High-voltage flexible solar arrays are critical for high-power spacecraft and large-scale space facilities due to their reduced transmission losses and lightweight advantages. However, electrostatic discharge (ESD) induced by space plasma remains a major reliability constraint under high-voltage operation. This work proposes a material-driven mitigation strategy for space solar arrays that suppresses ESD susceptibility through dielectric modulation and integrated encapsulation. Dielectric matching between pseudomorphic glass (PMG) and the substrate enables interfacial electric field regulation. The integrated encapsulation strategy further eliminates triple-junction regions, altering ESD-prone regions and interrupting the evolution toward permanent sustained arc (PSA). The flexible solar array maintains electrical performance comparable to rigid panels while offering reduced mass and volume. Meanwhile, compared with traditional coverglass-encapsulated rigid panels that experience PSA at 110 V, the proposed PMG-integrated flexible solar array exhibits no PSA events at 800 V under equivalent conditions. Apparently, the high-voltage flexible solar array in this study exhibits significant potential for enabling efficient and reliable space power generation, holding the promise for assuming a significant role in future space energy systems.

Carbon nanotubes (CNTs) are a type of field emission cathode material with broad application potential. Compared with hot filament cathodes, CNTs cathodes possess advantages such as low operating temperature and energy efficiency. In this article, a CNTs electron emitter is integrated into an ionization gauge featuring a straight electron path. A series of tests were performed on the CNTs cathode and the prototype gauge. The optimal operating potential of the prototype gauge was determined through simulations and experiments. The prototype achieved a sensitivity of 0.317 Pa-1 in argon and 0.240 Pa-1 in nitrogen. This prototype gauge exhibits good linearity in the range from 10-6 Pa to 10-3 Pa in argon and nitrogen, while its sensitivity fluctuations are 1.17 % and 3.2 %, and within half an hour, the sensitivity fluctuations in the two gases are 1.6 % and 2.2 % respectively. Under simulated normal operating conditions, the repeatability is less than 3 %. This novel developed ionization gauge has simultaneously achieved high sensitivity and good stability. This study provides insights for the application of CNTs cathodes in the ionization gauges.

Aiming at the application requirements of brightness temperature calibration of the hot calibration target of spaceborne microwave radiometer, and based on the temperature gradient characteristics of the absorbing coating of the calibration target and the mechanism of brightness temperature deviation, combined with practical temperature measurement and experimental methodology, a brightness temperature metrological calibration technology solution applicable for in-orbit use is studied. Given the current background of high emissivity design and determination technology of the calibration target being basically perfected, this work focuses on summarizing the methods for determining the temperature gradient characteristics of the calibration target coating. The goal is to construct an in-orbit available brightness temperature calibration method that uses multiple parameters, such as the measurable temperature values of the metal inner core of the calibration target and that near the radiation aperture of the calibration target. Based on feasible electromagnetic simulation technology, thermal simulation technology, platinum resistance and infrared temperature measurement techniques, the paper preliminarily summarizes the implementation path of the brightness temperature calibration technology system for space-borne calibration targets. This involves first constructing a basic brightness temperature calibration model considering uniform background brightness temperature and improving the mapping relationship from the inner core temperature of the calibration target and the equivalent background brightness temperature to the longitudinal temperature gradient of the coating. Subsequently, an application model for brightness temperature calibration considering the installation environment is constructed, improving the mapping relationship from the temperature measurements of the inner core and that of the radiation aperture area of calibration target to the overall brightness temperature deviation. Finally, the validation and application of the brightness temperature calibration model are discussed. The research on brightness temperature calibration of space-borne calibration source is an important technical basis and reference for further improving the accuracy of brightness temperature of calibration target and even developing space microwave radiation measurement standards.

Ground-based thrust testing plays a critical role in space missions. While precision thrust measurement under light loads has advanced over the past five years, achieving comparable accuracy under heavy loads remains challenging due to disturbances such as base tilt, ground vibrations, and thruster-induced eccentric moments. In this study, a novel counterbalanced thrust stand with decoupled response to micro thrust under heavy load has been developed. The coupling principles of base tilt and ground vibrations along different axes have been characterized, and a decoupling strategy based on center- of-mass adjustment is proposed. The impact of mass offset on measurement accuracy is further analyzed, and a dual-parallelogram configuration is introduced to eliminate the eccentric moments. Disturbance modulation experiments were conducted, validating the proposed decoupling method. With the optimized configuration, the stand achieves a resolution of 0.02 & micro;N under 8 kg load, with a range of 0.02-275 & micro;N. Additionally, the developed stand was used for thrust testing of a micro Hall thruster, achieving a thrust range of 30.29-89.05 & micro;N with an expanded uncertainty of 1.18%. This study offers meaningful guidance for the design of micro-force sensors under heavy-load conditions.

