Gas circuit polarity test method of Hall electric propulsion system on satellite

Abstract

The invention provides a method for testing the gas circuit polarity of a Hall electric propulsion system on a satellite, which comprises the following steps of: closing a gas circuit valve of the Hall electric propulsion system, filling helium into a pipeline and an upstream buffer gas cylinder, disconnecting all electric connectors of flow control modules of the Hall electric propulsion system, and only keeping the connection of the electric connectors of the flow control modules to be verified; sealing anode and cathode outlets of the to-be-tested thruster, electrifying the whole satellite, and opening a flow control module valve corresponding to the to-be-tested thruster, so that one cathode and anode outlet supplies gas, and other cathode outlets do not supply gas; then, measuring the helium concentration at the outlets of the cathode and the anode by using a helium mass spectrometer probe, and verifying the gas circuit polarities of the cathode and the anode; switching a to-be-tested thruster valve, and repeating the steps to verify the polarity of all cathode outlet gas paths; and finally, sequentially switching to other thrusters, and repeating the operation to complete the polarity verification of all thrusters. Therefore, the problem that the Hall electric propulsion system cannot perform gas circuit polarity detection after satellite assembly is solved, so that the reliability and robustness of the electric propulsion system are improved.

Description

Technical Field

[0001] The present invention relates to the field of spacecraft testing, and particularly to a method for testing the gas path polarity of a Hall electric propulsion system on a satellite. Background Art

[0002] Compared with traditional chemical propulsion, space electric propulsion technology has the inherent advantage of high specific impulse, which means that to complete the same flight propulsion mission, using electric propulsion can carry less propellant, so that the satellite can be equipped with more payloads. Therefore, electric propulsion technology has gradually become the standard configuration of satellite propulsion systems. Among them, the Hall electric propulsion technology is the most mature and widely used in design. For example, the SPT Hall electric propulsion technology of Russia has a total of about 500 units in orbit. According to different missions and satellite types, a Hall electric propulsion system with a Hall thruster as the core usually configures one or four Hall thrusters. The electric propulsion configured for low-earth orbit satellites weighing in the order of hundreds of kilograms is generally used for orbit raising or orbit maintenance, so usually one Hall thruster is configured; the electric propulsion configured for geostationary orbit satellite platforms weighing in the order of thousands of kilograms is generally used for orbit transfer or phase keeping, usually four Hall thrusters are configured. And because the satellite body is large, the electric propulsion pipeline cannot be delivered as a whole. After the pipeline is installed on the satellite, it is welded in sections, and there is a risk that the pipeline connection polarity is incorrect.

[0003] The working principle of a Hall thruster requires ionizing a gaseous propellant (usually xenon), and then using a high-voltage potential drop to accelerate the ionized ions to form a thrust. Therefore, a Hall electric propulsion system needs to be specially equipped with a power supply system and a gas supply system. In addition, due to the high cost, complex structure and numerous interfaces between systems of geostationary orbit satellites, it is difficult to ensure correctness only by process control. Therefore, various single machines must be tested and verified internally and between systems after being installed on the satellite, so as to ensure the interface matching, electrical interface, gas path interface and the correctness of installation on the satellite through tests. For a Hall electric propulsion system, the best way to verify is to conduct a real ignition test on the Hall thruster.

[0004] However, due to the particularity of the Hall thruster, its real ignition test must be carried out in a vacuum. Ignition under atmospheric conditions will cause fatal damage to the thruster. During the overall assembly and testing of the satellite, only the overall satellite thermal vacuum test has a vacuum condition. However, all optical sensors have been installed on the satellite during the overall satellite thermal vacuum test. At this time, when the Hall thruster is ignited, its high-energy plasma beam will be deposited on the surface of the optical sensors, thereby causing irreversible damage to the device surface (such as OSR sheets, solar wing battery sheets, star sensors, optical lenses, etc.). Therefore, the Hall electric propulsion system does not have the conditions for ignition verification after being assembled into the whole satellite. That is to say, the Hall electric propulsion system after being installed on the satellite cannot conduct a comprehensive system verification, and the reliability and robustness of the system are difficult to guarantee.

