Connecting device and application thereof in rocket launching test equipment
The connection device, consisting of a connecting plate, a connecting base, and an adjustable connecting rod, solves the connection problem between the rocket and the test stand on a large-area high-altitude operating platform, achieving a stable, reliable, and economical connection solution.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- BEIJING DEEP BLUE AEROSPACE TECH CO LTD
- Filing Date
- 2026-01-16
- Publication Date
- 2026-05-08
AI Technical Summary
In existing technologies, the connection between the rocket and the test stand requires large-scale operations at high altitudes, which is difficult, unstable, and costly, and is prone to breakage, especially under lateral forces.
A connecting device is provided, including a connecting plate, a connecting base, a connecting assembly, and an adjustable-length connecting rod. The device achieves a stable connection between the rocket body and the test stand through the through hole and the connecting assembly, and provides tensile force using the lateral connecting rod, simplifying the operation process and improving stability.
It reduced the construction cost of the high-altitude operation platform, simplified the connection process, improved the connection stability and reliability between the rocket body and the test stand, and prevented the connecting rod from breaking under torsional force.
Smart Images
Figure CN121994492A_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of aerospace equipment technology, and in particular relates to a connecting device and its application in rocket launch test equipment. Background Technology
[0002] Rocket engine power testing is an important part of engine development. The test is conducted on a specially constructed test stand. Specifically, the rocket body with the engine installed is mounted on the test stand, and the engine components complete the required work according to a predetermined procedure. Its main purpose is to verify the feasibility of the engine design, the reliability of the process, and the methods of testing, inspection and debugging.
[0003] During rocket engine power testing, the rocket body needs to be connected to the test stand. In existing technologies, to meet the testing requirements, the connection between the rocket and the test stand needs to be carried out at a height of about 20 meters. This requires the construction of a sufficiently large operating platform at high altitude, which is difficult and costly. Alternatively, the rocket body can be connected to the test stand at the bottom via a base or adapter flange. However, the connection stability is poor when the rocket body is subjected to lateral forces during testing. Another option is to use tie rods for lateral connection of the rocket body. The connection length is fixed, the connection position of the rocket body is difficult to adjust, the operation is difficult, and the tie rods are not strong enough to break under torsional forces.
[0004] Therefore, developing a connection device and its application in rocket launch testing equipment to solve the technical defect in the existing technology that the connection between the test stand and the rocket body requires operation on a large-area operating platform at high altitude has become an urgent problem for those skilled in the art. Summary of the Invention
[0005] Therefore, it is necessary to address the technical shortcomings of existing technologies where the connection between the test stand and the rocket body requires operation on a large-area operating platform at high altitude, and to provide a connection device and its application in rocket launch test equipment.
[0006] This application provides a connection device between a rocket body and a test stand. The connection device includes a connecting plate, a connecting base, a connecting assembly, and a connecting rod. The upper surface of the connecting plate contacts the bottom surface of the rocket body and is fixed by the connecting assembly. The lower surface of the connecting base contacts the upper surface of the test stand and is fixed by the connecting assembly. The outer edge of the connecting plate has a plurality of first through holes, and the outer edge of the connecting base has a plurality of second through holes. The first through holes and the second through holes correspond one-to-one. The connecting assembly passes through the first through holes and the second through holes to connect the lower surface of the connecting plate to the upper surface of the connecting base. The two ends of the connecting rod are respectively connected to the side of the rocket body and the upper surface of the test stand or the connecting base.
[0007] In one embodiment, the number of the first through holes is n, and the radius of the first through holes is r. The formula for calculating the number n of the first through holes is: ; Wherein, Tsj is the total thrust load of the engine of the rocket body; This represents the allowable stress of the connecting screw.
[0008] In one embodiment, the angle between the connecting rod and the arrow body is θ. The formula for calculating the angle θ between the connecting rod and the arrow body is: ; Wherein, Ts is the lateral load generated by the rocket body when the engine swings to its maximum angle; f is the safety factor of the arrow body; F is the maximum tensile force that the connecting rod can withstand.
[0009] In one embodiment, the connecting plate is provided with a plurality of third through holes, each of which corresponds one-to-one with a mounting hole on the bottom surface of the arrow body. The connecting assembly passes through the third through holes and is fixedly connected to the connecting plate and the arrow body through the mounting holes on the bottom surface of the arrow body.
