claim 7, wherein the other components further include at least one of a sensor, an imager, a camera, a robotic arm, a boom arm, navigation equipment, a solar panel, an antenna, a bracket, and a mounting bracket.

9. 1. A method for manufacturing a modular spacecraft system, the method comprising: assembling a propulsion assembly; testing the propulsion assembly for space environment compatibility; assembling a top plate assembly; independently testing the top plate assembly for space environment suitability; Assembling a bottom plate assembly; independently testing the bottom plate assembly for space environment suitability; integrating the propulsion assembly, the top plate assembly, and the bottom plate assembly to form the modular spacecraft system; A method comprising:

10. 10. The method of claim 9, further comprising testing the modular spacecraft system so formed for space environment suitability.

11. if during the testing of the modular spacecraft system so formed, a problem is found with one of the propulsion assembly, the top plate assembly, and the bottom plate assembly; identifying a particular one of the propulsion assembly, the top plate assembly, and the bottom plate assembly having the problem; addressing the problem with the particular one of the propulsion assembly, the top plate assembly, and the bottom plate assembly; retesting the particular one of the propulsion assembly, the top plate assembly, and the bottom plate assembly for space environment suitability; reintegrating the propulsion assemblies, the top plate assemblies, and the bottom plate assemblies to re-form the modular spacecraft system without retesting all of the propulsion assemblies, the top plate assemblies, and the bottom plate assemblies other than the particular one of the propulsion assemblies, the top plate assemblies, and the bottom plate assemblies to form the modular spacecraft system; 10. The method of claim 9, further comprising:

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