[0005] For the power supply path of the Hall electric propulsion system, the Hall thruster can be effectively verified by using a simulated load to replace the Hall thruster. The simulated load can equivalently represent the plasma impedance in the anode and cathode assemblies inside the thruster during actual ignition, enabling the Hall power processing unit to output at the rated power. The correctness of the cable / plug connection polarity in the electrical path of the system can be verified by monitoring the telemetry of the power processing unit.

[0006] However, since the Hall thruster cannot be actually ignited, it creates a dilemma where the gas path polarity of the system cannot be verified. Since the electric propulsion gas flow rate is on the order of mg / s, the external pressure induction method used in conventional chemical propulsion is difficult to implement. Currently, the process assurance method is usually adopted, that is, strictly following the general assembly process during the welding process of the electric propulsion pipeline on the satellite, but it cannot be verified and proven. In addition, there is also a method of testing and proving by collecting gas with an airbag, but this method is likely to introduce foreign objects into the pipeline interior, and the outlet structure of the Hall thruster is irregular, making it difficult to seal the airbag. Therefore, this method can only verify some pipelines.

[0007] Therefore, there is an urgent need for an effective method to test the gas path polarity of the Hall electric propulsion. Summary of the Invention

[0008] The purpose of the present invention is to provide a method for testing the gas path polarity of a Hall electric propulsion system on a satellite, aiming to solve the problem that the gas path polarity cannot be detected after the general assembly of the Hall electric propulsion system on the satellite, and improve the reliability and robustness of the electric propulsion system.

[0009] To achieve the above purpose, the present invention provides a method for testing the gas path polarity of a Hall electric propulsion system on a satellite, including the following steps:

[0010] (1) Control the gas path valve of the Hall electric propulsion system to be in a closed state, fill helium gas with a pressure higher than the ambient pressure into the pipeline interior, and fill high-pressure helium gas into the upstream buffer gas cylinder.

[0011] (2) Disconnect the electrical connectors of all flow control modules of the Hall electric thrusters on the entire satellite, and only retain the connection of the electrical connector of the flow control module to be verified.

[0012] (3) Seal the anode outlet and each cathode outlet of the thruster to be tested.

[0013] (4) Power on the entire satellite and open the valve of the flow control module corresponding to the thruster to be tested to ensure that one of the cathode outlets and the anode outlet are supplied with gas, and the other cathode outlets are not supplied with gas.

[0014] (5) Use a helium mass spectrometer probe to penetrate the sealing material, and measure the helium concentration at the cathode outlet without gas supply and the cathode outlet with gas supply in sequence. Compare the two measurement results to verify the cathode gas path polarity;

[0015] (6) Use a helium mass spectrometer probe to penetrate the sealing material to measure the helium concentration at the anode outlet. If its concentration is higher than that at the cathode outlet, it verifies that the anode gas path polarity is correct;

[0016] (7) Switch the valve of the flow control module corresponding to the thruster to be tested, and repeat steps (4) to (5) until the gas path polarities of all cathode outlets corresponding to the thruster to be tested are verified;

[0017] (8) Switch to other thrusters in sequence and repeat steps (3) to (7) to complete the verification of the gas path polarities of all thrusters.

[0018] Optionally, in step (1), the helium pressure inside the pipeline exceeds 0.2 MPa, and the helium pressure in the upstream buffer gas cylinder exceeds 1 MPa.

[0019] Optionally, in step (3), the sealing uses a protective film and a sealing tape, and the protective film sealing method at the anode outlet is different from the sealing tape sealing method at the cathode outlet.

[0020] Optionally, in step (8), when switching to other thrusters, select other thrusters on the opposite side of the star from the thruster to be tested to avoid the influence of helium diffusion on the measurement results.