[0010] In one embodiment, the connecting base is provided with a plurality of fourth through holes, each of which corresponds one-to-one with the mounting holes on the upper surface of the test bench. The connecting component passes through the fourth through holes and is fixedly connected to the connecting base and the test bench by the mounting holes on the upper surface of the test bench.
[0011] In one embodiment, the connecting rod is an adjustable length connecting rod.
[0012] In one embodiment, the connecting rod includes: a first connector, a threaded rod, and a second connector. The two ends of the threaded rod are respectively connected to the first connector and the second connector. The inner walls of the first connector and the second connector are respectively provided with threads that match the threads at both ends of the threaded rod. The threaded rod rotates relative to the first connector and the second connector to adjust the length of the connecting rod. The other end of the first connector is connected to the arrow body, and the other end of the second connector is connected to the test stand or the connecting base.
[0013] In one embodiment, the connecting rod further includes a hook disposed between the second connector and the test bench or connecting base.
[0014] This application also provides the application of any of the above-described connecting devices in rocket launch test equipment.
[0015] In summary, this application provides a connection device between a rocket body and a test stand, comprising: a connecting plate, a connecting base, a connecting assembly, and a connecting rod. The upper surface of the connecting plate contacts the bottom surface of the rocket body and is fixed by the connecting assembly. The lower surface of the connecting base contacts the upper surface of the test stand and is fixed by the connecting assembly. The outer edge of the connecting plate has a plurality of first through holes, and the outer edge of the connecting base has a plurality of second through holes, with each of the first and second through holes corresponding one-to-one. The connecting assembly passes through the first and second through holes to connect the lower surface of the connecting plate to the upper surface of the connecting base. The two ends of the connecting rod are respectively connected to the side of the rocket body and the upper surface of the test stand or the connecting base. This application also provides the application of the above-mentioned connection device in rocket launch test equipment. In the technical solution provided in this application, the rocket body and the test stand are connected by a connecting plate and a connecting base respectively, and then the connecting plate and the connecting base are fixed, making the connection more convenient and quick, without requiring a large operating space; at the same time, the connecting rod can provide lateral tension, further improving the connection stability between the rocket body and the test stand; it solves the technical defect in the prior art that the connection between the test stand and the rocket body requires operation on a large operating platform at high altitude. Attached Figure Description
[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.
[0017] Figure 1 A cross-sectional structural diagram of the connection surface between the connecting device and the rocket body and the test stand in the technical solution provided in the embodiments of this application; Figure 2 A side view of the connection surface between the connecting device and the rocket body and the test stand in the technical solution provided in the embodiments of this application; Figure 3 A schematic diagram of the structure of a connecting plate in a connecting device provided in an embodiment of this application; Figure 4 A schematic diagram of the structure of the connecting base in a connecting device provided in an embodiment of this application; The components include a connecting plate 1, a first through hole 11, a third through hole 12, a connecting base 2, a second through hole 21, a fourth through hole 22, a connecting rod 3, a first connector 31, a threaded rod 32, a second connector 33, a hook 34, a connecting assembly 4, an arrow body 5, and a test stand 6. Detailed Implementation
[0018] This application provides a connecting device and its application in rocket launch test equipment, which solves the technical defect in the prior art that the connection between the test stand and the rocket body needs to be operated on a large-area operating platform at high altitude.
[0019] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.
[0020] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.
[0021] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.
[0022] In this application, unless otherwise expressly specified and limited, the terms "installation," "contact and fixation through the connecting component," "connection," and "fixation," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to direct contact and fixation through the connecting component, or indirect contact and fixation through the connecting component via an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.
[0023] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.
[0024] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.
[0025] Please see Figures 1 to 4 This application provides a connection device between a rocket body 5 and a test stand 6, comprising: a connecting plate 1, a connecting base 2, a connecting assembly 4, and a connecting rod 3. The upper surface of the connecting plate 1 contacts the bottom surface of the rocket body 5 and is fixed by the connecting assembly. The lower surface of the connecting base 2 contacts the upper surface of the test stand 6 and is fixed by the connecting assembly. The outer edge of the connecting plate 1 is provided with a plurality of first through holes 11, and the outer edge of the connecting base 2 is provided with a plurality of second through holes 21. The first through holes 11 and the second through holes 21 correspond one-to-one. The connecting assembly 4 passes through the first through holes 11 and the second through holes 21 to connect the lower surface of the connecting plate 1 and the upper surface of the connecting base 2. The two ends of the connecting rod 3 are respectively connected to the side of the rocket body 5 and the test stand 6 or the upper surface of the connecting base 2.
