Method for protecting and diagnosing state of low-orbit satellite plasma payload from pollution
By implementing anti-contamination measures during the design, assembly, and operation phases of low-Earth orbit satellite plasma payloads, including the use of titanium alloy plates and heating devices, combined with voltage scanning diagnostics, the problem of sensor contaminant accumulation was solved, improving observation accuracy and data reliability.
Patent Information
- Application Number
- CN202510268849.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-07
- Publication Date
- 2025-11-18
- Estimated Expiration
- 2045-03-07
AI Technical Summary
Low-Earth orbit satellite plasma payload sensors are susceptible to contaminant buildup during on-orbit operation, leading to reduced observation sensitivity and data accuracy issues.
During the design phase, titanium alloy plates are used as the sensor's blocking grid and collecting electrode substrate, and a heating device is installed at the bottom of the conductor extension plate. During the assembly and launch phases, the environmental cleanliness is strictly controlled. During the on-orbit operation phase, the heating device is used to maintain the sensor's local high temperature state, and the contamination status is diagnosed in combination with the voltage scanning mode.
It effectively prevents and rapidly diagnoses contaminant deposition on sensor surfaces, improving the observation accuracy and reliability of low-orbit satellite plasma payloads.
Smart Images
Figure CN120057311B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of orbital satellite technology, and in particular to a method for protecting low-orbit satellite plasma payloads from contamination and for condition diagnosis. Background Technology
[0002] Low Earth orbit (LEO) satellites are those orbiting relatively close to the Earth's surface, at an altitude of approximately 160 to 2000 kilometers. LEO satellites orbit the Earth very quickly, completing one orbit in about 90 to 120 minutes. Due to their proximity to the Earth, they have advantages in Earth observation, scientific experiments, and some communication missions. However, because LEO satellites are affected by atmospheric drag and Earth's gravity, they require frequent orbital adjustments and are therefore susceptible to the accumulation of pollutants caused by factors such as engine exhaust during orbit maintenance.
[0003] Zhangheng-1 01 satellite, launched in February 2018, is China's first independently developed geophysical field satellite, orbiting at an altitude of 507 kilometers. Plasma Analyzer 1 is one of the eight payloads on board the satellite, used for in-situ observation of ionospheric plasma parameters, including ion density, ion temperature, ion drift velocity, ion composition, and ion density fluctuations. All sensors and conductor extension plates in Plasma Payload 1 are mounted on the windward side of the satellite platform, and the sensor inlets are flush with the satellite's surface skin. Figure 2 As shown.
[0004] The plasma analyzer consists of three sensors and a conductor expansion plate in terms of hardware configuration 1.1. These sensors include a retardation potential analyzer 1.2, an ion drift meter 1.3, and an ion trapping meter 1.4. The retardation potential analyzer is used to detect the ionospheric plasma density and temperature, the ion drift meter is used to detect ion drift velocity, the ion trapping meter is used to detect ion density fluctuations, and the conductor expansion plate is mainly used to increase the conductive area and maintain the uniformity of the electric field at the sensor inlet. Figure 3 A schematic diagram of the structure of a low-orbit satellite plasma payload is shown.
[0005] All three sensors in the plasma analyzer are derived from the traditional Faraday cup. Taking the hindrance analyzer as an example, its sensor front opening is circular, with multiple layers of grids inside, and the bottom is the current collecting electrode. The cross-sectional structure is as follows: Figure 4 As shown.
[0006] During satellite flight, space plasma (electrons and ions) enters the instrument through the sensor opening. Inside the sensor, a blocking grid maintains a certain bias voltage relative to the instrument ground to prevent electrons in the space plasma from reaching the collecting electrode, while also preventing secondary electrons and photoelectrons from escaping from the collecting electrode. This ensures that the current detected by the collecting electrode is entirely formed by ions in the plasma. As the scanning bias voltage of the blocking grid gradually changes over time, the collecting electrode can obtain a current-voltage characteristic curve showing the change of ion current with the scanning bias voltage. By fitting the current-voltage characteristic curve, physical quantities such as ion density, ion temperature, and ion drift velocity can be obtained.