[0021] Optionally, in steps (5) and (6), if the helium concentration is close to the upper limit of the mass spectrometer measurement, split the test process into multiple times, or take the average value through multiple measurements to improve the accuracy.

[0022] Optionally, after the test, restore the connection of the electrical connectors of all flow control modules, and close the valves of the corresponding flow control modules.

[0023] Optionally, in step (5), the measurement result of the helium mass spectrometer probe takes the helium concentration at the cathode outlet without gas supply as the reference value, and when the helium concentration at the cathode outlet with gas supply is higher than the reference value, it is determined that its gas path polarity is correct.

[0024] The method for testing the gas path polarity of the Hall electric propulsion system on a satellite according to the present invention realizes the detection of the gas path polarity of the Hall electric propulsion system after the overall assembly of the satellite through the method of detecting by a mass spectrometer and by using the measures of plugging the outlet of the thruster and turning on and off the connectors; solves the problem that the gas path polarity of the Hall electric propulsion system cannot be detected after the overall assembly of the satellite, avoids the risk of incorrect connection polarity of the electric propulsion pipeline, and thus improves the reliability and robustness of the electric propulsion system; during the testing process, the pipeline is under positive pressure from the upstream to the downstream, and all the products used are the products used on the satellite, so there is no risk of introducing foreign objects into the interior of the electric propulsion pipeline; the method provided by the present invention can realize the full gas path detection of the electric propulsion pipeline from the upstream gas cylinder to the thruster outlet. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 FIG. is a flowchart of the steps of the method for testing the gas path polarity of the Hall electric propulsion system on a satellite provided by an embodiment of the present invention;

[0026] Figure 2 FIG. is a schematic diagram of the configuration of the electric propulsion pipeline of the method for testing the gas path polarity of the Hall electric propulsion system on a satellite provided by an embodiment of the present invention;

[0027] Figure 3 FIG. is a schematic diagram of the electric propulsion pipeline in the testing step (1) of the method for testing the gas path polarity of the Hall electric propulsion system on a satellite provided by an embodiment of the present invention;

[0028] Figure 4 FIG. is a schematic diagram of the electric propulsion pipeline in the testing step (2) of the method for testing the gas path polarity of the Hall electric propulsion system on a satellite provided by an embodiment of the present invention;

[0029] Figure 5 FIG. is a schematic diagram of the electric propulsion pipeline in the testing step (3) of the method for testing the gas path polarity of the Hall electric propulsion system on a satellite provided by an embodiment of the present invention;

[0030] Figure 6 FIG. is a schematic diagram of the test state of the Hall thruster used in the method for testing the gas path polarity of the Hall electric propulsion system on a satellite provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0032] It should be noted that the references to "one embodiment", "embodiment", "example embodiment", etc. in this specification mean that the described embodiment may include specific features, structures or characteristics, but not every embodiment must include these specific features, structures or characteristics. In addition, such expressions do not refer to the same embodiment. Further, when combining specific features, structures or characteristics with an embodiment, whether or not there is an explicit description, it has been shown that it is within the knowledge of those skilled in the art to combine such features, structures or characteristics with other embodiments.

[0033] In addition, in the specification and subsequent claims, certain terms are used to refer to specific components or parts. Those of ordinary skill in the art should understand that the manufacturer may use different nouns or terms to refer to the same component or part. The specification and subsequent claims do not use the difference in name as a way to distinguish components or parts, but use the difference in function of components or parts as the criterion for distinction. The terms "comprising" and "including" mentioned throughout the specification and subsequent claims are open-ended terms, so they should be interpreted as "including but not limited to". In addition, the term "connected" herein includes any direct and indirect electrical connection means. Indirect electrical connection means include connection through other devices.

