one of the scientific detection loads of Tianwen-2, asteroid thermal emission spectrometer based on the principle of Fourier transform spectral detection is the first spectral detector developed in China covering the thermal spectral coverage of 5~50 μm. In order to meet the requirements of light-weighting and low power consumption, the spectrometer electronics system adopts a design scheme that includes function modularization, circuit integration, and coupling front-end electronics with the opto-mechanical structure closely. On the basis of a mass of 1.8 kg and a power consumption of less than 50 W, the system has completed the functions of spectrometer power distribution, thermal control, laser high frequency stabilization control, interferometer subsystem high precision control, low noise and high dynamic radiation detection of celestial body signals, and multi-group mechanism control. The spectral resolution is better than 9.79 cm−1, the stability of the interferometer scanning speed is better than 99.5%, and the dynamic range is more than 53 dB. This paper introduces the design scheme of the overall system and each module, design results and verification, which can provide reference for the lightweighting design of the deep space exploration spectrometer.
Kinetic impact is currently recognized internationally as the most engineering-feasible method for near-Earth asteroid defense. Ground-based testing plays a critical role in impact effect evaluation and in supporting the design and implementation of on-orbit missions. The successful execution of the USA's Double Asteroid Redirection Test mission has systematically validated the effectiveness of ground-based test and evaluation methodologies, thereby providing an important reference for future planetary defense missions. As China is currently planning its first on-orbit kinetic impact asteroid deflection demonstration mission, there is an urgent need to develop ground test and evaluation capabilities. This paper reviews the major advances in international ground-based experimental research on kinetic impact asteroid defense, outlines the framework and methodological system for ground-based impact effect evaluation, and summarizes the principal characteristics of international research in terms of experimental content, test methods, and ground test facility configurations. In light of China's mission requirements, recommendations are proposed with respect to, among other aspects, capability integration, gap remediation, and diagnostic enhancement. This study is intended to provide a reference for the establishment of a ground-based verification system for planetary defense in China.
To address the demands of combustion science research in space microgravity, this study aims to investigate the flow-combustion coupling mechanisms of small-scale, weak-intensity turbulent diffusion and premixed jet flames. Supported by the Combustion Science Rack aboard the Chinese Space Station, a turbulent burner and a dedicated Particle Image Velocimetry (PIV) burner were independently developed. The apparatus utilizes a turbulence-generating grid to induce weak-intensity turbulence and incorporates an innovatively designed dual-solenoid-valve sealed tracer particle generation system to meet the diagnostic requirements of PIV. Subsequently, the apparatus underwent rigorous environmental testing and ground-based combustion experiments. The environmental tests verified the structural integrity and sealing reliability of the apparatus. Ground-based experimental results demonstrated that the methane diffusion flame maintains stable combustion at a flow rate of 0.08 SLM; however, at flow rates exceeding 0.10 SLM, buoyancy-induced nonlinear pulsations emerge with a dominant frequency of approximately 13.03 Hz. Furthermore, the stable combustion regime for premixed flames broadened significantly with increasing oxygen volume fractions. Additionally, the cold-state PIV experiments compared the perturbation characteristics of grids with varying mesh numbers, revealing that 40~60 mesh grids can effectively generate weak turbulence with a maximum central relative turbulence intensity of approximately 7.1%, therefore, a 50-mesh grid was selected for the flight model; hot-state PIV experiments successfully captured clear velocity distributions of the flow field. All technical specifications of the developed apparatus meet the design requirements, demonstrating its full capability to support safe and long-term scientific experiments on microgravity turbulent combustion aboard the Chinese Space Station.
When conducting space debris observation using optical payloads such as hosted payloads, the movement and attitude adjustments of the satellite platform cause inter-frame motion in the image sequence, directly affecting the accuracy of star map matching. Star image registration technology is an effective means to achieve image alignment and eliminate motion offset. Traditional astronomical image registration typically adopts a point- by-point matching strategy between point sets, but this blind point-to-point matching tends to generate redundant calculations and mismatches. Based on the space-based observation imaging model, this paper theoretically demonstrates the uniformity of star point motion in images and proposes a novel registration method guided by velocity fields—transforming the traditional single-point matching process into a globally optimized point set matching method. By fitting sample star points to the theoretical imaging model to determine their velocity field, the full image velocity field is then solved; this velocity field can roughly estimate the rigid transformation model of the image, thereby accelerating the star point matching process; the dual velocity field provides an effective motion prior, avoiding blind matching issues and significantly improving registration success rate and accuracy. Experiments on space-based images show that this method achieves a matching accuracy of 98.70% and a reprojection error below 0.09 pixels, confirming its potential application in the field of space debris observation.