[0007] Shortly after the Zhangheng-1 01 satellite entered orbit, an abnormal decrease in the observed values of the plasma analyzer was detected. After analysis and verification, it was confirmed that the blocking grid and collecting electrode of the plasma analyzer sensor were contaminated in orbit, and a contamination layer was formed by the deposition of small components on the surface, which suppressed the sensor collecting current, caused the payload observation sensitivity to decrease, and resulted in the observed ion density being lower than expected.
[0008] Furthermore, influenced by the space plasma environment, positive charges gradually accumulate on the surface of the contamination layer, causing an increase in the positive electric field strength of the contamination layer. This, in turn, repels positively charged ions from passing through the grid normally, thus inhibiting the normal collection of ions by the collector and resulting in a decrease in the on-orbit collection current. Figure 5 As shown.
[0009] Therefore, it is evident that contamination layers adsorbed on the surface of satellite payload sensors can cause decreased observation sensitivity and measurement interference, affecting payload resolution and data accuracy. Thus, protecting satellite payload sensors from the effects of contamination in the space environment is crucial to ensuring the accuracy of low-Earth orbit satellite observation data and the normal operation of the payload. Summary of the Invention
[0010] In view of this, embodiments of the present invention provide a method for pollution protection and condition diagnosis of plasma payloads for low-orbit satellites, which at least partially solves the problems existing in the prior art.
[0011] Other features and advantages of the invention will become apparent from the following detailed description, or may be learned in part by practice of the invention.
[0012] To achieve the above objectives, the embodiments of the present invention provide the following technical solutions:
[0013] According to a first aspect of the present invention, a method for protecting a low-Earth orbit satellite plasma payload from contamination is provided, the contamination protection method comprising:
[0014] During the design phase of the low-Earth orbit satellite plasma payload, the low-Earth orbit satellite plasma payload is modified for contamination protection.
[0015] During the assembly and testing phase of the low-Earth orbit satellite plasma payload, pollution control measures are implemented for the testing environment and protective devices of the low-Earth orbit satellite plasma payload.
[0016] During the on-orbit operation phase of the low-orbit satellite plasma payload, on-orbit contamination protection treatment is carried out on the low-orbit satellite plasma payload.
[0017] Furthermore, the low-orbit satellite plasma payload undergoes contamination protection modifications, including:
[0018] For the conductor extension plate of the low-orbit satellite plasma payload, a heating device is installed at the bottom of the conductor extension plate. The heating device includes a heating element and a thermistor. The heating device has the ability to keep the conductor extension plate heated to 60°C for a long time after the satellite enters orbit.
[0019] Furthermore, the contamination protection modification of the low-orbit satellite plasma payload also includes:
[0020] For the sensor of the low-orbit satellite plasma payload, a titanium alloy plate is used as the retardation grid and the collecting electrode substrate of the sensor, and the coating material on the surface of the titanium alloy plate is titanium nitride.
[0021] Furthermore, the sensor collecting electrode is fixed on a polyimide insulating plate;
[0022] Titanium alloy is used as the material for the external extension rod on the mounting surface of the sensor.
[0023] Furthermore, the sensor includes a retardation potential analyzer, an ion trapping meter, and an ion drift meter. The sensor has a multi-layer grid structure, including multiple retardation grids and a bottom collecting electrode.
[0024] Furthermore, during the assembly and testing phase of the low-Earth orbit satellite plasma payload, contamination control is implemented for the testing environment and protective devices of the low-Earth orbit satellite plasma payload, including:
[0025] The low-orbit satellite plasma payload was assembled and tested in the cleanroom of the assembly plant.
[0026] Before the low-orbit satellite plasma payload is installed into the launch vehicle fairing at the launch site, the inside of the fairing is cleaned using a vacuum cleaner of class 100000.
[0027] During the placement of the low-Earth orbit satellite plasma payload inside the launch vehicle fairing, a protective cover is used to reduce the exposure time of the plasma payload sensor to the non-clean environment inside the fairing. The protective cover on the plasma payload sensor is removed 2 to 4 hours before the launch of the low-Earth orbit satellite.