[0034] Before describing the embodiments of the present application in detail, first briefly describe the technical concept of the present application: Aiming at the problem that the prior art cannot verify the gas path polarity of the Hall electric propulsion, in order to avoid the risk of incorrect connection polarity of the electric propulsion pipeline, the present invention provides a method for testing the gas path polarity of the Hall electric propulsion system on a satellite. By first closing the gas path valve of the Hall electric propulsion system, filling helium, disconnecting the electrical connector of the flow control module, a stable and interference-free environment is created; then sealing the outlet of the thruster to be tested, powering on the whole satellite and opening the corresponding valve to supply gas to a specific outlet; then using a helium mass spectrometer probe to measure the helium concentration at different outlets to verify the cathode and anode gas path polarities; after verifying all the cathode outlets of a single thruster, switch to other thrusters and repeat the operation to complete the verification of the gas path polarities of all thrusters.

[0035] Next, the specific principle of the method for testing the gas path polarity of the Hall electric propulsion system of the present application on a satellite will be described in combination with specific embodiments.

[0036] Figure 1 Figure 1 shows a method for testing the gas path polarity of a Hall electric propulsion system on a satellite provided by an embodiment of the present invention. Usually, the Hall thruster is configured with two cathodes, that is, one anode assembly and two cathode assemblies. Therefore, this embodiment will be specifically described with the two-cathode configuration; of course, in other examples, the Hall thruster can also be other multi-cathode configurations.

[0037] The method includes the following steps:

[0038] S101: Control the gas path valve of the Hall electric propulsion system to be in the closed state, fill helium gas with a pressure higher than the ambient pressure into the pipeline, and fill high-pressure helium gas into the upstream buffer gas cylinder; before the test, it is necessary to ensure that all the valves inside the Hall electric propulsion gas path system are in the closed state, the inside of the pipeline is filled with helium gas as a protective gas with a pressure higher than the ambient pressure, and the inside of the upstream buffer gas cylinder is also filled with helium gas; in order to ensure that there is enough gas participating in the test during the test, the helium gas pressure inside the pipeline in this embodiment exceeds 0.2 MPa, and the helium gas pressure in the upstream buffer gas cylinder exceeds 1 MPa; after completing this step, the next step can be entered.

[0039] In this embodiment, taking the Hall electric propulsion system of the high-orbit satellite platform with the most complex configuration as an example, specifically taking the internationally most widely used SPT-100 Hall thruster as an example, which is applied to a high-orbit satellite with a launch weight of 4.5 tons. The satellite is equipped with four SPT-100 Hall thrusters for in-orbit north-south position keeping. Therefore, the four thrusters are respectively placed on the north and south plates of the satellite. The thrusters on the same side are mutual main and backup, and are 50 cm apart. Each SPT-100 Hall thruster is composed of an anode assembly and a cathode assembly. To improve reliability, the thruster is equipped with two cathode assemblies, which are mutual main and backup. During the operation of the thruster, the anode and one of the cathodes work. The thruster needs to be equipped with a flow control module (XFC, Xenon Flow Control). Each XFC can supply gas to the anode and one cathode at the same time. Therefore, the upstream gas supply of each thruster consists of two XFCs. The anodes of the two XFCs are connected through a tee pipeline to supply the only anode on the thruster.

[0040] See Figure 2 , this high-orbit satellite is equipped with four Hall thrusters and eight XFCs, and its gas path configuration is as shown by the connection lines between the modules in Figure 2 . For simplicity of expression, only the buffer gas cylinder is shown upstream of the XFC. This simplification does not affect the implementation steps of the present invention.

[0041] S102: Disconnect the electrical connectors of all the flow control modules of the Hall electric thrusters on the whole satellite, and only keep the electrical connectors of the flow control module to be verified connected; before the test, it is necessary to disconnect the electrical connectors of all the flow control modules (XFCs), and only keep the electrical connectors of the XFCs that need to be verified connected; the electrical connectors of the XFCs to be verified can also be re-opened in the subsequent step S104.

[0042] S103: Seal the anode outlet and each cathode outlet of the thruster to be tested; specifically, the sealing uses a protective film and a sealing tape, and the sealing method of the protective film at the anode outlet is different from the sealing method of the sealing tape at the cathode outlet.