HCGs are widely used for ultra-high vacuum and space vacuum measurements due to their high-sensitivity and long-term stability. However, the indicated pressure of an HCG may deviate from the actual chamber pressure because the operating conditions during application differ from those during calibration. This deviation is particularly relevant for balance-chamber HCGs used in space vacuum measurements, where the ionization region is connected to the external vacuum environment through multistage conductance channels, leading to complex molecular transport behavior. In this study, the pressure deviation mechanism of balance-chamber HCGs is investigated by considering the coupled effects of thermal transpiration, thermal outgassing, and structural conductance. Based on free molecular flow theory and the Maxwell–Boltzmann velocity distribution, a pressure model is developed to describe the relationship between the internal gauge pressure and the external chamber pressure. The contributions of temperature gradients, outgassing sources, and structural parameters are analyzed through numerical simulations and experimental measurements. The results indicate that thermal transpiration is the dominant factor affecting pressure deviation at relatively higher pressures. With decreasing pressure, thermal outgassing from heated internal components becomes increasingly significant and limits the measurement accuracy in the ultra-high vacuum range. A structure-dependent correction exponent was introduced to account for the influence of the balance chamber on thermal transpiration behavior. After correction, the prediction deviation of the proposed model is reduced to within ±1%. The proposed model provides a quantitative approach for evaluating pressure deviations in HCGs with complex internal structures and improves the reliability of pressure interpretation for space vacuum measurements

The developed MEMS capacitance diaphragm gauge (CDG) features a single-capacitance structure and operates in an electrostatic servo mode for vacuum measurement. In this mode, a servo voltage is applied between the diaphragm and the fixed electrode to electrostatically restore the diaphragm to its initial position; the applied voltage then serves as the pressure-dependent output. Both simulation and experimental results validate the working principle. Compared with the non-servo mode, the servo mode provides stable measurements, replaces capacitance-change detection with a constant-capacitance servo loop, and maintains a constant sensitivity over a wide pressure range. Over 1–1000 Pa, the non-servo mode exhibits a sensitivity that drops from 0.04 pF/Pa to 0.01 pF/Pa, with hysteresis errors of 26.49% and 20.97% obtained in two separate tests. In the servo mode, the sensitivity stays constant at 3.4 V2/Pa, and the hysteresis errors in two corresponding tests are reduced to 2.00% and 2.19%, respectively. These results demonstrate that the servo mechanism significantly enhances measurement linearity and suppresses hysteresis.

Mare basalt is extensively distributed across the lunar surface and represents a primary target for in-situ resource utilization and engineering activities. In this paper, low-power microwave irradiation and mechanical fragmentation experiments were conducted using a characterized simulated mare basalt material. First, a similarity evaluation index system was established to assess the representativeness of simulated mare basalt. Based on this framework, a representative sample (NEU-MB1) with texture and chemical composition closely resembling that of real mare basalt was selected. Its similarity in electromagnetic and thermal parameters was further analyzed in relation to microwave interaction mechanisms. Subsequently, low-power microwave irradiation experiments were performed on NEU-MB1 to investigate its heating characteristics and fracture evolution. Finally, fragmentation tests were conducted on NEU-MB1 before and after microwave irradiation using three types of rock-breaking cutters: roller cone, PDC, and metal button cutters. Comparative analyses were conducted on drilling thrust, torque, displacement, and debris particle size distribution. Results indicate that NEU-MB1 exhibits high similarity to real mare basalt in terms of texture, composition, and electromagnetic-thermal properties. Its vesicular texture significantly influences microwave response, leading to high heating efficiency with limited macroscopic damage. Among the three cutters, the PDC cutter demonstrated the lowest thrust, as well as the highest fragmentation efficiency. As rock strength decreased after irradiation, the mechanical parameters required for fragmentation declined, highlighting the advantage of shearing fragmentation under low-thrust conditions. These findings provide a basis for the development of novel lunar rock-breaking technologies suitable for extreme lunar environments.

The Moon harbors abundant critical mineral resources, including water ice, ilmenite and helium-3 (He). Exploiting these resources holds significant strategic value for sustaining deep-space exploration missions, addressing future resource scarcity, and catalyzing new space-based economic models. This study introduces the reserves and occurrence characteristics of key lunar mineral resources such as water ice, solid minerals, and He. It identifies major challenges in lunar resource utilization, including the harsh extreme lunar environment, uncertainty in resource distribution,limitations of energy supply systems, and reliability of robotic equipment. Based on this, the study reviews research progress in the utilization technologies of key lunar mineral resources, summarizes the full-process technological system forlunarresourcedevelopmentand utilization, and putsforward developmentsuggestionsinareas suchas interdisciplinarytalentdevelopment, exploitation strategies, technical verification, feasibility studies, policies and regulations, and international cooperation models.