[0028] Furthermore, the low-orbit satellite plasma payload undergoes on-orbit contamination protection treatment, including:
[0029] In the initial stage of the low-orbit satellite's entry into orbit, except for the brief power-on of the plasma payload to confirm its working status, the plasma payload remains powered off. The heating device on the conductor extension plate of the plasma payload keeps the plasma payload sensor in a local high-temperature state for two months, followed by long-term heating control of 10 to 15 degrees.
[0030] The brief power-on process should be avoided during the jet propulsion period of low-Earth orbit satellites.
[0031] According to a second aspect of the present invention, a method for diagnosing the contamination status of a low-Earth orbit satellite plasma payload is provided, the contamination status diagnosis method comprising:
[0032] According to the preset voltage scanning mode, the contamination status diagnosis process of the low-orbit satellite plasma payload in orbit is performed, and the acquisition current generated by the sensor collecting electrode of the low-orbit satellite plasma payload is obtained.
[0033] If the preset voltage scanning mode is a pollution status check mode, then determine whether the collected current is linearly obliquely symmetrical.
[0034] If the collected current is linearly obliquely symmetrical, then the sensor surface of the low-orbit satellite plasma payload is not covered with a contamination layer.
[0035] If the collected current exhibits a nonlinear, oblique, and asymmetrical shape, the sensor surface of the low-orbit satellite plasma payload will be covered with a contamination layer. The severity of the contamination is determined based on the degree of nonlinear deviation of the collected current. To reduce contamination layer deposition, measures are taken to increase the temperature of the heating element installed on the conductor extension plate in the aforementioned low-orbit satellite plasma payload contamination protection method and to adjust the payload's operating state.
[0036] Furthermore, each voltage scan cycle of the pollution status inspection mode includes a first stage, a second stage, and a third stage;
[0037] In the first stage, the voltage is increased from the reference voltage value to the maximum voltage value;
[0038] In the second stage, the voltage is reduced from the maximum voltage value to the reference voltage value;
[0039] No voltage input is maintained during the third stage.
[0040] Furthermore, the preset voltage scanning mode also includes a normal mode, in which the voltage is increased from the reference voltage value to the maximum voltage value in each voltage scanning cycle of the normal mode;
[0041] In the normal mode, the physical quantity observation value is obtained by inversion calculation based on the combination of scanning voltage value and collected current value.
[0042] This invention provides a method for contamination protection and condition diagnosis of low-Earth orbit satellite plasma payloads. Based on research and demonstration results of sensor contamination phenomena after the plasma analyzer payload onboard the Zhangheng-1 01 satellite entered orbit, this invention systematically proposes contamination protection and diagnosis methods for the entire process of plasma payload structural design, material selection, assembly and testing, on-orbit operation, and condition diagnosis. This invention can effectively prevent and quickly diagnose the deposition of contaminants on the surface of the payload sensors, reduce the degree of contamination damage to the payload sensors in orbit, and significantly improve the observation accuracy and reliability of low-Earth orbit satellite plasma payload data. This invention is highly operable and has significant practical value in satellite engineering implementation. Attached Figure Description
[0043] To more clearly illustrate the embodiments of the present invention or the technical solutions in 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 merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.
[0044] Figure 1 A schematic diagram illustrating the principle of a low-orbit satellite plasma payload contamination protection and condition diagnosis method provided in an embodiment of the present invention;
[0045] Figure 2 This is a schematic diagram of the on-board installation location of the plasma analyzer provided in an embodiment of the present invention;
[0046] Figure 3 This is a schematic diagram of the hardware structure of a plasma analyzer provided in an embodiment of the present invention;
[0047] Figure 4 This is a schematic diagram of the cross-sectional structure of the sensor provided in an embodiment of the present invention;
[0048] Figure 5 A schematic diagram illustrating how a contamination layer affects the abnormal ion collection of a sensor, as provided in an embodiment of the present invention.
[0049] Figure 6 This is a schematic diagram of the conventional voltage scanning mode provided in an embodiment of the present invention;
[0050] Figure 7This is a schematic diagram of the voltage scanning contamination status inspection mode provided in an embodiment of the present invention.
[0051] Figure label:
[0052] 1-Plasma analyzer; 1.1-Conductor extension plate; 1.2-Holding potential analyzer; 1.3-Ion drift meter; 1.4-Ion trapping meter. Detailed Implementation
[0053] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.