[0026] Figure 3 The diagram shows the structure of the connecting plate 1. The connecting plate 1 has an opening in the center, which matches the bottom of the rocket body 5. This ensures that the upper surface of the connecting plate 1 is fixedly connected to the bottom of the rocket body 5 and does not affect the test run of the rocket body 5. Figure 4 The diagram shows the structure of the connecting base 2. The connecting base 2 has an opening in the center, which matches the test bench 6. This ensures that after the lower surface of the connecting base 2 is fixedly connected to the upper part of the test bench 6, it will not affect the test of the test bench 6.
[0027] The lower surface of the connecting plate 1 is connected and fixed to the upper surface of the connecting base 2. The connecting plate 1 is connected to the connecting base 2 via the first through hole 11 on its outer edge and the second through hole 21 on its outer edge by the connecting assembly 4, thus fixing the rocket body 5 to the test stand 6 in the vertical direction. At the same time, one end of the lateral connecting rod 3 is fixed to the rocket body 5, and the other end of the connecting rod 3 is connected and fixed to the test stand 6 or the upper surface of the connecting base 2, providing lateral tensile force to fix the connection structure between the rocket body 5 and the test stand 6.
[0028] In the connecting device provided in this embodiment, the connecting plate 1 and the connecting base 2 are designed to be compact and can be tailored to the specific structures of the rocket body 5 and the test stand 6. The rocket body 5 and the test stand 6 can be stably connected to the connecting plate 1 and the connecting base 2, respectively. Furthermore, the connecting assembly 4 connects and fixes the first through hole 11 and the second through hole 21, thereby fixing the connecting plate 1 and the connecting base 2.
[0029] Since the first through hole 11 and the second through hole 21 are in a one-to-one correspondence, when aligning the connecting plate 1 and the connecting base 2, only one of the first through holes 11 and the second through hole 21 needs to be aligned to complete the one-to-one correspondence of all the first through holes 11 and the second through holes 21, making the connection process simple and convenient. However, the connecting holes on the outer edge of the rocket body 5 are relatively irregular. Compared with the direct connection method between the rocket body 5 and the test stand 6, the technical solution provided in this application can effectively simplify the connection process between the rocket body 5 and the test stand 6. When connecting the rocket body 5 and the connecting stand, a large operating space is not required, i.e., there is no need to build a large operating platform at high altitude.
[0030] Meanwhile, both ends of the connecting rod 3 are connected to the side of the rocket body 5 and the upper surface of the test stand 6 or the connecting base 2, respectively, providing lateral support for the connection structure between the rocket body 5 and the test stand 6, further enhancing the connection stability between the rocket body 5 and the test stand 6. In practical applications, the number of connecting rods 3 can be adjusted according to actual design requirements; specifically, it can be 2, 4, or other numbers of connecting rods 3.
[0031] In practical applications, the connecting component 4 can be a screw, and the specifications of the screw can be adjusted according to the actual assembly requirements.
[0032] To further optimize the technical solution, while ensuring a stable connection between the connecting plate 1 and the connecting base 2, and taking into account the simplification of the structural design, in the technical solution provided in this application embodiment, the number of first through holes 11 is n, the radius of the first through holes 11 is r, and the formula for calculating the number of first through holes n is: Where Tsj is the total thrust load of the rocket body's engine; This represents the allowable stress of the connecting screw.
[0033] To further optimize the technical solution, in order to effectively ensure the connection stability between the connecting rod 3 and the arrow body 5, while also taking into account a smaller space occupation, the technical solution provided in this application embodiment has an angle θ between the connecting rod 3 and the arrow body 5. The formula for calculating the angle θ between the connecting rod and the arrow body is as follows: Where Ts is the lateral load generated by the rocket body when the engine swings to its maximum angle; f is the safety factor of the rocket body; and F is the maximum tensile force that the connecting rod can withstand.
[0034] To ensure sufficient lateral support strength for the connecting rod 3 while also considering the design requirements for lightweight construction, the outer diameter of the connecting rod 3 in the technical solution provided in this application embodiment is d, and the formula for calculating the outer diameter d of the connecting rod is: Where F1 is the tensile force borne by the connecting rod; This represents the allowable stress of the connecting rod material.