[0043] Since the flow rate at the anode outlet is 10 times that of the cathode, a protective film was used to seal the anode outlet of the thruster before the test, and a sealing tape was used to seal the cathode outlet, as Figure 6 shown. Both the protective film and the sealing tape are commonly used products on the satellite. Since the products used are for on-satellite use, there is no risk of introducing foreign objects into the internal electric propulsion pipeline.

[0044] S104: Power on the entire satellite and open the valve of the flow control module corresponding to the thruster to be tested to ensure gas supply at one cathode outlet and the anode outlet, and no gas supply at other cathode outlets; see Figure 3 , in a specific example, power on the entire satellite and open the valve of XFC-A corresponding to the south-side main Hall thruster (if the electrical connector of XFC-A was not reserved in the previous step, first connect the electrical connector of XFC-A). After the valve of XFC-A is opened, both the cathode A and the anode outlet on the south-side main Hall thruster start to exhaust gas. At this time, it can be observed that the telemetry of the pressure in the upstream buffer gas cylinder starts to decrease, indicating that downstream exhaust has started. The upstream and downstream in this embodiment are distinguished by the location of the gas source (buffer gas cylinder), that is, the location of the gas source is upstream, and the pipeline far from the gas source is downstream.

[0045] S105: Use a helium mass spectrometer probe to penetrate the sealing material and measure the helium concentration at the non-gas-supplied cathode outlet and the gas-supplied cathode outlet in sequence, and compare the two measurement results to verify the cathode gas path polarity.

[0046] During specific implementation, see Figure 3 , after the exhaust starts, first use a helium mass spectrometer probe to penetrate the sealing tape and sniff the outlet of cathode B to measure its helium concentration, denoted as measurement value b; since only the valve of XFC-A is opened and cathode B is not supplied with gas at this time, there is no helium gas flow in the cavity of cathode B, so the measurement value b of the helium concentration inside the cavity of cathode B measured at this time is used as a reference benchmark.

[0047] After completing the measurement of cathode B, see Figure 4 , use a helium mass spectrometer probe to penetrate the sealing tape and sniff the outlet of cathode A to measure its helium concentration, which is denoted as measurement value a at this time; then compare measurement value a and measurement value b. As long as the helium concentration at the outlet of cathode A is higher than the benchmark of cathode B, that is, measurement value a is higher than measurement value b, it is considered that the gas path polarities of cathode A and B of this thruster are correct; that is, the measurement result of the helium mass spectrometer probe uses the helium concentration at the non-gas-supplied cathode outlet as the reference value, and when the helium concentration at the gas-supplied cathode outlet is higher than the reference value, it is determined that its gas path polarity is correct.

[0048] After completing the measurement of the cathode outlet, proceed to step S106 to measure the gas path polarity of the anode outlet.

[0049] Since the linear distance between the outlets of cathode A and cathode B is 3 - 5 cm, and the diffusion rate of helium is extremely fast, it may be impossible to observe the difference between the reference value and the measured value during the test. Therefore, in this embodiment, the outlets of the cathode and the anode are temporarily sealed with a protective film and a sealing tape.

[0050] S106: Use a helium mass spectrometer probe to penetrate the sealing material to measure the helium concentration at the anode outlet. If the concentration is higher than that at the cathode outlet, it is verified that the polarity of the anode gas path is correct.

[0051] During specific implementation, as Figure 5 shown, use a probe to penetrate the anode protective film and sniff the anode outlet to measure its helium concentration, denoted as the measured value c. Then compare the measured value c with the measured values a and b. If the measured value c is greater than the measured values a and b, that is, the helium concentration at the anode outlet is higher than that at the two cathode outlets, it is considered that the gas path polarities of the thruster anode and cathode are both correct. At this time, the verification of the gas path polarity of the thruster is completed. After completing the verification of the anode gas path polarity, immediately close the XFC valve.