[0054] Furthermore, the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion, such that a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or apparatus.
[0055] Analysis of the shortcomings of existing technologies revealed that plasma payload sensors are mainly contaminated through the following pathways: 1. Incompletely burned gas released from the engine nozzle during satellite attitude control and orbit changes gradually forms plume molecular deposition; 2. Small molecule particle deposition caused by the volatilization and release of gas from the satellite's thermal control multilayer materials under high-temperature conditions; 3. Ground pollutants carried on board eventually form physical adsorption on the surface of the satellite.
[0056] This invention, based on the analysis and verification of on-orbit contamination issues of the Zhangheng-1 01 satellite, proposes a method for contamination protection and condition diagnosis of low-orbit satellite plasma payloads. This method protects and controls the deposition of on-orbit contaminants on sensor surfaces, ensuring the satellite payload remains in a relatively clean operating state after entering orbit. Figure 1 The figure shows a schematic diagram illustrating the principle of the low-orbit satellite plasma payload contamination protection and condition diagnosis method provided in an embodiment of the present invention.
[0057] First, this invention provides a method for protecting low-orbit satellite plasma payloads from contamination. The plasma payload is a plasma analyzer, which includes sensors and conductor extension plates. The sensors include a hysteresis potential analyzer, an ion drift meter, and an ion trapping meter.
[0058] First, during the design phase of the low-orbit satellite plasma payload, pollution protection modifications are carried out on the low-orbit satellite plasma payload.
[0059] The above steps specifically include:
[0060] The gold-plated material on the surface of the collecting electrode of the plasma analyzer sensor is prone to contaminant accumulation. By optimizing the collecting electrode material, the sensor's anti-contamination ability can be improved. Based on the experimental comparison results, this embodiment of the invention uses a titanium alloy plate (TC4) as the substrate for the retardation grid and collecting electrode of the sensor of the low-orbit satellite plasma payload. The surface coating material of the titanium alloy plate is titanium nitride (TiN), and the above-mentioned collecting electrode titanium alloy plate is fixed on a polyimide insulating board.
[0061] The embodiments of the present invention select materials with good anti-contaminant deposition properties and apply them to the outer surface of the sensor. The material surface is then specially treated, such as by coating or plating, to prevent contaminant adhesion or reduce the impact of contaminant deposition on the sensor surface through chemical reactions.
[0062] Furthermore, since the plasma payload is installed on the satellite's windward side, materials that are prone to escaping gas or environmental contamination (such as organic materials or materials that easily accumulate static electricity) should be avoided near the mounting surface to prevent the release of adsorbable pollutants that could adhere to the sensor surface. The extension rods installed around the sensor mounting surface should avoid using carbon fiber materials, as there is a possibility that carbon fiber particles may erode and detach, entering the sensor and causing small particles to accumulate and adhere.
[0063] In this embodiment of the invention, the external extension rod material on the mounting surface of the sensor of the low-orbit satellite plasma payload is replaced with titanium alloy material (TC4), which has sufficient strength and stability, can effectively avoid material erosion and detachment, and can meet the mechanical characteristics requirements and pollution protection requirements of the satellite active phase.
[0064] Furthermore, because the opening of the plasma analyzer sensor is exposed on the satellite's surface, the sensor is surrounded by the satellite's temperature control layer. In the initial stages of orbit insertion, under the high temperatures of space sunlight, the temperature control layer material will volatilize a large amount of colloidal small molecular particles, which easily adhere to the sensor surface. In addition, to maintain a relatively stable orbital altitude, low-Earth orbit satellites periodically activate their engines for orbit maintenance. The main components of the satellite engine propellant are hydrazine and water. In the space environment, hydrazine decomposes to produce plumes of nitrogen (N2), ammonia (NH3), monomethylhydrazine (MMH-HNO3), and other organic molecules, which undergo a deposition process upon contact with the sensor surface, easily forming physical adsorption.
[0065] Based on the principle of gas condensation and deposition, small organic molecules in the space environment tend to move from high-temperature regions to low-temperature regions. On the other hand, the adsorption time of pollutants on the surface of a star is mainly determined by the material properties of the adsorption surface and the surface temperature.