The miniaturization of electrospray thrusters for micro-nanosatellites is hampered by a limited understanding of how thruster geometry and operational parameters influence performance in high-conductivity ionic liquid systems. To address this, our study introduces an integrated approach combining computational fluid dynamics with time-of-flight experiments to systematically decouple and optimize the key parameters-emission voltage, propellant flow rate, and emitter-extractor spacing-for a miniaturized thruster design. Our results quantitatively demonstrate that an optimized configuration (8000 V, 2.0 nL/s) achieves a high-efficiency regime, producing 450 mu N of thrust, a specific impulse of 424.7 s, and a remarkable efficiency of 88%. This work provides a validated design framework and performance benchmarks, offering a clear pathway for engineering highperformance, miniaturized electrospray thrusters.

We have developed an optical vacuum pressure standard (OVPS) based on the refractive index of gas. The OVPS consists of two Fabry-Perot (FP) cavities with dimensionally stable spacing, a temperature control system, an optical system, and a vacuum system. During typical operation, two 780 nm tunable diode lasers are frequency-locked to the cavities, utilizing the beat frequency variation between the two resonant laser frequencies to characterize gas pressure measurements. The performance of the OVPS was investigated, including thermal expansion effects and aging. The cavity temperature is 299.1485 K, with temperature fluctuations evaluated to be within +/- 1 mK. Pressure measurements from the OVPS and the piston gauge (PG) were compared across the 10 kPa-100 kPa range. Results showed relative differences within 4.2 & times; 10-5 and repeatability differences within 5.9 & times; 10-5 between the two instruments. Finally, the uncertainty of the OVPS was evaluated as [(54 mPa)2+(78 & times; 10-6p)2]1/2(k = 2).

China's Chang'e-7 lunar mission is scheduled to launch in the second half of 2026. One of its core scientific objectives is to detect the abundance of water ice at the lunar south pole, as well as the composition and abundance of volatiles such as CH4. Lunar regolith will be extracted from a depth of 1 meter in permanently shadowed regions (PSRs) at the lunar south pole and heated in a furnace. The gas generated during heating will be introduced into a mass spectrometer to measure the composition and abundance of the released gases. A mass-spectrometry-based lunar regolith measurement system was developed, enabling lunar regolith heating, pressure measurement in the tubing assembly, and gas composition analysis. A method and procedure for measuring the H2O content in lunar regolith were proposed. The composition and content of H2O and volatiles are determined by analyzing the main and secondary peaks in the gas mass spectrum, their abundance ratios relative to the main peak, and the ion currents of the main and secondary peaks. The mass axis, gas sensitivity, and relative sensitivity of the mass spectrometer were calibrated. A method was proposed to calibrate the zero point of the MEMS capacitive thin-film vacuum gauge in orbit using a Pirani vacuum gauge, and the sensitivity of the mass spectrometer was improved by increasing the microchannel plate (MCP) voltage. Measurements with simulated H2O-bearing lunar regolith verified that the mass spectrometer can accurately measure the H2O content in lunar regolith.

China's Chang'e−7 (CE-7) mission is scheduled for launch in 2026. One of its primary scientific objectives is the in situ detection and quantitative analysis of water ice abundance in permanently shadowed regions (PSRs) at the lunar south pole using a time-of-flight mass spectrometer (TOF-MS). An integrated TOF-MS system has been developed for this purpose. Considering the sampling mass of lunar regolith and the expected range of H2O content, a dual-orifice inlet system was designed to improve both operational safety and measurement accuracy for in-orbit analysis. A labyrinth baffle structure was incorporated into the exhaust line, and a porous mesh filter was installed at the exhaust outlet to prevent lunar dust ingress and ensure stable instrument performance. Based on the upper detection limit of the TOF-MS and the conductance of the vacuum tubing assembly, the allowable conductance range of the inlet orifices was determined. System calibration of the CE-7 TOF-MS was performed, and the results demonstrate stable response and good repeatability. The vacuum tubing assembly parameters are appropriately designed, enabling accurate measurement of H2O content in lunar regolith from PSRs at the lunar south pole.