[0035] To effectively enhance the connection strength between the connecting plate 1 and the arrow body 5 and facilitate their connection and fixation, in the technical solution provided in this application embodiment, the connecting plate 1 is provided with a plurality of third through holes 12, and the third through holes 12 correspond one-to-one with the mounting holes on the bottom surface of the arrow body 5. The connecting component 4 passes through the third through holes 12 and is fixedly connected to the connecting plate 1 and the arrow body 5 by the mounting holes on the bottom surface of the arrow body 5.
[0036] Similarly, in order to effectively enhance the connection strength between the connecting base 2 and the test bench 6 and facilitate their connection and fixation, the connecting device provided in this application embodiment has a plurality of fourth through holes 22. The fourth through holes 22 correspond one-to-one with the mounting holes on the upper surface of the test bench 6. The connecting component 4 passes through the fourth through holes 22 and is fixedly connected to the connecting base 2 and the test bench 6 with the mounting holes on the upper surface of the test bench 6.
[0037] To further optimize the technical solution, in the technical solution provided in this application embodiment, the connecting rod 3 is an adjustable length connecting rod 3. The length of the connecting rod 3 can be adjusted according to different actual connection positions, effectively reducing the operational difficulty of connecting the connecting rod 3.
[0038] In a connecting device provided in this application embodiment, the connecting rod 3 includes: a first connector 31, a threaded rod 32, and a second connector 33. The two ends of the threaded rod 32 are respectively connected to the first connector 31 and the second connector 33. The inner walls of the first connector 31 and the second connector 33 are respectively provided with threads, which match the threads at both ends of the threaded rod 32. The threaded rod 32 rotates relative to the first connector 31 and the second connector 33 to adjust the length of the connecting rod 3. The other end of the first connector 31 is connected to the arrow body 5, and the other end of the second connector 33 is connected to the test bench 6 or the connecting base 2. When adjusting the length of the connecting rod 3, only the middle threaded rod 32 needs to be rotated, making length adjustment convenient and quick.
[0039] To further optimize the technical solution, in the technical solution provided in this application embodiment, to prevent the connection between the second joint 33 and the test bench 6 or the connecting base 2 from breaking due to insufficient strength when subjected to torsional force during the rotation of the threaded rod 32, the connecting rod 3 further includes a hook 34, which is disposed between the second joint 33 and the test bench 6 or the connecting base 2. The hook 34 can rotate accordingly when the threaded rod 32 rotates, enhancing the stability of the connecting rod 3 and the test bench 6 or the connecting base 2.
[0040] From the above technical solutions, it can be concluded that the connecting device provided in the embodiments of this application has the following advantages: 1. Compared with the prior art, which requires the construction of a large operating platform at high altitude to connect the rocket body and the test stand, the construction cost of the test platform in the prior art is relatively high. In this application, the rocket body and the test stand are connected by contact between the connecting plate and the connecting base and by fixing the connecting components. A simple mechanical connection method is adopted, which makes the connection process simple and easy to operate, and reduces the cost of building a test operation platform. 2. In the prior art, the rocket body is only connected at the bottom during the test run, resulting in poor stability when the rocket body is subjected to lateral forces. In this application, a lateral connecting rod is used to provide lateral tension for connection, ensuring the stability and reliability of the rocket body during the test run. 3. In the prior art, the connection position requirements are high when the test stand is connected to the rocket body laterally, and the operation is difficult. In this application, the length of the connecting rod is adjustable, the connection position requirements are not high, which greatly reduces the operation difficulty during connection and makes it easier to operate; and the rod will not break due to insufficient strength when subjected to torsional force.
[0041] Based on this, the present application provides a connection device for a rocket body and a test stand, which connects the bottom of the rocket body to the test stand via a connecting plate and a connecting base. This simple mechanical connection is further enhanced by an adjustable lateral connecting rod. Tightening and loosening are achieved simply by turning the central screw, making the connection simple, quick, and highly practical. Furthermore, the connection between the rocket body and the test stand via the connecting plate and connecting base reduces the cost of constructing a test operation platform. The lateral connection via the adjustable lateral connecting rod, which is not easily broken under torsional forces, lowers the requirements for the rocket body connection position, facilitating operation and effectively saving costs associated with high-precision positioning. Simultaneously, testing shows that the connection between the rocket body and the test stand provided in this application has high stability and reliability. The connection device for a rocket body and a test stand provided in this application has the advantages of strong practicality, low cost, and high reliability, and can be applied to rocket launch testing equipment.