To meet the requirements of ground-based electron irradiation experiments for a large-area irradiation field with low beam divergence, a compact beamline capable of simultaneous beam expansion and divergence compression was developed. The beamline comprises two sets of Halbach quadrupole magnets, one electromagnetic quadrupole magnet, and one solenoid, spanning a total length of approximately 1.9 m. Beam dynamics simulations were carried out to investigate the evolution of the beam envelope and transverse phase space throughout the beamline. The results demonstrate that the 90% beam radius increases from 0.76 mm to 25 mm, while the fraction of particles with divergence angles below 0.05 mrad rises from 3.60% to 52.31%, indicating notable effects on beam expansion and divergence compression. These findings confirm the viability of a hybrid permanent-magnet and electromagnetic lattice for achieving coordinated beam expansion and divergence reduction within a compact footprint, providing a reference for beam-optical design of large-area electron irradiation platforms under space-constrained conditions.
To address the issue of limited or missing automatic identification system information for certain vessels, this paper proposes a monitoring scheme based on a constellation of low-Earth orbit remote sensing satellites, with the aim of enhancing the reliability of vessel tracking. First, under the Bayesian framework and based on a linear Gaussian dynamic model, vessel trajectories are predicted, and methods for computing the detection probability of moving targets are discussed for both single coverage and continuous coverage sensor models. Second, to mitigate the problem of spatial dispersion of potential vessel regions caused by unstable data-downlink windows, a conditional Kullback–Leibler divergence-based approach is introduced to quantify the degree of probability backflow and thereby avoid ineffective searches. Furthermore, by jointly considering maneuvering metrics, divergence measures, and detection strength, a high-confidence attitude maneuver search strategy is developed to reduce the overall constellation maneuvering cost. Finally, target-of-opportunity simulations involving multiple vessel routes are conducted to validate the feasibility of the proposed scheme.
To advance the development of lunar-based astronomical observation and to support the realization of astronomical observation capabilities for the International Lunar Research Station, it is essential to systematically conduct quantitative analysis of the key technical indicators of lunar-based astronomical observation equipment. Guided by the three core scientific objectives of lunar-based ultraviolet-optical-infrared observation, this study systematically analyzes observational requirements and further develops quantitative equipment specifications, clarifying the core technical requirements of lunar-based ultraviolet-optical-infrared telescopes in terms of observational wavebands, aperture, field of view, and spatial resolution. Considering engineering feasibility and maximizing the achievement of scientific objectives, a multi-module lunar-based telescope scheme consisting of a large-aperture survey telescope, a small-aperture telescope array, and an extreme ultraviolet telescope is proposed. This work establishes a bridge between scientific requirements and engineering implementation, providing important technical support and references for the future development of lunar-based ultraviolet-optical-infrared telescopes.
To address the difficulty of precisely controlling the hopping motion of an internal torque-driven rover on the rocky terrain of an asteroid’s surface, this paper conducts a study based on the dynamic model of the rover, combined with a terrain generation method using a power-law distribution. Simulations reveal that rock size has an irregular effect on the rover’s take-off characteristics. Furthermore, the influence of different take-off positions on a terrain of the same rock size can be even more significant than the influence of the rock size itself. Based on this conclusion, a "trial hop-calibration" control strategy is proposed. By performing a short-range trial hop, the linear relationship between the take-off velocity (vh) and the flywheel’s angular acceleration (β) is calibrated. This enables the precise calculation of the control input required to achieve a target jump distance, offering a new approach for the rover’s take-off control on complex asteroid terrains.
Space debris clouds may pose collision risks to critical spacecraft within several hours after their generation. Existing risk assessment methods based on differential algebra and automatic domain splitting require repeated reconstruction of local Taylor expansions during domain subdivision, leading to intensive computational demand and considerable time overhead due to subdomain recomputation. To address this problem, this paper proposes a Lobatto pseudospectral discretization-driven method for short-term debris cloud collision probability computation within the velocity-space collision probability analysis framework based on two-point boundary value problems. The proposed method directly samples multi-revolution Lambert solutions at Legendre-Gauss-Lobatto (LGL) nodes and constructs Lagrangian interpolation. The derivative of the velocity increment is obtained using the pseudospectral differentiation matrix, and the collision probability over each time window is evaluated with Lobatto quadrature weights. Meanwhile, recursive bisection and local LGL discretization are performed under a prescribed error threshold to achieve the desired accuracy. Simulation results in a representative low Earth orbit scenario show that, after local piecewise reconstruction using the Lobatto pseudospectral method, the relative error of the velocity increment decreases from 1.57×10−2 for global single-segment fitting to 2.18×10−4. The cumulative collision probability of the debris cloud within 12 h after generation is 9.92×10−8, differing from the differential algebra result by 1.70%. Crucially, the computation time is drastically reduced from 201.124 s to 1.836 s. These results indicate that the proposed method reduces computational complexity and improves efficiency while maintaining numerical accuracy.