The existence of water ice at the lunar south pole has become a major topic in contemporary deep-space exploration. China's Chang'e-7 lunar mission is scheduled for launch in 2026. One of its primary scientific objectives is to conduct an in situ investigation of water ice within a permanently shadowed crater at the lunar south pole. The candidate landing site is located near the Shackleton crater. During the exploration, lunar regolith samples will be drilled to a depth of approximately 1 m within the permanently shadowed crater at the lunar south pole and transferred to a furnace to be heated to 200 °C. The H2O and other volatile components released during heating will be introduced into the LSWMA, Lunar Soil Water Molecule Analyzer, which will measure the composition and amount of gases released from the lunar regolith. We developed the LSWMA and established a ground-based mass spectrometer calibration device capable of calibrating gas-liquid mixtures. The flight model of the mass spectrometer was calibrated using CO2 and H2O under different temperatures and inlet pressures. The sensitivity of CO2, S*(I/p)CO2, and the sensitivity of H2O, S*(I/p)H2O, were obtained under different pressures and temperatures, and the relative sensitivity of CO2 to H2O, Sr, was then calculated. Under molecular-flow inlet conditions, the mass spectrometer's relative sensitivity remains constant. Based on this principle, the sensitivity of H2O can be extrapolated from the sensitivity of CO2 under on-orbit conditions. Ultimately, this allows for the accurate inversion of the partial pressure of H2O gas in the tubing assembly and the H2O content of the lunar soil.

The Taiji program is a space-borne gravitational wave detection project conducted in heliocentric orbits, utilizing micro-thrusters for drag-free control to maintain satellites in an ultraquiet and ultrastable state. High-precision and wideband ground evaluation of the thrusters is crucial. As the mass of micro-propulsion systems increases, this imposes requirements for low thrust-to-weight ratios and low noise on micro-thrust measurement devices. This article develops a flexible inverted pendulum-based micro-thrust measurement device capable of handling heavy loads. With an experimental mass of 8 kg, by adjusting the center of mass to coincide with the center of the flexible element, the system's elastic restoring force is provided solely by the flexible element, ultimately achieving a minimum resolution of 0.05 & micro;N for the sub-micro-Newton thrust measurement system. The background noise is better than 0.1 & micro;N/Hz(-1/2) in the 0.1-mHz-1-Hz range, partial frequency point dynamic thrust inversion tests were also conducted, providing a strong ground testing foundation for the engineering implementation of the Taiji program

Spinning-rotor gauges (SRGs) use a magnetically levitated, conductive sphere accelerated by a rotating field; pressure is inferred from the subsequent speed decay. Emerging uses, such as composite gauge stacks and high-pressure start-up, demand predictable torque versus drive frequency, yet a concise, measurement traceable framework that turns frequency into a design knob has been lacking. We develop a physics-based, parameterized model that factorizes torque into a material term, the sphere's loss component .''(!), and an electrical term set by the inverter and the coil's parallel-equivalent inductance. Using measured terminal fundamental voltage V(f) and inductance Lp(f), a single geometric gain calibrated at 15.5 kHz from a short open loop sweep yields an explicit logarithmic peak condition that explains the unique interior "torque window" and its shifts without multi-parameter fitting. Building on this, we implement a frequency scheduler (with a fixed-frequency baseline) and a dual-window hysteresis regulator. Frequency-sweep experiments show the model accurately predicts acceleration-frequency (dv/dt-f) curves and transfers across coil sets and rotor variants without re-calibration. Closed loop tests achieve stable regulation from 440 to 1000 Hz with fewer re-acceleration bursts and low ripple. Under elevated gas load, start-up and sustained control are maintained up to 252 Pa. The framework is portable and metrologically traceable, providing a quantitative rule for frequency placement in SRG designs targeting composite regulation and high-pressure operation.

Abstract High-precision time–frequency standards play vital roles in fundamental physics, geodesy, navigation, and communication. This paper reports experimental progress on an optical frequency standard (OFS) based on the 5S 1/2 → 5D 5/2 two-photon transition in 87 Rb. A 1556 nm communication-band laser is frequency-doubled to generate a 778.1 nm clock laser, which excites Rb atoms via counter-propagating beams. The 420 nm fluorescence is collected to obtain a high signal-to-noise-ratio transition spectrum. The effects of laser power and vapor cell temperature on the fluorescence intensity were systematically investigated. The impact of laser beam waist and atomic collisions on frequency shifts was analyzed. Results show that replacing a tightly focused beam with a large collimated one reduced the laser power-induced frequency shift by two orders of magnitude. Furthermore, increasing the vapor temperature enhances collision-induced frequency shifts, adversely affecting long-term stability. Under optimized conditions, the system achieved a short-term fractional frequency stability of 2.6 × 10 −13 at 1 s, reaching 5.3 × 10 −15 at 10 000 s. This work lays a critical technical foundation for the development of compact and high-performance OFSs.