[0042] In summary, this application provides a connection device between a rocket body and a test stand, comprising: a connecting plate, a connecting base, a connecting assembly, and a connecting rod. The upper surface of the connecting plate contacts the bottom surface of the rocket body and is fixed by the connecting assembly. The lower surface of the connecting base contacts the upper surface of the test stand and is fixed by the connecting assembly. The outer edge of the connecting plate has a plurality of first through holes, and the outer edge of the connecting base has a plurality of second through holes, with each of the first and second through holes corresponding one-to-one. The connecting assembly passes through the first and second through holes to connect the lower surface of the connecting plate to the upper surface of the connecting base. The two ends of the connecting rod are respectively connected to the side of the rocket body and the upper surface of the test stand or the connecting base. This application also provides the application of the above-mentioned connection device in rocket launch test equipment. In the technical solution provided in this application, the rocket body and the test stand are connected by a connecting plate and a connecting base respectively, and then the connecting plate and the connecting base are fixed, making the connection more convenient and quick, without requiring a large operating space; at the same time, the connecting rod can provide lateral tension, further improving the connection stability between the rocket body and the test stand; it solves the technical defect in the prior art that the connection between the test stand and the rocket body requires operation on a large operating platform at high altitude.
[0043] The technical features of the embodiments described above can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification. Furthermore, other implementation methods can be derived from the above embodiments, allowing for structural and logical substitutions and changes without departing from the scope of this disclosure.
[0044] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.
Claims
1. A connection device between an arrow body and a test stand, characterized in that, The connecting device includes a connecting plate, a connecting base, a connecting assembly, and a connecting rod. The upper surface of the connecting plate contacts the bottom surface of the rocket body and is fixed by the connecting assembly. The lower surface of the connecting base contacts the upper surface of the test stand and is fixed by the connecting assembly. The outer edge of the connecting plate has a plurality of first through holes, and the outer edge of the connecting base has a plurality of second through holes. The first through holes and the second through holes correspond one-to-one. The connecting assembly passes through the first through holes and the second through holes to fix the lower surface of the connecting plate to the upper surface of the connecting base. The two ends of the connecting rod are respectively connected to the side of the rocket body and the upper surface of the test stand or the connecting base.
2. The connecting device according to claim 1, characterized in that, The number of the first through holes is n, and the radius of the first through holes is r. The formula for calculating the number n of the first through holes is: ; Wherein, Tsj is the total thrust load of the engine of the rocket body; This represents the allowable stress of the connecting screw.
3. The connecting device according to claim 1 or 2, characterized in that, The angle between the connecting rod and the arrow body is θ. The formula for calculating the angle θ between the connecting rod and the arrow body is: ; Wherein, Ts is the lateral load generated by the rocket body when the engine swings to its maximum angle; f is the safety factor of the arrow body; F is the maximum tensile force that the connecting rod can withstand.
4. The connecting device according to claim 3, characterized in that, The outer diameter of the connecting rod is d. The formula for calculating the outer diameter d of the connecting rod is: ; Wherein, F1 is the tensile force borne by the connecting rod; The allowable stress of the connecting rod material is given.
5. The connecting device according to claim 1, characterized in that, The connecting plate is provided with a plurality of third through holes, each of which corresponds one-to-one with the mounting holes on the bottom surface of the arrow body. The connecting assembly passes through the third through holes and is fixedly connected to the connecting plate and the arrow body by the mounting holes on the bottom surface of the arrow body.
6. The connecting device according to claim 1, characterized in that, The connecting base is provided with a plurality of fourth through holes, each of which corresponds one-to-one with the mounting holes on the upper surface of the test bench. The connecting component passes through the fourth through holes and is fixedly connected to the connecting base and the test bench by the mounting holes on the upper surface of the test bench.
7. The connecting device according to any one of claims 1 to 4, characterized in that, The connecting rod is an adjustable length connecting rod.
8. The connecting device according to claim 7, characterized in that, The connecting rod includes a first connector, a threaded rod, and a second connector. The two ends of the threaded rod are connected to the first connector and the second connector, respectively. The inner walls of the first connector and the second connector are respectively provided with threads that match the threads at both ends of the threaded rod. The threaded rod rotates relative to the first connector and the second connector to adjust the length of the connecting rod. The other end of the first connector is connected to the arrow body, and the other end of the second connector is connected to the test stand or the connecting base.
9. The connecting device according to claim 8, characterized in that, The connecting rod further includes a hook, which is disposed between the second connector and the test bench or connecting base.
10. The application of the connecting device according to any one of claims 1 to 9 in a rocket launch test equipment.