[0066] Therefore, the temperature of the sensor surface determines the adsorption time and deposition thickness of pollutant organic molecules on the surface of the satellite payload sensor.
[0067] To address this, this embodiment of the invention includes a heating device installed at the bottom of the conductor extension plate of the low-Earth orbit satellite plasma payload. This heating device comprises a heating element and a thermistor. After the satellite enters orbit, the heating device is activated via ground command to heat the conductor extension plate, ensuring its surface temperature is significantly higher than that of other parts of the satellite's windward side, thereby preventing gases released by the satellite from depositing on the sensor surface.
[0068] Research has found that the volatilization of small molecule particles from the satellite's temperature control multilayer material is more intense in the early stages of satellite launch, and then gradually decreases over time. In addition, the satellite needs to perform multiple orbital adjustments in the early stages of launch, resulting in frequent engine firing and the release of a large number of gas molecules.
[0069] Therefore, in the initial stage of satellite insertion into orbit, the heating temperature of the conductor extension plate is controlled at around 60°C to ensure that small molecular particles are not adsorbed. About two months after insertion, long-term heating is carried out at around 10 to 15°C, with the specific temperature setting determined based on the actual situation in orbit.
[0070] The sensor inside the plasma payload of the low-orbit satellite has a multi-layer grid structure. The blocking grid maintains a negative bias voltage relative to the instrument ground to prevent electrons in the space plasma from reaching the collector electrode, while preventing secondary electrons and photoelectrons on the collector electrode from escaping, so as to ensure that the current detected by the collector electrode is entirely formed by ions in the plasma.
[0071] Next, during the assembly and testing phase of the low-Earth orbit satellite plasma payload, pollution control measures were implemented for the testing environment and protective devices of the low-Earth orbit satellite plasma payload.
[0072] The above steps specifically include:
[0073] Since one of the contamination pathways for plasma payload sensors is the physical adsorption of ground contaminants on the surface of the satellite, environmental cleanliness must be controlled during ground assembly and testing.
[0074] First, load-bearing components are assembled and related tests are conducted in the cleanroom of the assembly plant to ensure that the content of dust particles in the air is extremely low, thereby reducing particulate pollution.
[0075] Next, the cleanliness inside the launch vehicle fairing is controlled. After the fairing arrives at the launch site, it is thoroughly cleaned. A special Class 10000 vacuum cleaner is used to clean the inside of the fairing in front of the fairing opening to prevent dust particles from the ground environment from entering the payload sensors.
[0076] Furthermore, because the plasma analyzer sensor is installed on the windward side of the satellite, the fixed position of the satellite causes the sensor opening to face the factory ceiling. Therefore, a protective cover is installed on the sensor to prevent dust particles from the factory ceiling and the space environment from directly falling into the sensor during the long-term placement of the satellite. Since the weakest link in the protection against ground contaminants is the process of placing the satellite in the launch vehicle fairing before launch, this embodiment of the invention reduces the sensor's exposure time in a non-clean environment by delaying the removal of the protective cover. A dedicated access port is added inside the launch vehicle fairing to remove the protective cover device on the plasma analyzer sensor 2 to 4 hours before satellite launch.
[0077] Finally, during the on-orbit operation phase of the low-Earth orbit satellite plasma payload, on-orbit contamination protection measures are implemented for the low-Earth orbit satellite plasma payload.
[0078] The above steps specifically include:
[0079] Because the volatilization of small-molecule particles from the satellite's temperature-controlled multilayer materials is relatively intense during the initial stage of satellite insertion into orbit, gradually decreasing over time, and because multiple orbital adjustments are required during this initial stage, resulting in frequent engine firings and the release of a large number of gas molecules, the electric field generated by the voltage applied to the blocking grid after the payload sensors are activated easily attracts small-molecule particles to adhere to the satellite. Therefore, it is necessary to control the timing of payload activation after satellite insertion into orbit.
[0080] During the initial orbital insertion phase, except for brief power-ups to confirm the plasma payload's operational status, the plasma payload remained powered off. During this period, heating devices on the plasma payload's conductor extension plate maintained the plasma payload sensors at a locally high temperature, reducing the possibility of contamination due to gas condensation and deposition. It should be noted that brief power-ups were avoided during the low-Earth orbit satellite's exhaust phase. After maintaining the conductor extension plate at a high temperature of 60°C for two months following orbital insertion, long-term heating control was implemented at approximately 10 to 15°C, and the conductor extension plate heating temperature was further determined based on the payload contamination analysis results.