Thermal mass flow meters are broadly used in different parts of industry for flow metering objectives. One of the most widely used thermal flow meters is capillary tube type. Aiming at the traditional thermal flow sensor, which has the problems of low flow measurement accuracy and temperature drift, based on the principle of fluid flow and heat transfer, a double-winding distributed thermal flow sensor with constant temperature operation is developed. The thermal flow measurement principle is studied and the sensor temperature field is simulated by COMSOL software. The effect of ambient temperature on the measurement results under different structural parameters and operating parameters is investigated by simulation. The optimal sensor operating parameters are determined, and the sensor temperature adaptability is improved. In addition, under the condition of structural error, the influence of structural error on the measurement is analyzed. Simulation calculations are carried out at different ambient temperatures to obtain the corrected relationship between the measured value and the ambient temperature. Finally, according to the simulation results, the sensor is designed and processed, and tested by the standard flow output device. The temperature correction algorithm is obtained according to the experimental results. And the effectiveness of this temperature correction algorithm is verified under different ambient temperatures and different flow inputs. The experiments show that through this correction algorithm, the test error of the sensor has been significantly reduced in the range of the sensor, and the temperature adaptability of the sensor has been improved.

The mysterious u201Clunar horizon glowu201D observed in the 1960s and 1970s was the first space observation possibly related to electrostatic dust transport; however, are there really large amounts of electrostatically transported dust particles in the lunar near-surface space? This is largely an open question at present. Here, we first report the in situ investigation results for the charged dust particles obtained by the charged dust detector onboard Chinau2019s Changu2019E-5 (CE-5) mission. The results show that, within the detectoru2019s detection limit, there are almost no charged dust particles with chargeu2013mass ratios greater than ~0.24 to ~1.96 C/kg and velocities less than ~0.56 to ~0.07 m/s as the scanning voltage decreases from 80 to 10 mV at the location of ~2 m above the CE-5 landing site as the solar elevation angle elevated from ~41.8u00B0 to ~45.0u00B0, under the framework of the dynamic fountain model. Additionally, the upper limit for the amounts of dust deposited on the detector during the exploration period of ~12 h is ~8.0 u00D7 10u22122 u03BCg/cm2.

In this work, a lunar dust detector using a space triple-junction GaInP/GaAs/Ge solar cell equipped with a radiation-resistance silica coverslip and a bead-like thermometer is developed, and its response to the deposited lunar dust simulants under different light incidence angles is investigated experimentally. The results indicate that the short-circuit current reduction is not only deposition mass-dependent, but is also related to the light incidence angle, and a 50% reduction in short-circuit current was achieved by depositing approximately 3.0 mg/cm(2) lunar dust simulants as the sunlight is incident normally. Finally, a physical model, according to the experimental results, was proposed to forecast the impact of dust deposition on the short-circuit current of the triple-junction GaInP/GaAs/Ge solar cell in the lunar surface environment. This model is in good agreement with the experiment results obtained at small incidence angles (0 degrees similar to 50 degrees), with a relative error of less than 1% in this range. This work will help in designing future photovoltaic energy system for lunar surface application and developing strategies for dust mitigation on the lunar surface.

The lightweight nature and exceptional temperature resistance of titanium (Ti) render it a highly favored material for spacecraft applications. However, Ti is susceptible to various corrosion phenomena, particularly hydrogen embrittlement, which can significantly impact the functionality and lifespan of spacecraft. As experimental methods encounter challenges when investigating the internal mechanism of rapid-onset hydrogen embrittlement, we employ a molecular dynamics approach to explore the adsorption, diffusion, and dissociation behavior of hydrogen atoms and molecules (H/H2) on Ti metal surfaces and oxidation products. The adsorption energies of the four bound forms, H-Ti, H-TiO2, H2-Ti, and H2-TiO2, during adsorption are 7.577 eV (hcp), 0.608 eV (bridge), nearly 0 eV, and 0.1127 eV (bridge), with maximum energy barriers for diffusion/dissociation of 1.045 eV, 2.694 eV, 0.3735 eV, and 2.612 eV, respectively. Thus, Ti metal readily undergoes chemical adsorption with hydrogen atoms while promoting dissociation of molecular hydrogen on its surface. Consequently, hydrogen adsorption onto the Ti metal surface and subsequent entry of hydrogen atoms into its bulk structure are enhanced, ultimately increasing susceptibility to hydrogen embrittlement. However, adsorption is limited once Ti metal oxidizes to form a protective surface layer of TiO2 due to reduced reactivity at the oxide-metal interface.