[0052] S107: Switch the valve of the flow control module corresponding to the thruster to be tested, and repeat steps S104 to S105 until the gas path polarities of all cathode outlets corresponding to the thruster to be tested are verified. Further, in step S107, by switching the valve of the XFC corresponding to the thruster to be tested, repeat steps S104 to S105. Specifically, in this embodiment, close the valve of XFC-A and switch to open the valve of XFC-B. At this time, cathode B and the anode supply gas, and cathode A does not supply gas. Use a helium mass spectrometer probe to measure the helium concentration at the corresponding cathode outlet respectively, and take the helium concentration at the outlet of the non-gas-supplied cathode A as the reference value according to the measurement result of the helium mass spectrometer probe. When the helium concentration at the outlet of the gas-supplied cathode B is higher than the reference value, it is determined that its gas path polarity is correct. The specific implementation method refers to the foregoing content and will not be elaborated here.

[0053] S108: Sequentially switch to other thrusters and repeat steps S103 to S107 to complete the verification of the gas path polarities of all thrusters. Preferably, when switching to other thrusters, select other thrusters on the opposite side of the star from the thruster to be tested to avoid the influence of helium diffusion on the measurement results. Since the distance between the main and backup thrusters on one side of the star is usually less than 50 cm, and the diffusion rate of helium is extremely fast, the helium concentration on this side may reach saturation after testing the main thruster. Therefore, after measuring the thrusters on one side of the star, measure the thrusters on the other side of the star.

[0054] Specifically, after the measurement of the thruster under test is completed, disconnect the XFC connector of the thruster under test, turn to the other side of the satellite to measure the thruster on the opposite side, and plug in the XFC connector of the thruster on the opposite side, and perform the above steps S103 - S107; in this embodiment, after the measurement of the main Hall thruster on the south side is completed, disconnect the XFC connector of this thruster, then turn to the main Hall thruster on the north side and plug in the XFC connector of the main Hall thruster on the north side, and execute steps S103 - S107; and so on. After the measurement of the main Hall thruster on the north side is completed, turn to the other side of the satellite to measure the other thrusters under test on the opposite side, specifically, turn to measure the backup Hall thruster on the south side. After the measurement of the backup Hall thruster on the south side is completed, then turn to measure the backup Hall thruster on the north side; that is, the purpose of turning to the other side of the satellite for measurement is that: the helium diffusion speed is extremely fast. If the thrusters on the same side are measured at this time, there will be a problem of obscuring the measurement result of the helium concentration.

[0055] After the measurement of the four thrusters in this embodiment is completed, reconnect all the XFC electrical connectors on the satellite and close the corresponding XFC valves. The polarity test is completed.

[0056] The test results of this embodiment are shown in Table 1 below. Table 1 shows the outlet leak rate results of the four Hall thrusters in this embodiment.

[0057] Table 1:

[0058]

[0059] Since only the corresponding XFC cables are plugged in before each test, and the upstream pressure drops after the valve is opened, it indicates that the cable connection of the XFC is correct. There are magnitude differences in the helium leak rates at the outlets of the double cathodes and the anode after each test, indicating that the test results are valid. The leak rate at the outlet of cathode B is in the -7 magnitude, the outlet of cathode A is in the -3 magnitude, and the outlet of the anode is in the -2 magnitude, indicating that the polarities of the cathode and anode gas paths of each XFC are correct.

[0060] Further, in steps S105 and S106, if the helium concentration is close to the measurement upper limit of the mass spectrometer, the test process can be split into multiple times, or the mean value can be taken through multiple measurements to improve the accuracy.

[0061] Since there is a measurement upper limit for the helium mass spectrometer to measure the concentration, it may be that after measuring one thruster, the helium concentration near the entire satellite reaches the upper limit and cannot be measured. The test process can be split into two times; due to different types of helium mass spectrometers for measurement, there is a risk of large errors, which may lead to inaccurate measurement. If the measurement does not meet the requirements, the mean value can be taken through multiple measurements to avoid it.

[0062] The test method described in the present invention can be applied to various types of Hall electric propulsion systems.