[0081] In addition, embodiments of the present invention also provide a method for diagnosing the contamination status of a low-orbit satellite plasma payload, including:
[0082] After the low-Earth orbit satellite plasma payload is powered on, in normal voltage mode, the voltage increases linearly from a reference value to a maximum value per second to complete one full cycle of voltage scanning (scanning upwards at an angle). Then, the next cycle of voltage scanning begins. The scanned voltage value is combined with the current value collected by the collector to obtain the observed physical quantities through inversion calculations, such as... Figure 6 As shown.
[0083] In order to quickly determine whether the sensor is in a contaminated state so as to take timely measures to reduce the impact of contamination, this embodiment of the invention performs a contamination state check voltage scan (up and down scan) on the low-orbit satellite plasma payload to obtain the acquisition current generated by the sensor collecting electrode of the low-orbit satellite plasma payload.
[0084] The above-mentioned contamination status inspection voltage scan consists of three phases: the first second, the voltage rises from the reference value to the maximum value to complete the voltage "upward sweep"; the second second, the voltage drops from the maximum value to the reference value to complete the voltage "downward sweep"; and the third second, the voltage remains stationary with no voltage output, then the next voltage scan cycle begins. Figure 7 The figure shows a schematic diagram of voltage scanning for contamination status inspection.
[0085] To determine whether the collected current exhibits a linear oblique symmetrical shape, under ideal conditions, the sensor is in a purely resistive state. Therefore, during the "up and down sweep" of the scanning voltage in the contamination state inspection mode, the collected current generated by the sensor's collector exhibits a linear oblique symmetrical shape.
[0086] If the sensor surface is covered with a contamination layer, the sensor becomes a non-pure resistive state. Under the resistive-capacitive effect of the contaminants, the collection current generated by the collecting electrode exhibits a non-linear, oblique, and asymmetrical shape. The greater the degree of non-linear deviation, the more severe the contamination. This allows for a rapid diagnosis of the sensor's contamination status, obtaining the contamination status diagnosis result, and corresponding measures such as increasing the temperature of the conductor extension plate heating element and adjusting the working status can be taken.
[0087] The switching between the above-mentioned conventional mode and the pollution status inspection mode is achieved through ground command injection.
[0088] In summary, the low-Earth orbit satellite plasma payload contamination protection and condition diagnosis method provided in this invention is based on the research and demonstration results of sensor contamination phenomena after the plasma analyzer payload carried by the Zhangheng-1 01 satellite entered orbit. It systematically proposes contamination protection and diagnosis methods for the entire process of plasma payload structural design, material selection, assembly and testing, on-orbit operation, and condition diagnosis. This invention can effectively prevent and quickly diagnose the deposition of contaminants on the surface of the payload sensors, reduce the degree of contamination damage to the payload sensors in orbit, and significantly improve the observation accuracy and reliability of low-Earth orbit satellite plasma payload data. This invention can be applied to the design and development of plasma analyzer payloads carried by subsequent Zhangheng-1 satellites, and is also applicable to plasma observation payloads of similar types of low-Earth orbit satellites. In terms of satellite engineering implementation, this invention has the characteristics of high operability and great practical value.
[0089] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.
[0090] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, equivalent changes, or alterations made by those skilled in the art using the disclosed technical content shall fall within the protection scope of the present invention.
Claims
1. A method for diagnosing the contamination status of a low-orbit satellite plasma payload, characterized in that, The pollution status diagnosis method includes: According to the preset voltage scanning mode, the contamination status diagnosis process of the low-orbit satellite plasma payload in orbit is performed, and the acquisition current generated by the sensor collecting electrode of the low-orbit satellite plasma payload is obtained. If the preset voltage scanning mode is a pollution status check mode, then determine whether the collected current is linearly obliquely symmetrical. If the collected current is linearly obliquely symmetrical, then the sensor surface of the low-orbit satellite plasma payload is not covered with a contamination layer. If the collected current exhibits a nonlinear, oblique, and asymmetrical shape, the sensor surface of the low-orbit satellite plasma payload will be covered with a contamination layer. The severity of the contamination is determined based on the degree of nonlinear deviation of the collected current. To reduce contamination layer deposition, measures are taken to increase the temperature of the heating element installed on the conductor extension plate and adjust the working state of the payload in a low-orbit satellite plasma payload contamination protection method. The method for protecting low-orbit satellite plasma payloads from contamination includes: During the design phase of the low-Earth orbit satellite plasma payload, the low-Earth orbit satellite plasma payload is modified for contamination protection. The modification for contamination protection of the low-Earth orbit satellite plasma payload includes: for the conductor extension plate of the low-Earth orbit satellite plasma payload, a heating device is installed at the bottom of the conductor extension plate. The heating device includes a heating element and a thermistor. The heating device has the ability to keep the conductor extension plate heated to 60°C for a long time after the satellite enters orbit. During the assembly and testing phase of the low-Earth orbit satellite plasma payload, pollution control measures are implemented for the testing environment and protective devices of the low-Earth orbit satellite plasma payload. During the on-orbit operation phase of the low-Earth orbit (LEO) satellite plasma payload, on-orbit contamination protection measures are implemented. These measures include: during the initial orbital period after the LEO satellite enters orbit, except for brief power-on to confirm its operational status, the plasma payload remains powered off. Heating devices on the plasma payload's conductor extension plate maintain the plasma payload sensors at a locally high temperature for two months, followed by long-term heating control at 10-15°C. Brief power-on is avoided during the jet propulsion period of the LEO satellite's attitude control propulsion engine.
2. The method for diagnosing the contamination status of a low-orbit satellite plasma payload as described in claim 1, characterized in that, The contamination protection modification of the low-orbit satellite plasma payload also includes: For the sensor of the low-orbit satellite plasma payload, a titanium alloy plate is used as the retardation grid and the collecting electrode substrate of the sensor, and the coating material on the surface of the titanium alloy plate is titanium nitride.
3. The method for diagnosing the contamination status of a low-orbit satellite plasma payload as described in claim 2, characterized in that, The sensor collecting electrode is fixed to a polyimide insulating plate; Titanium alloy is used as the material for the external extension rod on the mounting surface of the sensor.
4. The method for diagnosing the contamination status of a low-orbit satellite plasma payload as described in claim 2, characterized in that, The sensor includes a retardation potential analyzer, an ion trapping meter, and an ion drift meter. The sensor has a multi-layer grid structure, including multiple retardation grids and a bottom collecting electrode.
5. The method for diagnosing the contamination status of a low-orbit satellite plasma payload as described in claim 1, characterized in that, During the assembly and testing phase of the low-Earth orbit satellite plasma payload, contamination control is implemented for the testing environment and protective devices of the low-Earth orbit satellite plasma payload, including: The low-orbit satellite plasma payload was assembled and tested in the cleanroom of the assembly plant. Before the low-orbit satellite plasma payload is installed into the launch vehicle fairing at the launch site, the inside of the fairing is cleaned using a vacuum cleaner of class 100000. During the placement of the low-Earth orbit satellite plasma payload inside the launch vehicle fairing, a protective cover is used to reduce the exposure time of the plasma payload sensor to the non-clean environment inside the fairing. The protective cover on the plasma payload sensor is removed 2 to 4 hours before the launch of the low-Earth orbit satellite.
6. The method for diagnosing the contamination status of a low-orbit satellite plasma payload as described in claim 1, characterized in that, Each voltage scan cycle of the pollution status inspection mode includes a first stage, a second stage, and a third stage; In the first stage, the voltage is increased from the reference voltage value to the maximum voltage value; In the second stage, the voltage is reduced from the maximum voltage value to the reference voltage value; No voltage input is maintained during the third stage.
7. The method for diagnosing the contamination status of a low-orbit satellite plasma payload as described in claim 1, characterized in that, The preset voltage scanning mode also includes a normal mode, in which the voltage is increased from the reference voltage value to the maximum voltage value in each voltage scanning cycle of the normal mode; In the normal mode, the physical quantity observation value is obtained by inversion calculation based on the combination of scanning voltage value and collected current value.