[0063] In summary, the method for testing the gas path polarity of the Hall electric propulsion system described in the present invention on a satellite realizes the detection of the gas path polarity of the Hall electric propulsion system after the satellite is fully assembled by means of mass spectrometry analyzer detection and measures such as plugging the thruster outlet and switching the connectors on and off; it solves the problem that the gas path polarity of the Hall electric propulsion system cannot be detected after the satellite is fully assembled, avoids the risk of incorrect connection polarity of the electric propulsion pipeline, and thus improves the reliability and robustness of the electric propulsion system; during the testing process, the pipeline is under positive pressure from upstream to downstream, and all the products used are those used on the satellite, so there is no risk of introducing foreign objects into the interior of the electric propulsion pipeline; the method provided by the present invention can realize the full gas path detection of the electric propulsion pipeline from the upstream gas cylinder to the thruster outlet.

[0064] Certainly, the present invention may also have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and deformations according to the present invention, but these corresponding changes and deformations should all fall within the protection scope of the appended claims of the present invention.

Claims

1. A method for testing the gas path polarity of a Hall electric propulsion system on a satellite, characterized in that: The following steps are involved: (1) Control the gas circuit valve of the Hall electric propulsion system to be in the closed state, fill the pipeline with helium at a pressure higher than the ambient pressure, and fill the upstream buffer gas cylinder with high-pressure helium; (2) Disconnect the electrical connectors of the flow control modules of all Hall electric thrusters on the satellite, and only keep the electrical connector of the flow control module to be verified connected; (3) Seal the anode outlet and each cathode outlet of the thruster to be tested; (4) The entire satellite is powered on, and the valve of the flow control module corresponding to the thruster to be tested is opened to ensure that one of the cathode outlets and the anode outlet is supplied with gas, and the other cathode outlets are not supplied with gas; (5) Use a helium mass spectrometer probe to penetrate the sealing material and measure the helium concentration at the cathode outlet without gas supply and the cathode outlet with gas supply in turn, and compare the two measurement results to verify the cathode gas path polarity; (6) Use a helium mass spectrometer probe to penetrate the sealing material to measure the helium concentration at the anode outlet. If the concentration is higher than that at the cathode outlet, verify that the polarity of the anode gas path is correct. (7) switching the valve of the flow control module corresponding to the thruster to be tested, and repeating steps (4) to (5) until the gas path polarities of all cathode outlets corresponding to the thruster to be tested are verified; (8) Switch to other thrusters in turn and repeat steps (3) to (7) to complete the gas path polarity verification of all thrusters.

2. The gas path polarity testing method according to claim 1, characterized in that: In step (1), the helium pressure inside the pipeline exceeds 0.2 MPa, and the helium pressure in the upstream buffer gas cylinder exceeds 1 MPa.

3. The gas path polarity testing method according to claim 1, characterized in that: In step (3), the sealing adopts a protective film and a sealing tape, wherein the sealing method of the protective film at the anode outlet is different from the sealing method of the sealing tape at the cathode outlet.

4. The gas path polarity testing method according to claim 1, characterized in that: In step (8), when switching to other thrusters, other thrusters on the opposite side of the star body to the thruster to be measured are selected to avoid the influence of helium diffusion on the measurement result.

5. The gas path polarity testing method according to claim 1, characterized in that: In steps (5) and (6), if the helium concentration is close to the upper limit of the mass spectrometer, the test process is split into multiple times, or the average is taken from multiple measurements to improve accuracy.

6. The gas path polarity testing method according to claim 1, characterized in that: After the test is completed, the electrical connectors of all flow control modules are restored and the valves of the corresponding flow control modules are closed.

7. The gas path polarity testing method according to claim 1, characterized in that: In step (5), the measurement result of the helium mass spectrometer probe uses the helium concentration at the cathode outlet without gas supply as a reference value, and when the helium concentration at the cathode outlet with gas supply is higher than the reference value, it is determined that the gas path polarity is correct.

Images